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2005 SRX 3.6
56 Posts
Discussion Starter #1
At a bit over 50,600 miles, while driving slowly up a long gentle hill at about 35 mph, our 2005 SRX started making horrible, horrible noises and lost power. We got it as far as the parking lot immediately to our right before it died completely.

At the time I knew nothing about the 3.6 LY7 timing chain problems. I learned a lot in the next few days. Our car was well before the secret warranty early cut off, mid-year 2007. It had the second generation timing chain system. It had been maintained by the selling dealer when it was owned by my mother-in-law, and after she gave the car to my wife, I gave it Mobile 1 every 3000 miles irrespective of what the oil life monitor said. In fact, I changed it three times before I even ever saw the oil life monitor display a Change Oil message. We were responsible for about 16,000 of those 50,000 miles. The dealer maintained it for 34,000. Looking through the records, it appears to have received the oil life recalibration … and oil changes whenever the oil life monitor said to change the oil. In its short first life that was a very small handful of oil changes.

I have zero faith in the oil life monitor system.

In retrospect it had the typical chain noise, but I didn’t know what that was. It burned a lot of oil, about a quart every thousand miles, but we kept a jug of Mobile 1 in the back footwell and checked it frequently. It ran well. It had no codes. The car is pristine … and who expects a Cadillac to have catastrophic engine failure with so few miles? Knowing how quickly it burned or blew out oil, however, and how infrequently the monitor told the dealer to change the oil…that’s very scary, and likely the cause of the early failure.

Ours was not a minor failure. The left head dropped one valve and three others were badly bent. It was destroyed when the valve came back up into the soft aluminum combustion chamber. The rear left piston was holed, the cylinder wall very badly scored and gouged. The dealer said audio analysis indicated critical bearing damage. Two valves in the right bank were slightly bent. That head could have been salvaged, but the block and left head were both paperweights.

Initially I was going to do a light rebuild on a 2005-2006 used engine and swap it out. What I found was that good 2005-2006 engines cost three times what a 2007-2009 engine costs. They are difficult to find with low miles. They sell quickly. This engine is used in base Cadillacs from 2004 through mid-year 2007, and they appear to fail with alarming regularity. The castings and timing chain systems are unique to Cadillac vehicles with this first version of the engine design. No other application for the LY7 has the same major castings, which define accessory placement and sensor fitments. For a straight bolt-for-bolt swap, there is no choice except a 2004-2006, or a very early 2007 donor engine. And about that “early model year 2007” …. Be forewarned! Some references say that the 2004-2006 engines are the same, and some GM sources available to GM techs say that all 2004-2007 engines are interchangeable. The only way to go is to verify the casting numbers. The 2004 through early model year 2007, first and second gen timing chain system engines are casting numbers 12586559 for the block and 12581596 and 97 for the right and left heads. Nothing else will fit; the water pump, engine mounts, or other accessories or all of the above might be in the wrong locations.

With some coupons and careful shopping, I found a remanufactured long block that was less than $4k delivered, and that includes the core deposit I have no hope of getting back. Compared to a low miles used engine – when you can find them – going for $2500 to $3000, I count that a great deal. The car is only worth $9k in great shape…. But, as I said, it ran well. It was good for trips and daily driving and Costco runs and it was easy to drive and provided a good compromise between smaller car efficiency and truck and big SUV visibility. The interior is pristine and it’s comfortable and the A/C is ice cold. There’s no way on the planet we can replace it for $3900. So here comes the remanufactured engine.

The long block arrived dripping in assembly lube in a big plastic bag in a plastic pod on a pallet, nice and safe. There was no oil pan, flywheel, intake, valve covers, or accessories – a classic long block. Heads were fitted and the problematical timing chain system was hidden under the huge and complex front cover.

There is no good way to swap the LY7 in the SRX whole. By the book, the whole engine has to come out underneath on its subframe with the transmission attached. The reason for this is that some of the engine-to-transmission bolts are inaccessible with the heads, intake, and thermostat housing installed. Now, I started the tear-down expecting to find, at worst, some bent valves, but I didn’t expect to pull the engine. So my engine is torn down almost to the short block in-place. To pull the engine out from underneath at this point would be a lot of extra work, so I really need to build it up in-place.

I’m not going to cover the short block removal, as it’s the reverse of the install. From the point at which the heads are off to pulling the short block isn’t that much work, provided you know the traps along the way. And as for those traps… I got a 3-day subscription to AC Delco Technical Data Service online and downloaded every single webpage module relevant to second timing chain version engine tear down and re-assembly. I’m not going to tell you how to do that. You can work with a laptop on your workbench over the three days if you’re fast or longer if you buy a longer subscription, or you can print them out on 3-hole and alphabetize and tab them in a binder – which is what I did, all 1200+ pages. You will need the manual for torque specs, if nothing else, and to the best of my knowledge there is no printed maintenance handbook available for this car or engine.

Here we go. Remember I’m starting with the short block out of the car already. See later steps and run in reverse if you need to get there first from the point at which you discover your failure.

My engine came with both “upper” and “lower conversion” gasket sets. Not realizing the engine would arrive with those, I bought some premium Fel-pro sets too. Thus, sometimes you’ll see blue gaskets, and sometimes you’ll see orange.

All references to “right” and “left” are vehicle right and left, unless otherwise noted.


Remove the oil pan from the old loose short block. There are a ton of bolts, all the same except for two very long ones along the back edge. There are some pry points around the bottom edge of the pan, front and rear, that allow you to separate the pan relatively easily. None of the bolts are hidden. If there’s the least little hint of resistance while you’re trying to pop it lose, you likely missed one, however.

Dismantle the drain plug, oil pan clean-out plate, windage tray, and oil pickup. These things are not particularly complex, but they have to be clean going back together. My pan was full of piston and valve fragments, and they tended to wedge into the gaps around the edge of the raised portion of the clean-out plate at the bottom, so spend some time getting all the bits and pieces out of the sump. Be careful not to damage the oil level sensor connector body on the outside of the sump or the sensor pickup on the inside. Be careful with strong solvents unless you remove that sensor, too.

Scrape all the old gasket goop off all the surfaces. Be careful not to scratch the surfaces badly.

I used some high intensity lights, mirrors, and a lot of compressed air to clean out the oil pickup. The screen was full of little bits of alloy, and smaller bits were in the pickup tube stuck to the walls. Don’t skimp on time here. Pieces will also hide under the lip that holds the screen in place. Run flexible rags around in there, use little mirrors, lots of compressed air. Make sure everything is CLEAN. Don’t leave any pieces of metal , no matter how small, in the oil pan or associated assemblies.

There’s a new oil pickup gasket in the gasket “lower conversion” gasket set. Replace the old one. Make sure your new RTV application is nice and even. You get to practice on the clean-out plate, which is great because you’ll be doing a LOT of RTV application on rebuild on similar surfaces. Re-assemble the drain plug, clean-out plate, oil pickup assembly, and windage tray. See your manual for torque specs. Put your cleaned and re-assembled oil pan aside.

If you can’t do this part without reference photos, you do not want to attack the rest of it.


Now, if you tear down your new remanufactured engine you’re probably going to void any warranty you’ve got. Me, I have little to no faith in someone else’s rebuild procedures, and I know the engine has a better chance of living if I build it up in place installed than if I try to shoehorn it in as-is. I also really want to verify the timing chain setup. I don’t want to install a new engine with a 2004 first-gen timing chain system. I’ve got no qualms about tearing it down. After all, I already tore one down, so I know how it’s put together.

Let’s assume your new engine is on a stand, right-side up. Remove the eighteen to twenty-two bolts holding the timing chain cover on – the rebuilder might be expecting you to re-use some of the twenty-two bolts you have. There are or should be five long ones around the water pump mounting pad and the rest scattered around the edges of the cover. When I took the cover off the old engine in-place in the car, I had to use the pry points along the edge with the oil pan to pop loose that edge, and the rest followed. The new cover on the new engine is torqued or warped a little – this moderately concerns me – and pops loose immediately on its own as soon as the majority of the bolts are out. The old cover has steel liners riveted in place at three locations. The new cover has had these rivets ground out and the liners removed. I’m not sure what function they served, but I can imagine a lot of gunk and bits hiding behind them, so I’m glad they’re gone.

A note – when removing these timing covers, don’t bother trying to use the “bolt jacking hole” just to the right side and above the water pump pad. You need a metric bolt about 60+ mm long with threads along its entire length to work in this hole, and I couldn’t find that bolt. I used nothing but the jacking points along the edges of the cover -- recesses with big, beefy blocks visible for prying. They work.

The timing chain installed by the rebuilder is very different in detail from the original parts. The color of the plastic guides is different. The chains feel different; they ring differently. There’s a more finished look to the brackets and guides and tensioners. It’s still a second-gen system – the third-gen system that carries the GM 120,000 mile warranty fits only in newer blocks -- but all the new parts are marked “GM – CLOYES – USA”. This is very good. The old parts – the chains that stretched to the point of allowing the head crash -- weren’t marked at all.

Clean off your new timing cover – scrape all the gasket material off, and out of all the little gasket pressure holding slots in the sealing surface faces. Don’t touch the new VVT actuator solenoid grommets or the front main seal that are already installed, and don’t damage them with solvent.

At this point I find my paranoia was justified. The cover-to-block main water passage seal that fits into grooves around the main water pump cavity dropped loose during assembly and a loop of it was folded back and cut off by the timing cover edges. This new engine would have had a massive coolant leak inside the front cover if I’d run it out of the box.

Finish cleaning off the front cover and put it aside.

