[ktr-sb]

I had never heard a noise like mine was making, and not being familiar with the engine otherwise, I suspected but was not certain that the noise was from the chain, especially before the cold start rattle started. Other candidates were bearing noise from the water pump, tensioners or the fan bracket assembly. As I disassembled the engine, I checked all of these, and they were smooth and quiet. So what about the chain components?

Well, there's your problem:

And the timing chain was "stretched" and worn on the outside (new chain on left for comparison):

 

[ktr-sb]

Now time to clean up this mess:

 

[ktr-sb]

Finished product:

 

[jcobz28]

Really nice job on the write-up. You have a lot of patience! When I recently completed my timing chain job, the one thing that really threw me for a loop when putting it back together was a "missing" idler pulley. I spent 2 hrs looking for it before I decided that it never existed and I never took it off which is why I couldn't find it. Here is what is confusing to me. In the GM manual, some of the diagrams show this idler existing, yet others don't show it. In the LY7 image you posted earlier in the thread, it does show the idler.

Yet in your step-by-step photos, you never mention removing this idler, and in one of your photos (as follows) it appears that the idler does not exist on your motor either.

On my 2005 SRX, the belt just goes straight from the AC compressor to the crankshaft balancer. The belt that is on my car is SOOO tight as it is, there is no way that it could be routed up and above another idler pulley. This was another reason I came to the conclusion that my motor must not have had the idler pulley on it before I started.

So, I guess I'm posting this to get your take on the issue. Am I missing something? Or did your car not have this idler pulley on it to start with as well? And if so, then what's the deal with GM offering multiple versions of this motor, some with and some without the pulley? If yours DID have the pulley, then that means at some point before I purchased my car, someone took that pulley off and put on a shorter belt for who knows what reason.... and that I drove it that way for at least 60k miles with no noticeable consequences...

Looking forward to what you report back...

 

[tormented]

The idler pulley was dropped sometime in the middle of the 2004 model year production . I checked with the Cadillac parts counter,as my 04 doesn't have one, idler is not even available anymore.

 

[ktr-sb]

Really nice job on the write-up. You have a lot of patience!

lolz. Not what my ex-wife and ex-girlfriends think.

I spent 2 hrs looking for it before I decided that it never existed and I never took it off which is why I couldn't find it.

Yeah, now you know why I take a million pictures. It's a habit I developed in my line of work. I do forensic analysis of car crashes, and the more pictures I get of a vehicle or crash scene the happier I am.

In the LY7 image you posted earlier in the thread, it does show the idler.

View attachment 83413

Yeah, that picture is of the "global" motor, a press release image done at the very beginning of production. Global motors are used in a variety of applications, so they may have individual changes depending on the specific vehicle it goes into. I would suspect that the next post is absolutely right, a running change dropped it from production.

Yet in your step-by-step photos, you never mention removing this idler, and in one of your photos (as follows) it appears that the idler does not exist on your motor either.

My engine does not have this pulley, and I did note that difference when I saw those press release pics. I have seen other timing chain threads where there were pictures of the disassembled engine and the idler pulley was present, so I chalked that up to it being an engine installed in a CTS or it not having the heavy duty cooling like mine. I apologize for the oversight in not mentioning it.

I really do appreciate the note. This is exactly why we have a forum like this - the chit-chat is nice, but what I really enjoy is the thought of helping someone out and giving them more comfort in doing it themselves.

 

[ktr-sb]

OK, now for seal replacement. Remove the crank and cam phaser oil control valve seals:

Then insert the four cam phaser control valve seals, making sure the side with the four notches facing down (toward the rear or inside of the engine). No lubrication or sealant necessary:

Then, get a suitable tool and tap in with a hammer. Go slow and check progress to make sure it is going in straight. I used this OEM brand from 'Vatozone for free:

Repeat for the crank seal.

 

[ktr-sb]

Now for the chain installation. There are three chains. The primary chain is driven by the crank gear, and drives the two intermediate, or idler, sprockets. The secondary chains are driven by the intermediate sprockets, and drive the camshafts. The chains are stacked - closest to the block is the left secondary chain, then the primary chain, then the right secondary chain. So the chains will be installed in that order - left secondary, primary, right secondary.

Install the chain in two Stages, each stage involving a different crank position. (Yes, you will be turning the crank with the right secondary chain off, but you won't bend valves.) Stage 1 consists of installing 1) the crank gear, 2) the left intermediate (or idler) sprocket with chain, 3) the primary chain, 4) the left secondary guides and tensioner, and 5) the primary guides and tensioner. Then on Stage 2 you move the left camshafts and crank and install the right secondary chain, guides and tensioner.

So first, mark and install the crank gear (I used orange paint since it is a different color than the other marks, and I love these Testor's paint sticks):

Make sure the flats on the ends of the left cams are pointing up, and the flats on the right cams at an angle. (Using the factory tool on the right cams will later allow you to turn the engine to get it to the Stage 2 position.):

Now, line up the crank so that the tooth with the dot lines up with the dot cast into the oil pump housing. The marked crank gear tooth should be at about the 5 o'clock position.

Look at one of the secondary chains. You will see it has 3 white marked links. The two white links that are separated by seven unpainted links go around the cam phasers. The third white link goes on the tooth that can be seen through the hole on the intermediate sprocket.

