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Valve Cover Gasket PREMATURE Failure - any guesses why?
Hey all,
Figured I would put this question to the forum to see what people thought.
Basic background: I've an '04 TL 6MT purchased from the original owner about a year ago. Now has 173,000 miles on it. Overall kept in pretty great shape, but of course with some things to be caught up on which I've bit by bit been doing (LCA bushings, struts). The original owner appears to only have brought the vehicle to the local Acura dealership for all scheduled and unscheduled maintenance, and I got the dealership to share a spreadsheet of all the services performed on the vehicle that spans 160,000 miles of the vehicles history.
Currently my valve cover gaskets are leaking pretty badly and have had some degree of leak since I bought the car at about 162,000 miles, something that I know will need to be addressed in the not too distant future but livable for now. For the mileage, not a complete surprise but...the original owner had the valve cover gaskets replaced already not that long ago! From the records I have from the dealership where he always took the car, he had them replaced less than 2 years ago (May 2017) at 155,000 miles approximately. So based on that information and the time from when I bought the car, they started to leak less than 10,000 miles and 1 year after replacement.
Is there any reason others can think of that would cause such premature valve cover gasket failure? I am planning to replace the gaskets myself within this year once I again have access to a good garage setup (seems like not too hard a job, so will consider it a learning opportunity), but I want to make sure that it doesn't kill another set of gaskets again prematurely. I want to make sure there isn't some underlying issue that would cause this to happen (and potentially cause it to happen again if gaskets are replaced).
the only way you will find out is when you take it apart to look for the damage...
is it flipped upside down? is it off center? is it pinched on one side? is the mating surface not level/smooth???
noone will know until you take it apart to inspect it.
the only way you will find out is when you take it apart to look for the damage...
is it flipped upside down? is it off center? is it pinched on one side? is the mating surface not level/smooth???
noone will know until you take it apart to inspect it.
So, get going!
Yeah...in the end that will be the final answer to the question!
I actually was just looking through the service records further and saw that this is actually the SECOND time this is happening. The valve cover gaskets were first replaced after the valves were adjusted in 2015/126,000 miles. And then again replaced in 2017/155,000 miles just for the gaskets (assumed they must have been failing at that time, no other maintenance mentioned). Just seems weird!
I'm just crossing my fingers that the dealership botched the job...twice...and there is no more mystery to it than that!
I agree with @justnspace, an installation failure is most likely, another thing to check is to see if your PCV is fully operational, if it isn't it can cause pressurization of the engine covers and gaskets, and one of the most likely sources for leaks is the valve covers.
I agree with @justnspace, an installation failure is most likely, another thing to check is to see if your PCV is fully operational, if it isn't it can cause pressurization of the engine covers and gaskets, and one of the most likely sources for leaks is the valve covers.
Thank you, that is really useful to know, will check this next to see if there is an issue!
This has happened to me before. I used an OEM valve cover gasket and I torqued down all valve cover bolts properly using an in-lb torque wrench. I cleaned the head's mating surface super clean also. It started leaking within the year. What you need to do is to smear a light layer of hondabond on the gasket itself, this WORKS and it has been over 20k miles ago now. Just a light layer of hondabond, don't load a ton of it.
Hmmmm. Strange that they've been replaced twice and still leaking. Did the original owner verify the install? (e.g. ask to see the old gaskets?). Are you sure that both gaskets are leaking?
Not really sure how even a novice Acura tech could botch an install, much less on both gaskets.
OP, the torque spec for those valve cover bolts is only 8.8 ft-lbs. The bolts have built in stops, which if reached before the torque spec, should be respected. The bolts are extremely easy to shear. It's possible that the shop sheared 1 or more bolts and didn't bother to replace them....
Hmmmm. Strange that they've been replaced twice and still leaking. Did the original owner verify the install? (e.g. ask to see the old gaskets?). Are you sure that both gaskets are leaking?
Not really sure how even a novice Acura tech could botch an install, much less on both gaskets.
OP, the torque spec for those valve cover bolts is only 8.8 ft-lbs. The bolts have built in stops, which if reached before the torque spec, should be respected. The bolts are extremely easy to shear. It's possible that the shop sheared 1 or more bolts and didn't bother to replace them....