2005 SRX 3.6
56 Posts
Discussion Starter #2

Back to the new engine. Find top dead center. The AC Delco TDS manual sections will tell you how to find TDC. Basically, you’re looking for the point at which both left “L” marks are in the positions illustrated on the left camshaft sprockets, and the left idler sprocket’s big pointy timing mark is pointed straight up, and the timing mark on the crank is low on the left side and the key for the main crank sprocket is approximately top center or a little off. The new AC Delco TDS manual apparently is a lot better than the old manual discussed in other online procedures, and there’s no shortage of discussion on timing these engines. I won’t duplicate that material. Don’t waste time trying to line up the chain timing marked links; chances are the engine has been turned over a few times to test compression and the marks only line up at assembly. After that, the marks precess until they happen to line up again – a function of the number of sprocket teeth, total chain link count, etc. – likely hundreds or thousands of revs down the line. Don’t waste your time on the chain marks. Use the marks on the cam, idler, and main sprockets only. Find TDC and install a pair of EN-46105 cam rotation lock plates at the back end of the cams. At TDC they only fit one way. You will find material online that says these are optional. Buy a set used and don’t waste any time. They keep the cams fixed in place all through tear-down and reassembly. You don’t want to risk not having them. They are hugely convenient timesavers.

Here’s a photo of the cam rotation lock plates along with the crank rotation lock tool I discuss shortly.

I took an additional precaution and I used a sharpie to match mark the main crank sprocket and oil pump, so that I don’t have to rely on any other marks to keep the crank at TDC.

Remove the right bank secondary timing chain, guides, and tensioner/guide assemblies. I could tell you to put these pieces in a clean new plastic bag or something, but if you’re tackling this you know how to put these nice, new, clean pieces aside. Next remove the right idler sprocket and primary chain, tensioner, and guide assemblies. Finally, remove the left idler sprocket, left secondary chain, and left tensioner and guide assemblies. Put all that timing gear aside.

Now is a good time to check to make sure all the cam cap bolts are tight. Mine were.


Now is a also good time to swap over the exhaust manifolds, while the new heads are attached solidly to the new engine on the stand. Break the manifolds lose from the old heads and discard the old heat shield/gaksets. Clean and inspect the manifold bolts. Clean and blow out the exhaust manifolds. Mine were full of oil and debris from the failure. Install new heat shields from the upper gasket set with the manifolds and use some anti-sieze on the manifold bolts. The exhaust manifold heat shields appear to be GM-only parts. Both the Fel-pro set and the supplied Victor Reinz set had the very same heat shields in them. Torque to spec.


Remove the head bolts. The right bank only has eight. The left, ten, the eight big ones and the two little ones up front just inside where the cover will be. Discard the sixteen big ones. By the book you’re supposed to replace the two little ones on the left bank, too, but the torque specs for them indicate that they’re not nearly as critical as the others, and I have my doubts they’re actually torque to yield like the main bolts. Again, by the book you should replace the two little ones too – which means pulling the two left bank cam sprockets or the left cams entirely. I felt that was riskier than re-using the small bolts.
At this point my paranoia was validated again. Two of the main head bolts had not been torque down. They required zero effort to remove – to say they were “finger tight” would be an exaggeration, but they hadn’t been torqued. They might have been torqued to the first pass spec, but never subjected to the second pass.

Tape, wire, or block the cam locking plates in place. Don’t use paper towels or rags to block them in place because that material could wick assembly lube from the rear cam bearings. Pull off the left head and put aside. Pull off the right head and put aside, with great care. The right head has valves protruding; take care not to bump or put weight on them. Don’t prop up the head somewhere where it might fall over.

Clean off the head and block mating surfaces. This was a new install and required only a light wipe-down with some engine oil for me. Discard the cylinder head gaskets.


Flip the new engine over and clean the assembly lube off the oil pan sealing surface sides and rear. Now is probably a good time to check crank endplay on your new engine. I was a little concerned that mine was too loose, but it turned out to be at the upper end of the allowable range. The block is aluminum, so you’ll need to use a little ingenuity to place the dial indicator. Speaking of which, here’s a great reference to things like the crank end play:

While you’ve got the engine upside-down, take some time to look at one of the good features of the LY7 – those massive, deep-skirted, six-bolt, cross-bolted mains. That’s serious engine design. Remember that this engine was supposed to the basis of an entirely new high performance V6 engine family for GM. Ultimately I suppose it has been – but there have been a lot of changes to the design and it’s not the “LY7” any more. I took this opportunity to verify that all the main bolts are tight. They were.

Apply an even and thin coat of sealant and place the pan in place, and torque all the bolts. The two extra long ones in back are much lighter duty and have different specs. Double check your pan sump clean-out plate bolts and the drain plug. Reinstall the sensor if you need to.


Remove the crank position sensor from the old engine. It’s held in with a single bolt, on the right side, high up under the cylinder bank, just ahead of and above the flex plate dust cover. There’s also a heat shield stud you’ll need to move from the old engine to the new one on the ride side, about mid-engine. Swamp the crank position sensor and the stud to the new engine.

Remove the flywheel from the old engine. Let’s digress a bit and discuss another of the “special tools” referenced in the documentation: the EN-46106 Flywheel Holding Tool. I bought one of these on ebay used before I started on the tear down, and I found it was completely useless because it installs through the starter hole. That’s utterly inaccessible early in the tear-down, so I found another way to fix the crank. However, for build-up it’s vital. Don’t waste any time; pick up a used one. If you’ve got your engine on a stand you already have the bolts you need to hold the tool in the starter hole, so install it on the old engine and break loose the flexplate bolts.

By the book, the flexplate-to-crank bolts are single use torque-to-yield fasteners. However, you won’t find them easily. Supposedly Cadillac has actually discontinued them. If I remember correctly they’re M10x1 fine, about 12 to 15 mm long, a set of eight. Most GM and aftermarket GM flexplate-to-crank bolts are 7/16-20. Most parts shops will try to sell you a set of those for the Caddy, and they won’t fit, and you’ll have to return them and lose a day or two. ARP does make a set, but they use a funky head design and they’re generally out of stock online. I checked in with some Cadillac techs and I was told that they re-use these original bolts all the time. I’m not going to tell you to do that. You should buy new ones, by the book, and follow all torque specs to the letter.

I re-used my old ones. I looked up a typical and comparable torque spec for M10 fine bolts in similar applications, and I used red locktite. I’m confident they’ll be fine. The torque I used didn’t push them back into yield, and the resulting compressive force should be several factors of safety greater than the highest possible torque loading the interface will see. And the red locktite will guarantee they never back out. Ever.

The manuals note that thread sealer is essential on the flexplate-to-crank bolts not only because of the severe duty, but because you’ll get an oil leak if you don’t use any. The crank in my old engine has bolt holes on the rear flange that pass through the rear flange. Thus, the bolts enter into the oil volume and the threads can wick oil out to the flexplate. The new engine has a crank with blind bolt holes on the rear flange, so this can’t happen. I used threadlocker because the bolts were used and I didn’t want to push them into yield again, but the new style crank doesn’t have the oil leaking issue. So no worries there.

So move the EN-46106 back to the new engine and install the flexplate. Again, you SHOULD use new bolts and follow the specs precisely. You shouldn’t do what I did. Nope, nope, not at all.

The last thing you need to recover from the old engine besides the flexplate, oil pan assembly, crank sensor, and the odd studs is the water temperature sender. This is located outboard, center, high on the left bank, just ahead of where the dipstick tube was located. You can’t miss it. Move that to the new left head assembly.


2005 SRX 3.6
56 Posts
Discussion Starter #3

Flip the engine upright and find a way to plug the big opening at the front and bottom of the engine around the oil pump, skirts, and oil pan forward edge. Things will try to run in there and hide while you’re working on the engine, and I don’t think you want to be pulling the pan again, because it would be a real pain to snake a flexible grabber past the windage tray. Also tape off the entire head gasket mating areas so nothing gets into the cylinders, water jacket, or oil passages.

Your short block is now ready to install into the car.

My transmission is held up at this point with my custom SRX transmission support tool. This is a length of 1” schedule 40 iron plumbing pipe 36” long plus a piece of 3/8” plywood 3” by 4”. With the pipe – which is also my ½” drive breaker bar extension, because the Craftsman ½” drive fixed bar slides into it perfectly – slid in place above the aft ends of the two back corners of the engine subframe, and the plywood top center on the pipe, under the leading edge of the transmission bellhousing – the transmission is supported perfectly in its correct position and attitude.

On the block there are four square bosses at the four corners, just below the cylinder head mating surfaces. These are used for ground studs and such. Examining them you’ll find they make perfect lift chain attachment points. Or three of them will. I examined three – not the right rear boss – and found them all threaded with M8 coarse holes. I figured I could use two lengths of 6mm nominal high strength lift chain in an “X” for safety strung between the bosses and crossing over the center of the engine. I cut two 28” lengths of the chain – which worked out to 29 links -- and got some Grade 10.9 M8 20mm bolts with some washers.

And then I found that the rear right boss isn’t tapped with an M8. It’s got a much smaller M6 hole. Of course. The one I didn’t check.

The short block with the pan is pretty light – only a couple hundred pounds. There’s no problem lifting it with one length of high strength chain. But I would have been happier with two. The engine balances nicely on a hoist with the one length of chain strung between the front right and rear left ground lug bosses, where you can use the M8 bolts.

I use a standard, Harbor Freight 2-ton shop hoist with the foldable legs and the extensible jib. It’s never disappointed me. Because the engine sits so far back in the SRX, the jib interfered with the hood getting the engine over the fender – I had to come in from the side because of space limitations in my shop. I didn’t want to remove the hood or prop it so far open it would risk falling back and cracking the windshield, so I removed all but two links of the hoist’s chain and hook and rethreaded the chain higher up in the jib. With the jib fully extended, that let me pick the engine off the stand, roll it over the left fender, and lower it into position.

Another note is appropriate at this point. There are so many steps in these procedures where you have to lower the car, raise the car, lower the car, raise the car, again and again and again, you really need two jacks because there’s no good place to use one on centerline, forward. I used a pair of 3-ton hydraulic jacks from Harbor Freight, 68048, one on either side at the jack points inboard on the unibody stubs, aft of the fenderwells. You can use one, going from side to side, using jackstands, but it will cost you a lot of time and aggravation. I would just jack up both sides, place adjustable jackstands under the subframe, crawl under, get out, pull stands, lower both sides… etc. Much faster!

My front wheels and tires are off. It simplifies everything. When I say “lower the vehicle as far as possible”, the jacks are almost bottoming, so the front disks are only a couple inches from the shop floor. This really facilitates diving into the engine compartment from up front.