Wrap the secondary chain around the left intermediate sprocket - you will know which it is because it has the marks facing out, and the roller sprocket teeth close to the block. The hole in intermediate sprocket will be at about the 7 o'clock position to get all three marks to line up (first pic is without the chain for clarity).

Now bolt the intermediate sprocket to the block (43 ft-lbs), and line up the white links with the cam phaser sprocket teeth marked "L" - they have circles marked as well so there is no mistaking them:

Now bolt on the right intermediate sprocket. Install the primary chain with the yellow marks lining up on the dot for the crank gear, the arrow at 11 o'clock on the left intermediate sprocket, and the dot at 10 o'clock on the right intermediate sprocket.

 

[ktr-sb]

Now install the left secondary chain guides and tensioner, and the primary guides and tensioner. The left secondary tensioner is the one with the plunger that fell out when you pulled it off. Of course, you are using all new parts, but you will need to compress the plunger. I forgot to take pics of this process with the new one, but here is the two-piece tool and old plunger. The end of the plunger that pushes on the chain shoe goes into the socket-like piece, and the rod-like piece of the tool fits into the end of the plunger that fits into the tensioner. The socket holds the plunger, and the rod is used to push and twist so that the plunger resets.

Anyway, the rest of installing guides and tensioners is pretty self-explanatory - just don't let the chain go out of time. Here are some pics of the installed components (they're such good pics I couldn't leave them off the thread:

 

[ktr-sb]

Now for Stage 2. I didn't do this, but now would be a good time to extend the mark on the secondary teeth of the right intermediate sprocket all the way to the center of the gear, to the bolt. This will help confirm that the right secondary chain is properly placed.

Make sure that all marks line up, then remove the camshaft retaining tools from the camshaft ends, and rotate the crankshaft so that the dot on the crank gear is pointing at roughly 9 o'clock. If you did not use the special tools, the right camshafts may have rotated to where the right intake cam mark (the triangle) is at about 12 o'clock and the right exhaust cam mark (the other triangle) is at about 9 o'clock. If this happened, you will have resistance when you try to rotate the crank.

No sweat, just rotate the cams about 90 degrees by the cast hexes - use a 20mm wrench or crescent wrench. The valve spring pressure will "pop" the cam over to where it needs to be, just watch your fingers and be ready for the jolt. You will end up with the intake mark pointing at about 2 o'clock and the exhaust mark at about 12 o'clock.

It's a two handed process, and you might want a helper. I didn't, so no pics of this process.

At Stage 2 you should see this:

The yellow link on the crank gear will just have released from the tooth with the dot at about 9 o'clock:

The yellow link on the left intermediate sprocket will line up with the triangle at about 4 o'clock:

The yellow link on the right intermediate sprocket will have just released from the tooth with the dot at about 2 o'clock:

Now install the right secondary chain, lining up all three marks (triangles on cam phasers, painted tooth with dot on intermediate sprocket:

Now install the guides and the tensioner, and you should now have a properly timed engine:

 

[ktr-sb]

OK, let's get the cover back on.

First, pull the timing chain tensioner pins. Forgetting to do this will make everything you are about to do a waste of time.

Next, make sure the gasket surface between the block and the timing cover is very clean and free of old sealant. Spend some time here, it is well worth it.

Put in a new water pump seal:

Install guide pins:

Get some Permatex Ultra Grey. Note my homemade tube roller. Run a bead where the old one was. The factory says it ought to be a 3 mm bead - don't skimp, but don't go crazy:

Carefully guide cover onto pins and into place. Pull the bolts out of the box where you taped on the timing cover diagram (you did that, didn't you?) and run the bolts in hand snug but not tight. I used these two tools:

Let it sit for an hour then tighten the bolts to final tightness. You know you put the right amount of sealant on when you get beads like this:

 

[ktr-sb]

Install the cam phaser solenoids:

Install the cam cover spark plug tube seals:

 

[ktr-sb]

OK, finished up the evening with cam covers back on with plugs and coils.

First, install the spark plug tube seal guide tool:

Make sure you put a dollop of Ultra Grey on the seams between the timing cover and the head where the cam cover sits (there are four spots), and install the cam covers, following the cross pattern in your manual:

Plugs and coils and I'm spent:

 

[ktr-sb]

Well, I got it back together. I loaded this thread onto my laptop in the garage, and scrolled backwards to reassemble - literally the reverse of disassembly.

Didn't lose a single bolt, and only one of the bolt insulators. Spent a lot of time cleaning and making sure all the lines and wires were running in the right places. Replaced the air filter - it was pretty dirty and the bottom was dripping with oil on the intake side.

Tomorrow when it's daylight I will fill with oil and water and see how it goes.

 

[G32006SRX]

Awesome job...can't wait to hear the results...

 

[ktr-sb]

Well, after a little drama with the radiator (tool slipped, holed it, epoxied) it's running. Boy, I forgot how much I like these engines. Took it for a little spin, 22 mpg average on highways with hills. Thanks for following along. I have tons of pics and insights I haven't posted, so if you are in a jam, PM me.

 

[JimmyH]

We edited your posts as requested. Please make sure we did what you asked.

 

[ktr-sb]

We edited your posts as requested. Please make sure we did what you asked.

Yes, thanks!

 

[JimmyH]

glad to help

 

[nascarnation]

Beautiful work and beautiful documentation. Take a bow, you are THE MAN.