: Northstar Valvetrain Clatter



Jeff198
01-24-08, 07:40 PM
Greetings all! I recently purchased a '99 Seville from a small used car dealor, who bought the car at auction and had the head gaskets replaced in order to sell it. Car sounded fine when I picked it up. Drove it home about 80 miles in heavy rain, so didn't notice any engine noise, but next day noticed noise from front cylinder head area, especially on the driver's side. Tech at local garage used to work for a Cadillac dealor changed oil w/additive. No difference. He said engine is no good. Drove it home (ran & still runs perfect, btw), took oil cap off and looked in, no oil circulating. Replaced oil filter in case clogged, but no difference. Thought might be oil pump even though oil light not on, so towed to Caddy dealor. They tested pump and it is fine. Said it would cost too much to find cause of no oil to cylinder heads & suggest new engine. Lower part of engine may still be getting oil; not noisy or knocking. Just the valvetrain area on top. Sounds like a diesel!

Could something have been left out when the head gasket job was performed? Does anyone know of anything that would prevent oil circulation to the top of the engine, but not the bottom?

Thanks in advance for your help!

Jeff

AJxtcman
01-24-08, 10:05 PM
um
look at this
http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/129385-front-valvetrain-clacking.html

Jeff198
01-25-08, 02:37 AM
Thanks for replying. I checked your link. While the cam and associated parts are the reason for the noise, the underlying problem is that there is no or little oil getting to the cylinder heads. I compared the '99 to my '97. I took the oil filler cap off my '97 and could see plenty of oil gushing across the closest valve, etc. But on the '99 there was no oil circulating. I remember reading something somewhere about plugs in the cylinder head and wonder if one of them came out or was missing, what would the effect be? Would it affect oil flow?

Thanks,

Jeff

AJxtcman
01-25-08, 08:45 AM
Thanks for replying. I checked your link. While the cam and associated parts are the reason for the noise, the underlying problem is that there is no or little oil getting to the cylinder heads. I compared the '99 to my '97. I took the oil filler cap off my '97 and could see plenty of oil gushing across the closest valve, etc. But on the '99 there was no oil circulating. I remember reading something somewhere about plugs in the cylinder head and wonder if one of them came out or was missing, what would the effect be? Would it affect oil flow?

Thanks,

Jeff

I know about a plug in the block.

Jeff198
02-06-08, 01:15 AM
Well, I asked the Caddy dealor to take valve cover off to check for problems. Found nothing, but even if they had, they said valve train is gone due to lack of oil. Even if I had cylinder heads replaced, the problem of no oil to the heads may remain. I'm going in couple days to pay the bill and drive it home. If it doesn't make it, I'll call AAA. Heads are a total loss anyway. Guess my only option is to look for a used engine. Dealor quoted $6100 to put in a used engine, $9500 to put in a new engine. I just don't want to spend that much on a "99. My other option is to sell it as is.

Thanks for your help,

Jeff

tateos
02-06-08, 06:24 PM
I would think the worst case scenario would be new cams and lifters - maybe also chains. Not cheap, but the cylinder heads would not be a total loss. You are correct that you would need to find the base problem before investing in new parts

dkozloski
02-07-08, 02:27 PM
One collateral problem with cam and valve train failures is that an awful lot of very hard metal grindings get introduced into the lubricating system. It's like running your engine on grinding compound. The filter catches a lot of it but some still bypasses on cold starts. This hard stuff gets imbedded in bearing inserts and it really raises hell with things.

tateos
02-07-08, 02:53 PM
Good point dkozloski

srx2005
02-10-08, 02:19 PM
First, attempt to return the car and get your money back from the used car dealer; or, negoitate an arrangement for him to pay for the repairs. Tell him what your next step will be (see below) if you can't come to a satisfactory agreement.

If you don't have any success, do some research and organize/prepare documentation (e.g. sales documentation; service orders from your dealership explaining the problem and cost of repair; timeline document showing date/time of - purchase, when problem first occurred, attempts to repair, etc.). Then, send your documentation to the local/state consumer protection agency and the local district attorney. My guess is that there is fraud in the form of lack of disclosure (depending on your local and state laws) involved with this transaction since the problem occurred within hours and a few miles of your purchase.

Here are some things to research and include in your documenation:
> Do you know for sure that the headgaskets were replaced (e.g. do you have a copy of the paperwork from the mechanic)?
> If the work was performed, talk to the mechanic/garage that performed the repair. If they don't cooperate, explain what you are planning to do and how they will be involved.

AJxtcman
02-10-08, 03:26 PM
One collateral problem with cam and valve train failures is that an awful lot of very hard metal grindings get introduced into the lubricating system. It's like running your engine on grinding compound. The filter catches a lot of it but some still bypasses on cold starts. This hard stuff gets imbedded in bearing inserts and it really raises hell with things.

The valve cover catches a lot of it:eek:
What is it that you say? The valve cover.
I was so surprised when I saw a new Valve Cover for the first time and found the inside to be smooth and clean. Then I found the rough surface of the inside of the valve cover scrapped of and the it was magnetic.