Lower the vehicle as far as possible. Swing the short block and pan assembly into position. Lower and shift rearward in stages, by inches. Your goal is to line up either the uppermost right or left engine-to-transmission bolt first. Once you do that, the rest is easy.

There are ten engine-to-transmission bolts, all alike. Nine run forward through holes in the transmission. One, located under the right bank near the crank sensor, runs rearward through the engine rear flange. Four bolt the transmission to the pan; six, the transmission and block. The lowermost left transmission-to-pan bolt holds a bracket carrying some electrical harness. Don’t forget to thread the bracket when installing it.

Lower and shift the engine into position until you can catch one of the upper corner bolts. Once you can catch one of the upper corner bolts, jiggle and wiggle and raise and lower the engine until you can catch the other upper corner bolt. Once you have two, it’s just wrenching. Jiggle the engine until you feel the dowel pins and the torque converter pilot slide into place. When this happens, the engine will slide aft easily until it’s flush with the transmission. Raise and lower the car, and raise and lower the engine until you have all ten bolts in place. Wrench some bolts until the engine and transmission slide completely together. With careful jiggling and balance and lifting, it should be possible to slide the engine completely into position while turning the bolts with finger torque only. This guarantees no misalignment of the dowels and torque converter pilot. Under no circumstances torque any of the bolts to force the engine into position!!!

Once the engine is installed and all the way aft, and all ten bolts are in place, torque them appropriately.

Your special SRX transmission support will take the weight of the engine, which should still be partially supported by the hoist as well. At this point, find a convenient height at which you can reach under the car to grab the special SRX transmission support (pipe), AND at which you can reach into the engine bay as far as the engine mounts. Now gently lift the engine and transmission weight off the pipe with the hoist, and reach under the car and remove the pipe from the subframe. The special SRX transmission support pad (plywood) will fall out as well.

Under no circumstances allow the hoist to lower the engine any further. There’s plumbing and wiring that will be pinched and damaged by the engine moving too far down into the bay.


Place the left and right upper engine hard mounts into place. You may need to wiggle the engine side to side a bit to get both to fit, but they will slide into place and then drop down against the block on both sides.

Note: you can’t lower the engine into the bay with the mounts bolted to the block because the dowels and converter pilot are too long and the main engine mount studs too tall to allow the engine to move forward and up enough to clear the dowels and pilot while the engine mounts are present.

Once you can place both engine mounts, install and torque the four engine mount bolts on each side. You can get to all of them through the engine compartment and to many of them through the fenderwells.

Note: we had a pronounced THUMP during normal driving that was our only complaint with the car. We couldn’t find it. The dealer couldn’t find it. No one could find it. Sometimes on shifting, cornering, or braking… THUMP THUMP. It had been getting worse, very slowly. On disassembly I found it. All four of the right engine mount-to-block bolts were loose. I don’t think they had never been tightened.

Once the eight engine mount bolts are torque to spec, lower the hoist and install and torque the two main engine mount stud nuts. They’re probably single use, too, but a little blue threadlocker should take care of that – and the engine is never going to fall up off the mounts. Remove the hoist and chain across the block.


Before you continue and forget, hook up the electrical connector to the oil sump oil level sensor bottom center of the sump.

At this point what you’ve got should be like what’s shown in the image. The heater hoses are tied off to the vehicle right. The engine injector harness is pulled ccw around and away from the engine, right side forward. The power steering pump and A/C compressor are tied back to vehicle left and forward. The main rigid cooling line is disconnected and plugged and shifted outboard and up. Cooling line and brake line brackets that attach to the sump bottom center forward and left side bottom forward are still disconnected.


Now is the time to install the torque converter bolts. The originals should have been discarded as single use, but the most commonly available new ones – a set of four oversize head M10x1.5 commonly found on a HELP assorted hardware card aren’t quite right. First, you only need three, but if you lose one it will almost certainly be inside the bellhousing so let’s hope you don’t do that. If you install them off the card they’ll appear to fit perfectly until you rotate the engine to install the second one… at which point you’ll realize the heads are a bit too tall. I got out the belt sander and I knocked the little ridge around the edge of the heads down a hair, being careful not to heat the bolts too much. Then I installed them with blue threadlocker to specified torque settings. Install them one at a time through the starter hole, turning the engine over clockwise only ( it’s the valve train that should only be rotated that way, but it’s good to establish the habit now ). After all three are installed and seated, make the second and third passes to the specified torques, turning the engine slowly to each bolt location. What works best to reach the converter bolts are a half-inch wobble 16” extension on the end of a 12” straight ½” extension, which allows you to work the torque wrench ahead of the engine entirely. Return the engine to TDC ( remember the sharpie mark – makes it easier when the pistons are covered up ).


Install the starter – two bolts – and the starter electrical connections – one single conductor connector and one ring terminal with brass nut. Verify that the integral solenoid-to-starter connection that need not be disconnected to remove the starter is still tight. At this point you can also reinstall the left bank anti-knock sensor – which should still be attacked to the engine harness -- but do not tighten that sensor’s bolt.

One of the two starter bolts can be accessed poorly from above. The other one can be accessed poorly from the fenderwell or from below the car.


Install the lower thermostat housing. Use a new gasket and high temperature gasket compound. Make sure the inside is clean. Fit a new rubber doughnut seal from the upper engine gasket set to the central line before installing it. Note in the second picture

the black rubber transmission breather line poking up behind the thermostat housing. The little plastic cap that goes on that is one of the pieces that tries to run off and hide, often. Don’t re-install it yet – all the work we have to do with harnesses and heater hoses and EGO sensor connections would surely knock it back off, and then that little plastic cap will hide in amongst the buttresses and braces of the topside of the transmission, like it did during teardown.

2005 SRX 3.6
56 Posts
Discussion Starter #4

Install the oil filter housing. The four lower bolts can’t all be reached if the power steering pump is installed, so you’ve got to do this first. Use a new gasket – the Fel-pro piece looked far superior, but I’m a fan of metal gaskets for oil pumps, so I used the Victor Reinz piece that came with the engine. Avoid using compound on the oil filter housing base; you don’t want to push leftover gasket compound into your main oil gallery. What is OK is high temperature spray-on gasket sealer. I used some of that, just in case there are small imperfections in any metal sealing surface.


Next, install the A/C compressor and power steering pump brackets. At this point just install the single bolt that holds the power steering pump bracket to the left upper corner of the block, front top left. However, there are five bolts that hold the A/C compressor bracket in place – three that bolt through from the front into the block, left side, and two that bolt through at the rear of the bracket from the left side of the vehicle into the block. Those two can be reached from the fenderwell using a pair of 12” to 16” drive extensions, behind the axle centerline, just below the inner fender structure, immediately behind the A/C compressor. They are nearly impossible to reach without the long extensions. Don’t tighten the single power steering pump bracket bolt.


Install the upper thermostat housing with thermostat and the heater lines. Use new o-rings and gaskets and an appropriate application of high temperature gasket maker. These gaskets and o-rings are not in the upper engine gasket kit. The main thermostat o-ring comes with the new thermostat – and you’d be a fool not to install one while it’s this easy to get to – but the lower heater hose o-ring needs to come from a kit, and I made the upper heater hose gasket from stock.


Next, move over to the right side of the engine and free up the lower engine harness branch if it’s tied back somewhere. This is the branch that runs to the right anti-knock sensor and the crank position sensor. Hook up the crank position sensor at the back of the block, install and torque the right anti-knock sensor, which should still be hooked up to the harness – do NOT allow the body to contact the engine mount in its installed position – and make sure the big square ground lug lines up below the square threaded ground boss at the front upper right corner of the engine. That’s the lug you used to lift the engine into place.


At this point I moved back to the left side of the engine and installed the dipstick tube. This o-ring is in the lower engine conversion kit. I used a little bit of RTV too to help hold it in place. You’ll note that the dipstick tube bracket that normally bolts to the head has been cut off. I did that. Here’s why: during disassembly, when you’re trying to pull the left head, you need to remove the dipstick tube because that bracket won’t fit through the hole in the header and heat shield through which the dipstick runs down to the block. So… you need to remove the left anti-knock sensor so the dipstick tube comes out before the head lifts off. However, you can’t really get to the left anti-knock sensor from underneath. Oh, you could if you had a spider monkey for an assistant, but I couldn’t reach up from underneath to access the sensor. So I cut the bracket off and left the dipstick tube in place when I pulled the head off over it, and THEN removed the anti-knock sensor and dipstick tube. Way easier. Of course I have to make a new bracket. More on that in a bit.

Now you can tighten the bolt on the left anti-knock sensor. Don’t allow the plastic body of the sensor to contact any part of the block; rotate it until it’s clear of any other part of the casting. The sensor body should reach over the dipstick tube, which is why you can’t pull the tube with the AK sensor installed.

Note that if you leave your dipstick tube bracket intact that you’re going to have to thread it through the header and heat shield and down to the sump blind later, and then somehow get up in there over the starter and under the manifold and mount the left anti-knock sensor after. The book says it’s possible. I really don’t know how that could be true for an installed engine.


Next, I moved back to the right side of the engine and installed the hex-head stud that holds the square ground lug in place at the right upper block square ground boss, with the ground lug under it. Then I installed the right side lower sensor heat shield onto the three studs – the one visible that points forward from the converter dust cover, the one on the boss, and the one in the middle you moved over from the old engine. The heat shield was held on with stupid little one-use push-on sheetmetal nuts. At AutoZone I found a Help card that contained a pile of “self-threading” sheetmetal nuts. None of them are the right size, but there’s one size that’s almost right, a little small. With an 8 mm deep socket, a small hammer, and a pair of needlenose pliers mounted closed jaws up in a vise, I opened up the hole in that size until they threaded onto the metric studs perfectly. They are visible in the photo in the two locations that can be seen.