At this point I can confirm that the front valve cover is leaking on the front side, seems to favor the left side (when looking at engine). Need to take a better look at both covers and from all sides but wasn't able to do so today, just lifted the hood and snapped a quick picture. Stay tuned for better photos!
I'm interested to see if one of the bolts ends up being shorn once I get around to taking off the covers, that is a good reminder to be careful with the torque specs!
This has happened to me before. I used an OEM valve cover gasket and I torqued down all valve cover bolts properly using an in-lb torque wrench. I cleaned the head's mating surface super clean also. It started leaking within the year. What you need to do is to smear a light layer of hondabond on the gasket itself, this WORKS and it has been over 20k miles ago now. Just a light layer of hondabond, don't load a ton of it.
I'm making note of Hondabond, thanks! I've a project or two with the vehicle I want to do first before the gaskets are the goal, but once I change them out I don't want to have to mess with them again (not for a long time at least)
I managed just a quick photo today as it was icy raining and I was in work parking lot, so wasn't looking to get hands too dirty at the time. Will need to get a better look at both valve covers from all sides to see where exactly the leaks are (and aren't) once I've better weather and daylight on my side.
The most obvious leak (and this may be the only one for all I know) is front cover left side (pictured). I worry if this is going to kill my alternator prematurely as looks like it is getting dripped on by the oil leak, if anyone has any thoughts on that possibility please share!
Haven't checked the PCV valve yet, but just ordered a new one all the same as once I check I'll want to just replace if it is showing any sign of failure. With 173,000 miles currently and hoping to go many more, figuring I'll replace some things before outright failure just to make the most of the effort.
Front valve cover (left side), if not clearly recognized
That could be a spark plug o-ring leak on #4, maybe also #5. Pull the coils for 4 and 5 and see if there is oil either one of them. You can also put a socket on that valve cover bolt and see if it's loose. Use a 1/4" drive, nothing larger. Best if you have 1/4" drive torque wrench.
When you remove the valve cover, make certain the lip is flat/straight as some tightened the bolts too much and distort the lip.
The bolts bottom out, but the gasket seal isn't tight.
That could be a spark plug o-ring leak on #4, maybe also #5. Pull the coils for 4 and 5 and see if there is oil either one of them. You can also put a socket on that valve cover bolt and see if it's loose. Use a 1/4" drive, nothing larger. Best if you have 1/4" drive torque wrench.
That can be easily verified by pulling the coil packs and just shining a flash light down the spark plug tube and look for a small pool of oil. But from experience, it is the valve cover because it is flowing down to the top of the front cat. If you let it go long enough, you'll smell burned oil every time you drive.
from the picture OP took, it seem the valve cover gasket never got replaced. I mean who would replace the gasket and not doing a quick wipe down of the valve cover?
when install valve cover try to limited contact between head surface and gasket, it easily can be roll over and create a leaks. When tighten the bolt the procedure is tighten everything from center outward, I drive the bolt down with my fingers on a pattern and tighten them again with a 1/2" ratchet until it snug (very light pressure). DO NOT tighten and the gasket will distort and cause leak.
Another tip is don't be cheap when replace valve cover gasket... I always replace the set of rubber grommet washers and bolts since the bolt over the years experience extreme temperature swing (especially the front bank).
OP you can see my valve cover gasket replacement in my red TL progress thread.
from the picture OP took, it seem the valve cover gasket never got replaced. I mean who would replace the gasket and not doing a quick wipe down of the valve cover?
when install valve cover try to limited contact between head surface and gasket, it easily can be roll over and create a leaks. When tighten the bolt the procedure is tighten everything from center outward, I drive the bolt down with my fingers on a pattern and tighten them again with a 1/2" ratchet until it snug (very light pressure). DO NOT tighten and the gasket will distort and cause leak.
Another tip is don't be cheap when replace valve cover gasket... I always replace the set of rubber grommet washers and bolts since the bolt over the years experience extreme temperature swing (especially the front bank).
OP you can see my valve cover gasket replacement in my red TL progress thread.
The dealership the previous owner brought the car to definitely charged him (just under $500) based on the records I have, so be pretty bad if they didn't! When I get organized to pull the covers off and replace all the gaskets, very much plan to replace everything (rather do it all correctly once and be done, not try and save $20 or similar and regret it).