Jeff198
02-13-08, 09:30 PM
Here's what I've learned so far. First, the cost of repair is unknown because the Cadillac dealer says they would have to remove the engine & tear it apart to find out why oil is not getting to the valve train. Thus, they say I might as well just replace the engine.

I hadn't decided what to do, so I paid for services rendered to date and drove the car home. Before leaving the dealer I added 4 qts. of oil. Started the car. It was very loud at first, but eventually quieted down some. Even though I was told that oil pressure tested OK, I decided I had nothing to lose and added 6 more qts. of oil to perform the procedure to clear the pressure relief valve. Did not make a difference but here is what I discovered. Looked in through the oil filler hole and noticed slight bubbling oil near the closest top head bolt and slightly around the nearest valve. Revved the engine a little and a sheet of oil squirted out from behind the far left cam bearing cap (I think that's what it's called).

What I suspect is that oil is getting to the cylinder head, but is being blocked from entering the camshaft and as oil flow increased it squirted out the side. As I understand from what I've read, the camshaft is hollow and oil flows through it. What I don't understand is how exactly the oil passes through into the camshaft. I have Cadillac service manuals for the car, but cannot find any good diagrams or details about this part of the heads. Is there anything that could be misaligned that could block the flow of oil? Or do you think I am way off base? Any suggestions?

Submariner409
02-13-08, 09:57 PM
Oil is ported from the block to the gallery that supplies the hydraulic lash adjusters and also from that gallery to the individual cam bearings. The follower sled (pre-'00) or roller (post-'00) and valve tip area is lubricated by directed splash. There's plenty of oil vapor and droplets flying around in the valve cover area to do the job (as in nearly every engine design, pushrod OHV included).

The bubbling oil near a head bolt is not good. That's a compression leak.

If a cam bearing cap is loose enough for oil to squirt out the side, that's not good, either.

I don't believe the cam is hollow or is an oil carrier.

Something is very, very fishy here. eWill3 might be able to offer some insight.

Jeff198
02-14-08, 02:41 AM
Here's what I've learned so far. First, the cost of repair is unknown because the Cadillac dealer says they would have to remove the engine & tear it apart to find out why oil is not getting to the valve train. Thus, they say I might as well just replace the engine.

I hadn't decided what to do, so I paid for services rendered to date and drove the car home. Before leaving the dealer I added 4 qts. of oil. Started the car. It was very loud at first, but eventually quieted down some. Even though I was told that oil pressure tested OK, I decided I had nothing to lose and added 6 more qts. of oil to perform the procedure to clear the pressure relief valve. Did not make a difference but here is what I discovered. Looked in through the oil filler hole and noticed slight bubbling oil near the closest top head bolt and slightly around the nearest valve. Revved the engine a little and a sheet of oil squirted out from behind the far left cam bearing cap (I think that's what it's called).

What I suspect is that oil is getting to the cylinder head, but is being blocked from entering the camshaft and as oil flow increased it squirted out the side. As I understand from what I've read, the camshaft is hollow and oil flows through it. What I don't understand is how exactly the oil passes through into the camshaft. I have Cadillac service manuals for the car, but cannot find any good diagrams or details about this part of the heads. Is there anything that could be misaligned that could block the flow of oil? Or do you think I am way off base? Any suggestions?

Jeff198
02-14-08, 02:54 AM
Thanks Submariner. It gives me something to think about. I am in the process of trying to get info from the repair shop that did the head gaskets to try to find out if anything was done to the heads before installation, or even if they used the original heads! I suppose if the heads are no good I could have them replaced, but I don't know if a second head job would work out ok.

Thanks again!

Jeff198
03-17-08, 01:30 AM
Update: I decided to take the front valve cover off to inspect inside. Using a stethoscope I have verified that only the front was making all the noise Everything looked fine so I turned the engine over a couple times. Oil seemed to flow ok around lifters and cams. I oiled all parts and reinstalled the cover. It wasn't easy to remove and reinstall either! Took it for a test drive. Valve train was loud at first, but got quiet and by the time I returned home, it sounded normal except for a light tick! Much better than before. I am going to drive it now to see if noise returns.

chubbyranger
03-17-08, 06:24 AM
By any chance did yours sound like this?

http://members.cox.net/chubbyranger/clatter.wav

2.7M .wav file. Not recommended for dial up.

Jeff198
04-13-08, 03:02 AM
Sorry I did not check back sooner, but, yes, mine sounded a lot like that. Usually, when I first start it after sitting for awhile it is slightly louder, but quiets down after a minutes. I have been driving it to work and so far, so good. The only thing I can figure out is that some debris got into the oil pan when they replaced the front head gasket, and some of it caused the oil relief valve to stick slightly open, and after a couple oil/filter changes with additives, it disolved or cleared itself. The "18 quarts of oil procedure" sited earlier in the posting may have helped to clear it too. But, to tell you the truth, I don't really know for sure why it got better!

chubbyranger
04-13-08, 08:14 AM
Glad yours worked itself out. Mine turned out to be two bad exhaust cams and the beginnings of HGs.