Time to install the left bank’s head assembly. I didn’t want to reach over into the engine compartment and lift this into place over the dipstick tube and risk damaging the head gasket coming down. This made it easy. I used nylon straps around the header and around two of the inboard camshaft lengths at the ends that have those spindle-shaped sections with the ridges at the bearings. This allows you to place the nylon straps so that they don’t contact the bearing edges, where they might wick assembly lube out of the bearings. This is important. Remember also that nylon and oil don’t get along well, either, so this should be a single-use application for the straps, which are a out of a $10 kit from HF. My back, which is not nearly as resilient as it was when I started swapping engines 35 years ago, says it’s the best $10 I ever spent.

You’ll know where the dipstick tube threads because there’s a notch in the gasket/heat shield between the manifold runners that frame your target.

You might notice that my head gaskets are copper-colored. When I tore the engine down I found the rebuilder’s gaskets coated with a copper-red goo that resembled half-dried red threadlocker. That surprised me. I’ve always been a dry head gasket person. I didn’t know that using high temp head gasket assembly sealer had become commonplace. That’s Permatex spray-on head gasket assembly high temp sealant, about eight bucks a can. I figure the rebuilder had a good reason for using the stuff, which is recommended especially when assembling high mileage aluminum heads and blocks with metallurgically lined – as opposed to mechanically lined – cylinder bores. Helps to enhance the seal where there might be tiny bits of surface warp. It also provides a way to apply a safe coating of sealant to the metal oil filter housing gasket discussed earlier so there’s no risk of pushing extruded RTV into the oil galleries. I likey.

Oh, and don’t forget that last wipe-down of the head and block surfaces before dropping the gasket into place. I use a lint-free finishing cloth with a little bit of gasoline, and then drop the gasket, and then lower the head. Minimizes lint and dust falling on the surfaces.

Time for the head bolts. I got new Fel-pro sets from Amazon. Each set comes with the eight big bolts and one little one, someone having figured out that the two heads together need sixteen and two, but not that the two small ones are on one side. As I said before, I’m not going to replace the little ones. They’re not critical to head compression, being all the way out at the corners and the right head not even having them at all. I also picked up the easy-to-use bolt rotation gauge from Amazon to verify correct bolt rotation subsequent to the torque pass. In fact, the gasket sets came from Amazon too. The prices for the tool and for the gaskets and bolts were the lowest anywhere:

2 each Fel-pro ES 72274 Head Bolt Set

Fel-Pro HS26376PT Engine Cylinder Head Gasket Set

Fel-Pro CS 26376-1 Engine Conversion Gasket Set

Lisle 28100 Torque Angle Meter

This was my first experience with torque to yield fasteners. However, using the torque angle meter is easy. I installed it with a 2” fixed ½” drive extension under it and used an 18” breaker bar. You take that little clamp and affix it to something convenient, and then route the flexible steel line so that the meter wheel is fixed in rotation. Then, you release the thumbscrew and set the needle to zero. Thereafter it reads any additional twist to force into the bolt. Easy.

Torque the bolts to spec – multiple passes, at least one for torque and one for angular displacement. I found the most difficult part of this process was overcoming my natural resistance to twisting the bolts far beyond what “felt right”.


2005 SRX 3.6
56 Posts
Discussion Starter #5

Now that the left bank head is on you can install the second power steering pump bracket bolt and the fifth and last oil filter housing bolt. You can see near top center the last oil filter housing bracket bolt and the sliding collar in the bracket itself that the bolt mounts to the head. The bracket can actually slide along that collar a little to allow for vibration and mounting variation. The second power steering pump bracket bolt is shadowy, immediately below the oil filter housing bolt and barely to the right in the photo. You can just barely see the bolt head, immediately left in the image of the visible red seal insert at the back of the oil pressure sensor. This bolt is one of the more challenging to reach, even with the convolute heat-rotted off the oil pressure sensor harness branch. There’s no real good way to get it more than a tiny fraction of a turn each grab. Tighten it and the first power steering pump bracket bolt out front. The last bolt for this bracket bolts to the front cover, but tightening these two won’t hurt placement of the cover. If anything, it helps because the bracket becomes a fixed position you can use to guide the cover into position.


Here’s lifting the right head into position. Remember to be extra careful with this side because of the extended valves. Sure, I could have removed the cam rotation plate and rotated them in, but I didn’t think of that at the time. AND I’m not sure I would have, because the whole point of the cam locking plate and sharpie mark exercise is to keep the timing in precisely the same state it was in when I pulled the heads. Doing that dramatically simplifies re-timing the new engine’s timing chains. Given that this is an interference engine, I’m much happier handling a fragile head than figuring out how to rotate valves back into TDC when they’re sitting over pistons.

Lowering the right head into place.

Install the head bolts and torque them down to spec, and then twist them to the specified yield angle with the meter.


After the heads are bolted down it’s time to assemble the timing system. I’m not going to duplicate the effort of some truly awesome online discussions here on the timing chains. I will, however, make one note about the AC Delco manuals, and discuss in detail one procedure I didn’t seem to find documented anywhere.

First, the version of the manuals I got is clearly much more evolved than the version discussed on other posts. My online version didn’t have the problem with right and left symbols being swapped in figures while the text was correct. The online version I got early this year has both correct figures and correct text. If you follow the guide, you won’t make any mistakes. Moreover, if you used camshaft rotation lock plates and made a “personal” TDC match marks on the oil pump and primary crank timing chain sprocket, all you need to do is reinstall the chains, guides, idlers, and tensioners and make sure the marks still all line up. And you’re done. You won’t even have to mess with the “second stage” timing because both heads were locked down at TDC and you’re putting everything back just the way it was.

Now, the second comment I promised – all online materials and discussion threads I found simply have you installing the fully retracted tensioners and pulling the grenade pin out once installed and lined up so that the tensioner falls into place.

But what if you’ve just torn down the engine with new timing chain components, and you don’t have the pins, and you can’t seem to get the tensioners retracted far enough to fit during install?

If you don’t have the pins at all you can substitute a very fine drill bit or allen wrench. I actually had a set of pins….

I started accumulating parts for my rebuild before I discovered I needed an entirely new engine. Thus, I was sitting on an AutoZone timing chain set as has been discussed in other threads. Now, apparently that part number used to get you the Cloyes TrueRoller US-made set that’s installed in my rebuilt engine. That’s not what I got. I got a Taiwanese-made set. It’s still sitting in the box unused. I have no doubt it’s superior to the Chinese mainland-manufactured sets around, but I don’t believe it’s likely to be as good as the US-made Cloyes set in my new engine, either. I figure if I hang onto it, one or another of Murphy’s corollaries will mean there’s a reduced chance of my ever needing it…

Anyway, so remember I’ve pulled my timing set bits from the new engine, bagged ‘em, and now I’m reinstalling them on the engine with the short block and heads in place in the car. ( Make sure you use tons of assembly lube, especially on the rub surfaces of the plastic tensioner plates. ) Everything goes fine… but I can’t seem to get the tensioners to retract far enough to fit. There’s just not enough length in the chains for things to fit. I’m pulling my hair out trying to figure out what’s wrong. I pull my old used tensioners out of the scrap bin and compare, and they retract just as far as the new ones. But there’s no room. I can’t get the very first left bank secondary guide and tensioner components to fit. I try all possible orders and assembly sequences, but nothing helps. Given the critical nature of these components, I don’t want to force anything, but I’m beginning to think I’m doing something horribly wrong.

I was.

Finally, I opened up the box of the new Autozone Taiwanese-made set and I pull one of the tensioners, and I find that its retracted position, retained with one of the pull pins, is fully a quarter of an inch shorter than anything I can get out of the new tensioner by squeezing it.


Well, the tensioners have an anti-retraction mechanism. Once they extend, they cannot normally be retracted again in increments unless specific procedures are followed. They extend. They ratchet and lock. This means that no amount of chain slap, no backfire, or windup will force the tensioners to retract into a position that allow the chains to slip… as long as the chains are in spec and don’t stretch too much. Once they stretch too much the system fails anyway…. But that’s why we’re here, isn’t it?

Take a look at this photo of the disassembled tensioner piston and housing.

The tensioner provides three separate methods to tension the chains: first, oil pressure pushes the piston out. Second, the spring internal to the piston provides a minimum spring force. And third, that jagged spiral groove cut around the shaft of the inner piston assembly provides a lock against retraction. If you look very carefully at the inside end of the outer piston, you’ll find the telltale marks of the pin that’s fitted that protrudes into that groove. If you twist the outer piston while retracting it, you can force that piston to retract entirely over the inner piston. Now look at the end of the spiral groove at the end of the inner piston. See, whereas over most of the groove there are ratchets that keep the outer piston from closing, at the inside end there’s a reversed ratchet that keeps the outer piston from extending once it’s retracted fully and twisted into place!

You need a thin 13mm open end wrench for this.

Remove the piston assembly from the tensioner body and, either with very tough, stiff gloves or with something like a pair of small leather pads at the ends of the piston, compress the piston between thumb and forefinger of one hand. You need to keep the smaller diameter inner piston from rotating. While you’re doing this, twist the outer piston with the wrench on the outside end flats. You can feel the outer piston ratcheting down through the spiral. At some point it reaches full retraction, you give the thing a last twist, and it’s locked in the compressed position.

Note that the locked retracted position isn’t as retracted as it will be when the pin is installed. So lube it up, drop it into the tensioner body, get your locking pin ready, compress the piston a bit with thumb and forefinger, and install the locking pin. On the two secondary tensioners the locking pin goes through the tiny hole and along the shoulder edge of one of the 13mm wrench flats on the outer piston. On the primary tensioner, the pin goes through the hole in the plastic guide and into a matching hole in the housing at the inside of the tensioner mounting surface. When the piston is fully retracted and locked in the reversed ratchet at the end of the spiral groove, that last little tiny push will pop it out of the locked position and force the outer end against the pin. At that point, when you pull the pin after installing the tensioner, the outer piston flies through most of the groove into an operating position and can’t back up again, which is why it’s not possible simply to force the tensioner into a position that allows assembly of the chains.