Originally Posted by t-rd
That can be easily verified by pulling the coil packs and just shining a flash light down the spark plug tube and look for a small pool of oil. But from experience, it is the valve cover because it is flowing down to the top of the front cat. If you let it go long enough, you'll smell burned oil every time you drive.
Have definitely smelled some oil burning, so valve cover is sounding more and more likely. Not every time, probably just for the longer drives? I seldom am in the car more than 20 minutes at a time during the average week, so maybe not long enough to get the oil dripping
Originally Posted by Turbonut
When you remove the valve cover, make certain the lip is flat/straight as some tightened the bolts too much and distort the lip.
The bolts bottom out, but the gasket seal isn't tight.
Originally Posted by nfnsquared
That could be a spark plug o-ring leak on #4, maybe also #5. Pull the coils for 4 and 5 and see if there is oil either one of them. You can also put a socket on that valve cover bolt and see if it's loose. Use a 1/4" drive, nothing larger. Best if you have 1/4" drive torque wrench.
Thanks all for the helpful info, very much appreciated! I will be replacing the radiator this weekend at a buddy's (man, I wish I had a garage at my current place...) so will have a lot more opportunity to check a few of these suggestions out, see what can be learned! My friend is a lot more knowledgeable than I am with these things (what happens when you've owned something like 7 high mileage BMWs over the years), so we should be able to figure a few things out. Will snap a few pictures and share what we learn
you will be surprise how much shortcut dealer took if you are not checking, this is why I always double check their works... even tho mine never did some thing like charge for a service and not doing it.
Could this be a leaking PCV valve? It looks like the grit was washed away immediately under it.
Hmmmm good point! I hadn't really noticed before now, but there really is a very distinct line in the oil mess right at the valve....
I've a new PCV valve to put in this weekend, so will see if the old one sounds bad. My understanding is that the valves should have a pretty distinct and easy to make rattle when shook to let you know the valve is freely moving; a quiet valve means something is probably stuck in one position and thus not doing its job. I'll also wipe down the oily mess along the gasket after the valve is replaced to see where the leak first emerges from and whether the new valve seems to slow it down.
Well, was able to swap out my radiator today and while I was under the hood replaced the PCV valve. The old one definitely sounded very muted when shook when compared to the new one, so likely was pretty sludged up on the inside. From the previous owner's service records it had never previously been replaced, so hoping that this may have played a role in the oil leak around the valve cover. Wasn't able to go any deeper into this issue today (checking the spark plug tubes for evidence of oil leak) as the radiator replacement was the main goal, so that step probably will be a "next weekend" thing.
From getting a better look around the valve cover gaskets in the daylight and with more time on my hands (though still with the intake manifold on, so not a perfect view), I would still say the only valve cover leak is in that Front Left section. I wiped the surface around the gasket clean as well, so will try to get a better idea of where the leak originates from once I've put a few miles on.
Figured I'd provide an update for anybody looking for info in the future
I am thinking the PCV valve was the issue (or the bulk of it). After replacing the PCV valve I've not noticed any new oil grime in the last 1000+ miles or smelled any burning oil. Granted, summer in Texas is coming soon so that will be the true test if any oil is leaking out from the valve gasket or elsewhere...but so far so good!
If it truly was the PCV valve all along, this is only one more thing to justify my aversion to dealerships. Previous owner prematurely replacing valve cover gaskets due to a leak to the tune of $550 at the dealer, and it might have been the $15 PCV valve in the end...
I don't get the concept of doing a valve cover job and skipping out on a $15 part. When I did the valve cover I replaced my PVC (which had 20k miles on it).
I don't get the concept of doing a valve cover job and skipping out on a $15 part. When I did the valve cover I replaced my PVC (which had 20k miles on it).
Neither do I! It is both cheap and dead simple to replace, not really much justification in ignoring it
As best as I can tell, the PCV valve was either original or hadn't been replaced in a while. I have the dealership records for the car that previous owner pretty much religiously brought it to for 14 years, no mention of PCV valve replacement anywhere. When I replaced it, the valve was pretty sludged up and almost no movement inside it.
02-18-2019, 03:05 PM
Valve Cover Gasket PREMATURE Failure - any guesses why?