Cultoo Suntory
08-15-08, 01:04 AM
I didn't want to make a new post for this since it is related to this thread, my car sounds like this when cold.

http://www.box.net/shared/c93hegpxn4

143k dial up friendly.

It is gone when warm...occasionally a small tic..when I drive out of the garage first thing in the am and let off the gas (low speed) it clatters like a diesel as the engine speed decreases. The above recording was made after it sat for about 7 hours.

I have read many of the posts about valvetrain noise and carbon rap, but I thought some might like to hear what I hear.

Submariner409
08-15-08, 11:20 AM
Cultoo....Have you performed a couple of WOT (wide open throttle) runs ?? If not do a search in this forum for WOT and cold carbon rap. If you don't understand the process, c'mon back......

Make sure the engine has the proper quantity (halfway up the dipstick hashmark) of 5W-30 brand name oil and a clean ACDelco or WIX oil filter.

Cultoo Suntory
08-15-08, 02:48 PM
Thanks for your reply Submariner409.
I have had the car a year now, and the last three months or so I haven't done any WOT, and the former drive to work was only 3 mins...now it's about 20. It has only recently gotten to the point that I noticed it. I did just do a 2500 mile round trip a few weeks ago, but there were no WOT's, I guess I was driving in relaxed mode. I am not sure of the brand of filter..just that it is white. I guess I have some more research ahead of me.
Thank you again for your advice. I will report back with any progress

tateos
08-15-08, 03:58 PM
It sounds like the valve clatter increases when you let off the throttle, which also means the oil pressure goes down. Could be worn lifters with excessive leakdown rate, lazy oil pump, maybe plugged oil filter or the oil pressure regulator on the fritz?

Submariner409
08-16-08, 06:10 PM
Hmmmmm......The hydraulic lash adjusters are static, so unless one or two has dirt chips holding the oil inlet check disc off its seat, they're hard to "wear out". The oil pump/relief/bypass valve question can be answered by rigging a mechanical oil pressure gauge to the sending switch with a pipe T, either temporary or, if you're adventurous, permanently.

An oil change with a WIX 51522 filter and your favorite proper grade oil will raise oil pressure (hot) by 3 - 5 psi. The WIX units have more filter material and more pleats so they cause less pressure drop across the media. (Same for their air filters, too.......)

tateos
08-19-08, 02:20 PM
Hmmmmm......The hydraulic lash adjusters are static, so unless one or two has dirt chips holding the oil inlet check disc off its seat, they're hard to "wear out". The oil pump/relief/bypass valve question can be answered by rigging a mechanical oil pressure gauge to the sending switch with a pipe T, either temporary or, if you're adventurous, permanently.

An oil change with a WIX 51522 filter and your favorite proper grade oil will raise oil pressure (hot) by 3 - 5 psi. The WIX units have more filter material and more pleats so they cause less pressure drop across the media. (Same for their air filters, too.......)

Sub - valve if the valve lifter surface riding on the cam lobe is worn, or if the cam lobe itself is worn, to the point that the lash adjuster travel is exceeded, the valvetrain will be noisy. If the valve lifter leakdown rate is excessive, the valvetrain will be noisy

Submariner409
08-19-08, 05:11 PM
tateos, True....I'm coming in from the point that a 2003 would have to be in really bad condition to have that type of valve clatter, BUT no matter how you cut it, it's not right......Going on your post #22, there are technically no "lifters" to wear out and therefore no lifter face riding on the cam: it's a roller follower. Not to say the cam lobe(s) couldn't be worn, but hard to do in a roller setup.

cultoo, here's basically what your valvetrain looks like so you know where we are in this diagnosis.......the head has been cut in half, so you're looking at the polished end of a cut camshaft, maybe the exhaust cam. As you can see, the only moving parts are the cam follower and valve stem. The hydraulic lash adjuster, which preloads the cam follower, is static and is oil pressure fed by the small D-shaped passage. Your car has the illustrated later model roller cam follower which allowed, in part, a change to 5W-30 lube oil.

tateos
08-20-08, 12:28 PM
Sorry Sub - I thought we were still talking about a '97, but it looks like now we are on an '03 now

Cultoo Suntory
08-20-08, 09:29 PM
Thanks again for your advice, I will look for a wix filter and throw it on. This weekend I will be on the highway and will be sure to give it plenty of WOTs. I do have the fsm's, the suggestion of checking the oil pressure did interest me as well.

Cultoo Suntory
08-25-08, 12:11 AM
Many WOT's on the way to my destination, although they were limited to the final part of the trip. When I arrived my step-father came up and without hearing aids told me "it sounds like a bad tappet" Now after the trip home, just steady highway driving, the car was very quiet at home...even in the 1500 rpm range where you really hear the rattles. I did change the oil filter before I left. Due to time restraints actually a napa gold which I understand is made my wix, it was taller than the one I took off a powerflo. I shall see how it sounds throughout the week. I thank you again for your advice.