You may find that your hand isn’t strong enough to compress the piston as I’ve described above. Use a vise or channel-locks, and carefully feel your way with the wrench as you compress it. If you compress the piston with the vise when the internal pin is locked in a compressive ratchet, you will destroy your tensioner and all of this effort will be for naught if that tensioner goes into the engine. Using your fingers allows you to feel the progress of the pin along the spiral groove as it retracts.

If you try to use your fingers without thick gloves or leather pads, you may find that one or more of the pistons has sharp edges at the oil inlet end, and you’ll do a very effective job of taking a core sample out of your thumb as you twist the piston with the wrench. Please be very careful.

There’s a reason for using the stock-style grenade pins in the tensioners: it’s not possible to install the timing cover when those pins are installed because the finger rings are too big. If you use a small drill bit or a small allen wrench, you may be able to install the timing cover over the retracted and pinned tensioners. Don’t do that. Double check and triple check all three tensioners. Make sure the pins are out, that they’re extended, and the chain is tight. You should see at least a quarter to three-eighths of an inch of piston visible on each tensioner.

Now is a good time to positively slather your timing chain and sprockets with assembly lube. It will be a moment after you start or spin your engine before you get pressure to the tensioners for the first time. Use lots of assembly lube. Lots. Get it all over the chains and all over the guides and sprockets and really let it soak in and run around. I like the Lucas assembly lube that’s green and thick. The stuff is hell to wash off your hands and it feels more like glue, but I’ve never seen startup wear.

2005 SRX 3.6
56 Posts
Discussion Starter #6

If you have the harness tied out of the way, installing the main engine front cover isn’t as much of a nightmare as it looks like it might be. Make certain a new main water passage seal is installed correctly. Make certain all the mating surfaces are coated uniformly with gasket compound. Don’t torque any one area down without bringing adjacent areas down at the same time. There are two dowel pins that line up the cover, one on either side, and you’ve got both the crank and the last corner of the power steering pump to act as rough guides coming in. Don’t get gasket compound on the timing chains. There are seventeen short bolts and five long ones that need to be installed and torqued to spec. My understanding that number will be different if you have the high capacity cooling system.

Remember that my new engine cover displayed a little bit of twist or warp. This came out easily when installing the bolts around the edge, presented no real resistance, and all the edges sealed nicely. The front cover is very flexible and a little warp isn’t anything to worry about.

Install the last upper, forward, sideways power steering pump bracket bolt that goes into the left head.

Install the left and right cam timing actuator solenoid valves through the front cover. These are extremely fragile components. I had them bagged and marked for position, but I think they might be the same part number. But why risk that? I allowed them to drain for a while – they were full of used oil – and then I immersed the valve ends into fresh, clean oil for a bit, drained them again, dipped them again, and then installed them quickly while they were still dripping. Torque them to spec.

Install the water pump. Again, I think you’d be a fool not to use a new one give the amount of work going into this and the ease of access at this time. After buying the engine and some other components, I basically got the water pump and the thermostat for free with incentive gift cards.

It’s really starting to look like an engine, and a pretty one, too. If it had heavier chains and didn’t have all those concave tensioner rub and guide plates under there I suspect the hop up potential would be impressive.

Install the left and right cam position sensors. Clean them off but be careful of solvent on the plastic ends of any sensors.


Let’s fix up that dipstick tube now. Here’s the piece I cut off:

I cut a piece of stainless sheet metal about 4” to 5” long and about an inch wide. I used pliers and vise to bend it around into an L with a thick fold in the middle, and then drilled a hole to match the old cut-off piece and trimmed excess material.

Bend as necessary to get a nice, tight fit on the dipstick tube. My new bracket is partly above the cut-off edge of the old bracket, which will keep the tube from sliding upwards and out of the sump. Install the new bracket.

You know, it’s probably a good time to start thinking about keeping anything from falling into the open tops of the heads. If you cover them up now, nothing will try to jump into them. If you bolt the covers on now, sure as anything you’ll need to unbolt them again later, so let’s just set the cam covers in place for now.

Clean out the cam covers and fit new gaskets from the upper engine set. The old spark plug tube grommets just pop out if you grab them with vise grips and rock them out from the underside. Grab only the grommet material, because you can really damage the plastic covers with visegrips. The new grommets just slide into place, but be careful to get the direction right. Remember that the plug tubes will be pushing through from below, so only one way is correct. Clean the covers thoroughly before installing the new ones and the gasket, however. I used the pretty blue cam cover gaskets because they seemed a bit more robust than the red ones that came with the engine’s own gasket set. Place both cam covers in place over the heads. You can go ahead and install the oil filler cap now, too.


2005 SRX 3.6
56 Posts
Discussion Starter #7

It’s time to install the cats. The cats came out with two nuts on each pipe at the bottom end, two nuts each end at the upper end, heat shield gasket assemblies at the upper end, and pre-Cat and post-Cat EGO hookups, one each for each side. First, remembering that this is from a catastrophic head crash, let’s shake out the cats a bit.

Oh, look – here’s most of the missing valve:

I guess we’re going to be blowing smoke out of the pipes for a while when the engine finally starts up. Given the amount of oil in there, they might already be ruined. Nothing we could do about that now. If we replace the cats now, we might save a ton of work… but there’s no telling how much the oil in the headers and all the assembly lube will poison them anyway… so I’m going to put everything together and hope for the best, catalytic converter-wise.

But there’s another problem.

Here’s one of the exhaust gaskets/heat shields from the original installation. The heat shield has three layers – a thick layer of stainless formed into a gasket and bent around to form the shield, a very thin and tough layer rolled into a compression ring stuffed with steel wool, and then another thick layer riveted on the other side of the compression ring. The thin, tough layer wraps around to overlap a portion of the second thick layer, to crimp it all together.

The compression ring is toast. Aside from not being compressible twice, the inner diameter where it’s rolled and folded is cracked almost all the way around both gaskets. These things are falling apart.
Now, the upper engine gasket set has some upper cat pipe compression donuts…. But they have no integral heat shields!

These heat shields, in my humble opinion, are critical. On the left, the heat shield stands between the upper cat pipe and the starter solenoid. Solenoids aren’t known for their resistance to extreme heat. On the other side, the heat shield stands between the upper cat pipe and the crank sensor. Which is plastic. If that fails, the engine stops running. Period.

So I’m not willing to give up the heat shields. But I can’t re-use them. Trying to sandwich them along with the new compression rings together would be disaster. They’ll blow out like the extra oil filter gasket that gets missed stuck to the block after an oil change.

What to do?

How about if I remove the old compression ring, but retain the heat shield? Here’s a photo of that effort half-completed on the left side heat shield alongside one of the new compression rings. See, I’m removing the middle layer inside the hole defined by the other two layers, using a combination of tin snips and pliers. You can see the remainder of the compression ring nearer the heat shield side in the old assembly.

Here’s what it looks like with the process completed.

And here’s what it looks like assembled to the upper cat pipe along with the new compression ring.

The compression ring fits perfectly inside the hole left by the removed material of the heat shield assembly, fitting in the cat pipe’s upper end’s flange groove perfectly. To be certain this makes installing the cat pipe difficult because it means keeping the compression ring in that groove as the pipe is threaded up into place from below. It can fall out. It will shift. You do not want to start tightening this thing down with the compression ring off center, out of its groove. That will ruin the ring and you’ll have to replace it.

Here’s the same procedure applied to the right side cat pipe.

Note that this photo was taken just before the right side pipe went in, so there’s anti-seize on the threads. I won’t ever assemble exhaust studs without anti-seize, no matter what the instructions say.
The next photo shows the nuts being tightened from above on the left side cat pipe.

On the left side you’ve just got some brake lines to contend with when trying to reach down into the side of the engine bay to reach the cat pipe stud nuts. What I did was this. First, from below, lift the cat pipe into position and wedge something like a ½” drive breaker bar under it to keep it from falling back out. From above, start the nuts – they will thread easily because of the anti-seize – and pull the cat pipe up into position. Use a mirror on a stick to verify that the flange is seating nicely and that the compression ring has not shifted out of position. If it’s still in the groove, there will be little to no gap as the flange closes with the header.

Then tighten the nuts.

As I said, on the left you have more or less a straight shot down to the nuts. A couple of ½” extensions – long ones – will let you torque the nuts down.

On the right, however, the cylinder bank is far enough forward that the forward cat pipe stud aims more or less directly at the strut tower. There’s no straight shot. There’s no way to get down to it easily. On teardown, I destroyed a Craftsman ½” drive universal because the nuts were so tight. I had to wait for new tools to break that nut loose. The new tool set was a ½” drive impact wobble extension set from Sunex, part number 2504 -- $40 and change from Amazon. With ½” wobble extensions you won’t have any difficulty reaching the forward right cat pipe stud nut. Without it… you won’t ever get it loose or get it back in. Just order the wobble extensions now if you don’t already have them.

While we’re discussing tools, here are some others without which I could not have gotten this far. The magnetic telescoping retriever with an integral light is just… amazingly useful. I have half a dozen of these things now stuck to my toolboxes. That bit of twisted … stuff…. is the remains of the original left side upper cat compression gasket stuffing.

After installing and tightening the four upper cat pipe stud nuts, you can install the four lower nuts under the car. You’ll have to push and shove the exhaust assembly around, but it will push back and then slide forward onto the two cat pipes without too much trouble. These donuts are re-useable.

The post-cat EGO sensors wire up to the vehicle harness at either side of the transmission. There’s a straightforward little locking latch on each connector, plus what’s called a “CPA” – a Connector Position Assurance device – that little grey arrow that’s attached via a tether to the main harness on either side. After the post-cat EGOs are plugged into the harness, that CPA slides into the plastic connector latch assembly from the side and keeps it from working, essentially double-locking the post-cat EGO connectors in place.

Hook up the post-cat EGO pigtails. Install the CPAs.

Before you hook up the pre-cat EGOs, the harness needs to be strung around the engine. Before we do that, we want to install the heat shields.

The manual will tell you that you pulled the left side’s intermediate steering shaft to provide clearance to pull the heat shield out from below. That’s bull. It doesn’t fit out that way. Install the left side heat exhaust header shield from above. It slides down into place nicely. There are three bolts, two accessible from above and one on the side down by some of the plumbing.

Don’t get me wrong about removing the intermediate steering shaft. You have to take that out anyway during teardown for any number of reasons… but not to remove the heat shield.

As you can see, access to the upper two bolts is easy. You can get to the third one on the outside by standing in front of the vehicle and reaching down and across the engine with your left hand, starting the bolt with your thumb and index finger, the bolt pointing to vehicle right, your left. It sounds nutty, but it works very well. You can tighten that third bolt with a small 10 mm open end.

At this point you’ll likely find two little heat shields in your parts box that were removed from the left side. One of them is a little 2” square sandwich of corrugated foil that’s all razor sharp edges, and the other is a patch of flexible cardboard foil with three clips on it.

I believe the little 2” square may have been installed between the manifold and the tin heat shield on the left side to seal up the slot around the oil dipstick tube, but I couldn’t make it fit that way. There’s an open slot for the dipstick tube and a larger cutout that’s for the forward upper heat shield bolt or bolt boss. I installed it around the dipstick tube above the heat shield, catching a corner under the heat shield bolt to hold it in place. The purpose of this little filler is to keep header heat from coming up around the dipstick tube and damaging the edge of the cam cover and the water temperature sender. If it fills that gap and shields the base of the water temp sender, it will do its job.

The other flexible patch of heat shield goes under the manifold. The central clip snaps around the dipstick tube and the other two clips snap onto the edge of the left heat shield/header gasket. Its purpose is to provide heat shielding for the left anti-knock sensor against header heat. If it snaps up in there firmly and presents an obstacle between the header and the sensor, it will likewise do its job. I could not remember, however, just precisely how each of these little heat shields installed. Neither could I find photo references.

The right main heat shield installs from below. Start with the skinny end pointed up and the concave side left from just under the cat and inboard of the fenderwell. It will move up, forward, and rotate into place without too much trouble. There are again three bolts, two accessible from above and the third on the outside. On our SRX, the outer bolt was missing on tear-down and I did not replace it. I bent the shield a bit so it wouldn’t vibrate against the header and installed only the upper two, visible.

You’ll notice that I don’t have the cam cover bolts installed yet. That’s to guarantee that I won’t need to remove the covers. It’s always safest to operate with the various Murphy’s Laws in the back of your mind at every stage….


The alternator generally comes out in unit with its bracket and with one of the belt tensioners. I removed that tensioner – a single bolt – so these photos show the bracket without it. There are three bolts through from the front to the front cover and a single, smaller but longer bolt, that affixes the bracket to the side of the block, barely accessible from the wheelwell where there is no wheel and tire, or easily from under the car. Lower the assembly down into place from above and forward, slide the alternator back into its position, and catch one of the bolts from the bracket to the cover.

This is where my lack of faith in rebuilders was justified once again, because in the threaded hole in the engine cover reserved for the uppermost, rightmost alternator bracket bolt, I found the broken off remains of the bolt presumably used to affix the alternator bracket in the engine’s previous life. I will spare you that discussion. Hopefully you won’t have to contend with dealing something like that. It involves lots of WD40, a set of costly reverse spiral carbide drill bits, some screw extractors, and lots of cussing.

Torque down the four alternator bracket bolts.

From below, attach the main alternator harness ring terminal, the one covered by a boot, to the stud on the alternator. From above, install the alternator connector into its socket and snap it into place.
On the harness very near to the alternator connector there is a small right angle bracket. Bolt that to its location on the back of the alternator bracket, accessible from above. Barely. You might have to have someone with small hands do this.


2005 SRX 3.6
56 Posts
Discussion Starter #8 (Edited)

Before we can re-install the remainder of the engine harness, we need to get the main coolant pipe that runs around the right side of the engine to the thermostat housing back in place.

First, install the rigid bracket that cradles the hose, front center bottom of the oil pan. There is a single bolt under the bracket that bolts it to the front of the sump.

While you're down here, it's a good time to re-attach the brake line bracket to the left front bottom corner of the sump. Access from below.

Now jiggle and wiggle and shift the rigid portion of the hose that runs around the right side until it’s close to the thermostat housing receptacle. This big o-ring is not in the upper engine set, so I used an o-ring from a kit plus some gasket compound. Install the end of the hose with the o-ring and compound into the thermostat housing, bolt it down at the housing, and then install the bolt that fixes the rigid tube’s bracket to the right rear corner of the right head.

Install the cam cover bolts with the new rubber seal grommets from the upper engine gasket set.

It’s time to re-install the engine harness. However, my harness looked like this:

For people who try to identify the vehicles in shop backgrounds, that’s my ’97 Hurst-Lingenfelter WS6 T/A, with just a bit of its ‘vette Z06 wheel/tire/brake upgrade showing. Before the SRX, that’s the only GM product I’ve ever put up with, despite needing to remove the radiator and A/C coil to work on the ignition system, or the need to pull the rear suspension and exhaust to change the fuel pump, or the absolute impossibility of pulling the engine from above. It’s fun enough to drive I can live with those things. Barely.

This is before I started rebuilding the harness. You’ll see that most of the convolute – that split corrugated plastic tubing – has fragmented and simply fallen off the harness. This should not happen. High temperature polypropylene convolute should last the life of the vehicle, especially when it’s not exposed to sunlight. High temperature stuff should last even in an engine compartment in Texas.

This stuff didn’t.

The tape was borderline. The convolute was trash. More GM cost cutting, no doubt.

I brought this home from our harness prototyping shop.

Convolute comes in sizes from 1/8” to 2”. I brought home 3/16, ¼. 5/16, 3/8, ½, 5/8, and ¾. Of the most common size – ¼” – I grabbed more than ten feet. You always use more of it than you think you will. I picked up some high end mil-spec electrical tape for this effort too. Of all places, you can get that at Walmart. Find the most expensive electrical tape they have and read the fine print. It’s shiny, not dull, and it comes in an old-fashioned plastic tin instead of a blister on a card.

I tore down the outer layers of the harness, stripping away the desiccated and disintegrating convolute, cutting away the outer layers of tape, unsnapping the convolute terminations. If you tackle this, be careful to leave the innermost layers of tape that define the branches. There’s more precision in harness construction than you’d think, and those inner tape joints are the keys to providing the harness shape.

So after about two hours of careful de-construction and rebuild, we have this.

That’s much better. Much. A properly constructed harness doesn’t skimp on the tape, and the tape should extend all the way to the snap-on convolute terminations just behind the connectors, assuring that they don’t vibrate or get knocked off as well, taping their snaps closed. I won’t get into harness assembly here. It’s an art. There’s a whole specialized set of tools and skills involved.

Cut any remaining tie-backs and route the main branch of the engine harness with the long plastic box along the top of the right cam cover. Lay the long black plastic box on top of the cam cover and line up the three sets of slots underneath with the three white plastic camlocks that attach to the cam cover. Line up the frontmost slot with its cam, then the second, then the third, then slide all three into place by shifting the box to the left of the car.


2005 SRX 3.6
56 Posts
Discussion Starter #9
Now lay the rest of the harness around the rear of the engine and then around the left bank.
At this point I’m going to confess to some confusion. There are half a dozen ground ring lugs that attach to the engine and heads, and an extra piece of thick stuffed cardboard sound insulation that fits up under the leading edge of the windshield and behind and over the aft end of the upper intake manifold. That cardboard was a bitch to remove and I don’t think I’m going to put it back in; it was flopping loose on one side anyway. At the end – I’m jumping ahead – I’m going to have one M6 short bolt left over plus one nut that held that cardboard in place. I think I switched that M6 bolt for the stud pictured here:

… and I think that stud may have been involved with mounting the cardboard sound insulation. But… I’m not certain.

That is, I think this ring terminal pictured, which branches from the now-reinstalled right side of the injector harness, may have been bolted to a different location on the block or head in this approximate location. It’s not going to hurt anything, but be warned: for several of these ground lugs, you may find your hardware in slightly different locations, if you kept better track of teardown. This is the ground lug that branches from the harness near the alternator connectors, coming from the ECM module.

So re-attach the ground lug with the long locating tang, shown.

Moving aft, following the re-installed harness, re-attach the ground lug that bolts up to the rear right corner of the engine.

Now is a good time to re-connect the right bank’s pre-cat EGO sensor pigtail. If you haven’t already done it, push the cable and connector up into the engine compartment from below. The connector should be near the firewall, near the back right corner of the engine. Connect it to its mate in the harness.

The harness end of this connection has an integral mounting clip that snaps into a pair of holes in the rigid coolant pipe bracket that we re-installed at the back right corner of the engine, above. Feel back there for the two holes, about half an inch apart, and then shift the mated connectors down so that the clip’s pegs fit into those holes, and snap it in place.

Moving around across the back of the engine to the left rear corner, if you haven’t already done so, thread the left pre-cat EGO connection up into the engine bay from below.

Connect it to its mate in the harness near the rear left corner of the engine. Now is also a good time to snap the left injector harness branch into position and to re-install the transmission harness connector bracket.

Yes, this photo shows all three steps – the left pre-cat EGO connection, upper left in the image, the transmission harness connector bracket, right of center, and the injector branch bracket, bottom center. The transmission harness connector bracket is held in place with a single bolt, and held in orientation with a tang from the bracket inserted into a boss ahead of the bolt hole.

The left branch of the injector harness has a short black bracket with two holes and two slotted clips. The holes rest on nibs cast into the upper left edge of the left cam cover, and then the clips reach down and snap over protrusions on the head casting, fixing this branch of the harness in place. Be very careful not to allow the transmission harness connector to rest on the exhaust heat shield.

Attach the left side injector harness ground lug to the head.

Connect the water temperature sender. The harness connection for this sender is the small one with the large heat shield cylinder. Push the cylinder down completely over the temperature sender.

Now is a good time to install the dipstick.

Here’s the water temperature sender harness branch again in place. The insulated cover over the sender is visible just above the open top of the oil filter housing.

Moving back around to the right side of the engine compartment, it’s time to attach the main battery and harness ground to the engine at a boss on the head just above and behind the alternator.

Re-install the center rear engine harness bracket. There’s only one bolt. Previously this held some little cable tie loops, and is also the mounting location for the connected left pre-cat EGO connector. You can use some cable ties to fix the harness to the engine at this point. Also, move the pre-cat EGO connector right behind the engine, and plug its mounting clip pegs into the two small holes at the bottom left corner of this bracket. You can’t see the connector here. You have to do this entirely by feel. That made finding the connector to disconnect the left pre-cat EGO pigtail particularly interesting, as the manual provides absolutely no details about where to find this connector when it’s clipped down behind the left head.


2005 SRX 3.6
56 Posts
Discussion Starter #10
Attach the coolant tubing that routes to the left side of the thermostat housing.

Moving to the front of the engine, connect the left side cam position and cam timing valve solenoid connectors. Use the little black plastic clip that snaps onto the front of the camp cover. This isn’t just to cover up the harness; it also functions as the primary lock for one of the solenoid connectors. Make sure it snaps firmly and completely into place.

And plug in all the right side cam position and cam timing valve solenoid connectors. See the note above about the black plastic routing clip.

Oh, there was one more thing about the right side cat pipe stud nuts. I found that I couldn’t access the rear nut without removing a piece of the battery tray. Here it is.

This piece is held on with two bolts at the upper inboard end, and is molded in unit with another piece that bolts in elsewise. The battery tray is unnecessarily complex and it appears to be pretty much impossible to remove in total, which is why I broke this piece out. That raised inboard end blocked access to a lot of the things we’ve done at the back right corner of the engine.

Now it’s time to put it back in.

Tear down instructions are pretty clear about not touching the connectors, mounting bracket, or ground lugs for the ECM. The connectors are complex. You don’t want to be messing with their seals or with the integrity of their contacts and locks. As for the ground and bracket… reasons for that are twofold. First, if the battery is connected, you don’t want to be isolating the ECM from ground. Second, the underside of the ECM module is fairly soft and fragile plastic. It would be very, very easy to damage it. Then you’d be faced with buying, programming, and adapting a new ECM. That is basically home shop impossible because you don’t have the GM diagnostic and programming suite.

My battery was removed first off, and I’ll be careful about the ECM housing. So I pulled the ECM bracket entirely and tied back the ECM housing with its connectors intact front right.

The time has come to put back whatever you took apart. There are four bolts that affix the ECM to the bracket, if they’re loose, and three that affix the bracket to the head and cover – two front and one right side. Put that all back together, as required. There are several harness bracket and ground tabs that affix to the top and side of the bracket as well.

Now is a good time to re-install the transmission breather cap. It should be safe back there now, hidden behind the harness and heater hose.


Place the main crank pulley onto the crankshaft. You might have to tap it lightly with a plastic deadblow hammer to move it on far enough for some of the bolt’s threads to catch. The bolt itself is supposed to be single use again, but it’s a massive piece, and it doesn’t do anything except prevent the crank pulley from walking off the crank. That’s not likely to happen. I suspect the engine would run just fine without the bolt at all, but of course that’s not the right thing to do.

The right thing to do would be to replace the single use main crank pulley bolt. You should do that.
I accepted a tiny bit of risk and re-used mine, and used a little blue locktite on it just in case.

Now, the attentive observer will note at this point that we have no way of fixing crank rotation. And the attentive observer would be right. There’s no effective or practical way to use the crank rotation lock because that requires access to the starter mounting hole. The car is an automatic. The oil pan is structural and cannot be removed once the short block is installed. As for the upper end of the engine, you’d have to be a fool to try to fix rotation by sticking something into the chains or cams.

So what do to?

Here is my solution.

This is a piece of ¾” black plumbing pipe – you might have guessed I stock various sizes – about 15 to 18” long. It is bent slightly and has a notch cut into one end on the inside of the bend. The bolt is a 5/16” grade 9 3” long bent into a right angle, with the threaded end ground down into a tab about 3/16” wide. This is how it fits in the engine compartment.

It braces against the junction of the front crossmember and the frame rail, on either side, the narrowed bolt installed into a convenient slot on the outer ring of the pulley. You have to be careful to avoid crimping any brake lines with it, but it worked for both tear down and assembly, supporting any amount of torque I would care to use installing or removing the main pulley bolt. Breaking the bolt loose, for example, required a ½” drive breaker bar and my 36” pipe handle extension – which was also, as previously discussed, my custom special SRX transmission support bracket….

Torque the main crank pulley in place.

Using one of these sets – I can’t remember if this one came from HF or Oreilly’s or Amazon -- install the power steering pulley. Make absolutely certain you push the pulley on with the grooved hub side OUT, or else you will be suffering mightily for many hours, trying to figure out how to recover from such an error.

Install the water pump pulley and the two serpentine belt tensioners. You would think the two tensioners are interchangeable, but you’d be wrong. They are not. They only fit one way, both hanging approximately down. If they don’t hang down, they’re switched.

You may find that a strap wrench facilitates tightening the water pump pulley bolts easily.

Install the upper coolant tap to the block and heads. There are two bolts, an o-ring, and a 4-sided seal that seats into a groove in the coolant tap casting. Replace the two seals with the pieces from the upper engine kit. Re-attach the main right radiator hose and seat the clamp.

Install the power steering pump reservoir. There are two bolts, one large, one small, through the steel bracket to the front cover. The large bolt hole passes through the cover into the block and chances are front cover sealant has fouled the hole. If you don’t clean it out, you could jam the bolt up pretty seriously. Clean excess sealant out of the larger hole. Make sure the harness branch running behind the bracket down to the solenoid isn’t pinched.

2005 SRX 3.6
56 Posts
Discussion Starter #11
Attach both main and return lines and re-seat the clamps. At this point you can fill up the reservoir, but if you do you’re guaranteed to need to remove it again. Leave it empty for now to negate the possibility you’ll have to backtrack.


Remove the rebuilder’s cardboard plug hole plugs. Install spark plugs. Install the six coils and bolt them down. Hook up the six coils to their six separate electrical connectors. Remove and clean up any tape residue from the intake manifold interface and install a new lower intake manifold gasket from the upper engine set.

Note that it is not possible on this engine to remove or install some of the coils and plugs without removing the intake manifold assembly. While the design of the manifold assembly itself is admirable – allowing the mechanic to remove both top and bottom in one unit, blocking plug access with the intake is unforgiveable.

At this point I found this on the floor under the engine bay.

That’s a connector primary seal, specifically a seal from a Packard Delphi GT150 series 3-way female pin connector. You might ask how I know this. Well, years ago I was involved in an effort to replace this particular connector’s predecessor – a horrid little piece of automotive antiquity that required that its wires be installed into it before they could be stripped and crimped into the terminals -- in a large number of Volvo-Penta marine harnesses servicing GM small blocks. I recognized this component since I designed tooling to handle it. Anyway, I took a look through my files until I found a harness BOM for a Volvo-Penta smallblock, found the little Packard Delphi GT150 3-way, and found that it was labeled as the connector for the oil pressure sensor. I popped the oil pressure sender connector out of the oil filter housing, and found surely enough that the seal had been knocked loose. I replaced it and plugged it back in. Minor crisis averted!

Clean up the lower intake manifold lower surface.

For readers who will try to identify the vehicle in the background, the beige fender belongs to an ex-Canadian Ministry of Defense 1964 Land Rover airfield service truck with will eventually receive a pair of Isuzu disc brake locker Dana 44 rear axles, a narrowed GMC Suburban flat top knuckle front Dana 44, and an Isuzu NPR 3.9 4BD2TC mated to a Muncie 465 short hard coupled to an NP205. I’m using a reversed ’57 military helical gear NP201 with an electrically circulated oil cooler for use as both a torque splitter between the rear axles and as a 1.96:1 overdrive. There was no way I was going to stick with the leather seal Salisbury axles. Here’s a note for the bargain hunters out there: the first generation Isuzu Rodeos and Amigos have a standard width Dana 44 with simple leaf spring pads, disc brakes, and often with finned covers and lockers, and they use a standard Chevy 6-bolt pattern. And there are lots of them in self-pull junk yards. When those yards have their famous half price sales, you can pick up these axles for $130 to $180. Bargains! The second gen Rodeo axles have complex coil spring suspension brackets – and thus are harder to use in projects -- but they all have finned covers and almost all have lockers!

Set the manifold assembly in place and install the six bolts, four long and two short.

The four long central bolts are easy to place. The two short ones can only be placed remotely with a magnetic stick or flexible grippy. The rear short bolt is aligned directly below the crescent-shaped cutout in the rear left of the upper intake manifold, precisely behind and aligned with the two left long bolts. It cannot be seen when installed without a mirror. The bolt is installed only through the lower intake manifold flange about six or eight inches below and between these connectors. Torque the six bolts to specs.

Position the plastic ring that holds some of the harness gear around the intake snout. Connect the throttle body electrical connector.

Connect the big 10-way connector right front to the mating connector on the intake manifold assembly.

Install the manifold purge valve and plumbing to the right side of the intake. The forward end plugs into the manifold. The rear end receives a receptacle from the engine compartment plumbing. The barrel of the purge valve mounts to the metal clip on the side of the manifold assembly with a heavy rubber isolator. An electrical connector from the right injector harness mates with the subassembly.

Connect the PCV line from the intake manifold assembly to the tap at the rear right corner of the right cam cover. Note also this alternate view of the purge valve’s connection to compartment plumbing and its electrical connector.

The white plastic fitting on the back end of the purge valve, the primary PCV tab black plastic fitting, and the purge line connection at the front of the intake all use an integral plastic lock. You can’t just pull these connectors apart; to disassemble, find a little radial tag at the end of a curved latch that wraps around the connection. Pry at that tag with a fingernail, and the connection snaps apart easily. To re-install, just push the connector onto the ridged tubing end.


2005 SRX 3.6
56 Posts
Discussion Starter #12
Connect the fuel line. In the photo, the line with the yellow plastic label. The fuel line wraps behind the intake manifold and snaps in place over the rigid connection on the manifold. A separate safety clip hooks inside the collar of the compartment end, resting against the inside edge of the fixed end’s sealing ring, and then snaps over the exposed portion of the line.

This end sure does go together easier than it came apart! While the safety clip can be removed while the intake is installed on the engine, the internal lock in this connection uses four separate locking clips internal to the compartment end’s collar! The only way to disconnect it is to remove the intake manifold, shift and tilt the manifold to the right of the engine bay for access to the fuel connection, and then to reach into the exposed annular region of the locking collar’s end and release each of the four clips manually with a tiny screwdriver, or to use a “special tool” GM makes for this purpose. It’s not easy. The photo shows the safety clip in place on the line, approximately at the center of the image.


Install the belts. They have unique part numbers but appear on casual inspection to be identical. They’re not. The right side accessory belt that drives the alternator is very slightly longer than the A/C and power steering pump belt. Another thing here GM did right: put those ½” drive receptacles on the two idlers. The hardest part of this is making sure the belts are entirely seated on the pulley faces.

Install the front left engine appearance cover stud into the intake manifold, which holds the upper end of the forward intake manifold brace. Install the lower end of the intake manifold brace to the front cover with the large bolt, shown. Note that, like the power steering reservoir large bracket bolt, this large bolt passes through the front cover into the block. Extruded front cover sealant is likely fouling this hole. It must be cleaned out before the bolt will thread in cleanly.

Install the t-shaped coolant surge hose assembly between the radiator, upper radiator hose fitting, and coolant bottle. One end attaches at the upper right front corner of the radiator.

The other end routes all the way back to the coolant surge tank.

The center tap routes around the other plumbing near the intake snout to the connection underneath the intake snout, pointing left, behind and to the vehicle right of the appearance cover mounting stud, on the upper radiator hose fitting attached to the center top of the block and heads. Note that this 3-ended hose assembly clips into plastic holders on the radiator, right side, radiator, left side, and over the airbox.

Install the fresh air intake hose at the intake snout. Install the crankcase breaker hose from the intake hose back to the fitting at the rear left corner of the engine, routing it through the clip on the intake manifold plumbing halfway back.


I broke one of the mounting tabs off my airbox while I was climbing around in the engine bay trying to find something. There’s a cured-pliable plastic body panel epoxy made for Bondo, black, expensive, available at Autozone. It’s amazing stuff. Sticks to just about any plastic. Here you see the tab trussed up with tape. I roughed up all the surfaces on top of the tab with a dremel, cut some extruded aluminum body repair mesh to fit, and then gooped it all with the 6-minute Bondo plastic repair epoxy. Note: never buy the body panel repair extruded aluminum at auto parts stores. You’ll pay $6… $8… $10 for a little 6” square. Instead, go to a building supply place and buy a 4’ long “gutter leaf guard” for about $2.50. Same stuff!

Here is the repair and the installation. Note how the surge tank hose clips to the airbox. Also note the airbox electrical connection above the inlet.

I also broke one of the upper right cooling fan plastic support struts. When I need to repair semi-pliable plastic like this, stuff that’s generally an ABS derivative, I make up a solvent-based cement that’s a mix of the real toluene-based old-fashioned tube plastic model cement and a few drops of good liquid super glue. The stuff only has a workable life of about 20 to 30 seconds before it spontaneously crystalizes, but it will bond just about anything that’s related to styrene or ABS instantly.

If you have access to plastic solvents, do not breathe the intense vapors.



Install the intermediate steering coupling. Lift it into place from under the car and engage the telescoping upper steering shaft. Be mindful of the direction of the installation – the upper end side with the clamp threads goes up and forward and the lower end side with the threads goes inboard. Be very careful not to rotate any shafts, as there’s some feedback mechanism somewhere that can go out of whack. Install the upper clamp bolt. Pull the coupling down onto the steering rack input shaft and install the lower clamp bolt.

The lower clamp bolt can be tightened from the left front wheelwell. The upper clamp bolt must be tightened from under the car. Torque to specs.

Remove the oil fill and power steering fluid caps and install the engine cosmetic cover. Reinstall the two caps. Install the Monte Carlo brace between the two strut towers and torque down the four bolts to specs.

Replace the battery. Oh, here’s a note – the early SRX uses an oddball group size. My replacement battery was manufactured in Saudi Arabia and cost more than $200. The only apparent difference between the group 101 and another dirt cheap, common group size – 78S – appears to be the thread size on the side lugs. Replace the battery terminals and you can probably use a $90 battery. At this point I wasn’t going to mess with that because I wanted it done, but there’s the info for you.

Install coolant, oil, and power steering fluid to specs, bleed and burp as necessary.

My rebuilt engine was supposedly pre-lubed for a normal start, and as I said it was literally dripping in assembly lube. Given that I added a ton of assembly lube to the chain sets, I’m not too worried about any dry startup. Break-in instructions called for an immediate run to 2000 rpm for 20 minutes to seat the rings after oil pressure comes up.

The key was in the car when I pulled the battery, so the key was stuck until a new battery went in. So as soon as the battery was hooked up, it built fuel pressure. The engine started almost immediately. Oil pressure indicated a fraction of a second later. The engine is silent. I didn’t know what to listen for before I knew about the timing chain issues, but I remember what it sounded like before the failure, and now it’s much quieter. The chain rattle is gone.

There was so much oil from the head crash in the exhaust it acted like a mosquito fogger from the left side only for several minutes. At the end of the twenty minutes the engine was still smoking moderately from both sides, and the oil level had gone down a hair. Taking it for a drive, that smoking got worse, not better, so I knew the rings hadn’t seated. I don’t think that’s surprising. There were no special instructions for using anything other than the recommended oil for break-in – Mobil 1 – and this aluminum block probably has some nickel-silicate ceramic doped liners, and maybe the rebuild even calls for exotic coating on the ring set. Two thousand rpm, in a VVT engine that redlines at nearer seven thousand? No. It’s just not going to build enough cylinder pressure to break in.

I took it out on a rural highway and ran it through a dozen wide open throttle blasts to ludicrous speed. Interesting. The character of the car changes completely when you floor the throttle. Neither of us had ever done that before, since it’s always been the grocery getter. That little engine can roar, but then of course it is a 4-cam 4-valve hemi.

No more smoke. Not a bit. Runs perfectly. Changed the oil again and then I was all done.

2008 SRX V-6 AWD
141 Posts
Wow that's crazy.. you could have justified getting a nice 2 post lift and dropped it out the bottom ;-)

2005 SRX 3.6
56 Posts
Discussion Starter #15
Seriously, had I known the engine was toast before I started, that might have been preferable. BUT... when you drop the engine and slushbox in unit, you need to mess with re-alignment... a transmission fill ... shift linkage re-adjustments ... draining the power steering system... and half a dozen other peripheral tasks. When you build the engine up in place, you avoid all of that.

Secondly, if you search online for discussions about these timing chain failures, a complete engine loss is rare. Fallout ranges from one or two bent valves to many bent valves to seized engines, but the curve is more or less centered on "several bent valves". At which point you pull the heads, have them reworked, and then go into reassembly. Pulling the heads and finding golf-ball sized holes in pistons is uncommon. Thus, I fully expected to be sending out some heads to the machine shop, not the scrap yard. But by the time you get to that point, it's only another hour or so to finish pulling the short block. And that is a heck of a lot less work than dropping the block and transmission.

I neglected to mention in my original post that the dealer wanted $11,000+ to repair the vehicle. That is of course full list for a new engine plus labor guide totals for all of the related chores, figure $5k and $6k, respectively. Since I had to find a lot things on tear-down, I figure I spent about 50 hours total on the repair. Someone experienced with this engine bay would have taken a lot less time.


Oh! One more thing I forgot.

On the LY7 the startup oil pressure bypass valve that facilitates cold start oiling is crimped into a receptacle in the oil filter cartridge housing cover. The valve itself is the same unit used in Northstar applications, where it fits apparently in some high pressure lines and can be readily replaced. In the LY7, you have to pry the crimped-in keeper out of the cap, then replace the valve, then drive the keeper back into the cap. There are numerous stories online about LY7 owners who had startup chain noise until they replaced their bypass valve. In one case, an owner walkthrough of the replacement noted that the old valve had obviously degraded with age and wasn't functioning anymore.

Like the chains themselves, the bypass valve isn't a maintenance item... but anecdotal evidence suggests that it should be replaced every few years. So... ten years and Texas heat ... the little rubber valve was probably quite bad. So we've got a bad timing chain design, infrequent oil changes by the dealer based on the oil life monitor for 34,000 miles, and then a bad startup bypass valve as well.... all of which just aggravates the timing chain wear and tear.

I replaced the engine cap assembly with a new valve as well.

After all this work, that's a no-brainer.

The bypass valve itself is a $2 item, but I destroyed the keeper trying to remove the old valve. The replacement cap assembly, valve included, is a $22 to $50 item, readily available.

2010 CTS4 sedan
1,135 Posts
Excellent write-up and photos. Thanks for sharing these - it sounds like your SRX was worth the trouble.

2004 SRX AWD 3.6, 2006 SRX RWD 3.6, 2005 Tahoe Z71
3 Posts
Wow, man that was a pain in the butt for you it sounds like. Well, at least now it's done and done right. I just bought a 2004 SRX AWD 3.6 and it's SUPER clean. It was owned by an old lady who took great care of it. It runs now but I can hear noise in the front that I think is the timing chain. It's got 135,000 on it and I believe that it's all original. So it's OVERDUE for sure for a new chain set. Your post and pics have helped me a bunch. Thanks so much for taking the time to document everything and post it here for others, like me, who can really benefit from it all. I better get my chains replaced PRONTO before this same thing happens to my SRX too. Happy Trials Eric. Hope that car lasts you a LONG LONG time.

2005 SRX 3.6
56 Posts
Discussion Starter #19
Thank you for the kind words. We just finished a cosmetic refresh and I am about to post pics in the Epic Picture thread....

2019 XTS Luxury AWD, 2004 SRX N* AWD (gone)
2,025 Posts
Wow, just WOW! Where on earth did you get the knowledge and skill to do this!
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