Chevrolet Cruze Forums banner

Pinched valve cover gasket, burning oil

5968 Views 12 Replies 4 Participants Last post by  OEMplusCC
Hi All,

Hoping to get some opinions on my recent issue.

So I had oil leak from camshaft (valve) cover gasket and I decided to replace it. Just the gasket, I know PCVs are common to fail but mine was still good so I only ordered a brand new genuine AC Delco gasket.
I replaced it as shown by DIYs online and torqued everything to proper specs and in the recommended sequence.
I took it for drive, two miles in I noticed rough idle so I stopped and opened the hood. I noticed there was oil coming out from the top right corner, under the "PCV circle" area. I must have pinched gasket during installation in that area. I turned around and headed home, keeping low RPM. But then the car started smoking from tail pipe, it was heavy and there was lot of smoke. Obviously, I was burning oil like crazy. When I got home I pulled all 4 spark plugs and sure enough there was oil in all 4 cylinders.


My question, could a pinched(or just bad) valve cover gasket cause oil to go down to cylinders?

OR

Could have something else blown inside the engine because of bad valve cover gasket?

I just ordered new gasket and I will replace it again, however I'm afraid the first pinched gasket could have caused some internal damage. I cant see how the oil could have gone to cylinder just because of bad valve cover gasket.

Thanks!
1 - 13 of 13 Posts

· Registered
Joined
·
22 Posts
Discussion Starter · #3 ·
Yes, I cleaned surface very well. I have not removed valve cover yet but I'm sure gasket either slipped or pinched in the top right corner. I can see oil leaking from that corner. The question is, how did that cause oil to go down to all cylinders?
 

· Registered
Joined
·
20 Posts

· Registered
Joined
·
354 Posts
Unfortunately the valve cover seal will not cause oil to enter the piston.
I think you have a 2nd issue not diagnosed.

I've folded a couple of valve cover seals, always been able to re-seat it.
Only symptoms was spraying the engine bay with oil mist and a slight lean condition at idle.

My bet is PCV valve in the intake manifold. If you replaced it recently it can take a month for all the oil to get pushed threw the intake track.
 

· Registered
Joined
·
22 Posts
Discussion Starter · #7 ·
Unfortunately the valve cover seal will not cause oil to enter the piston.
I think you have a 2nd issue not diagnosed.

I've folded a couple of valve cover seals, always been able to re-seat it.
Only symptoms was spraying the engine bay with oil mist and a slight lean condition at idle.

My bet is PCV valve in the intake manifold. If you replaced it recently it can take a month for all the oil to get pushed threw the intake track.
Do you think replacing intake manifold now or at least cleaning the old one can help with oil going to cylinders?
 

· Premium Member
Joined
·
5,470 Posts
Woe there!

OP? Are you saying there was oil in the spark plug wells upon disassembly after the leakage was noted?
Or, are you saying oil was in the cylinders and burned onto the firing end of the plug.

If oil was in the wells, that just means the seal was leaking there as well.......clean and replace 'o' ring as needed.
I might add, clean any oil out of the bolt holes that hold the cover in place. Failure to do so will often result in a 'hydrolock' condition as you try to tighten the cover bolts. Since a liquid cannot be compressed, tightening the bolts will often result in the threads tearing out of the head.
To clean out the holes spray brake clean (wear eye protection) into each hole and either blow out the hole(s) with compressed air or a by blowing through a vacuum line directed into each hole.

I'm not going to talk about oil on the plug firing ends because I doubt if that was the case.

Keep in touch,

Rob
 

· Registered
Joined
·
20 Posts
If oil was in the wells, that just means the seal was leaking there as well.......clean and replace 'o' ring as needed.
I had oil in my spark plugs holes and I believe it was due to the PCV failure in the intake manifold. Happened to me with a brand new, properly torqued valve cover assembly.

Sent from my SM-G955U using Tapatalk
 

· Registered
Joined
·
22 Posts
Discussion Starter · #11 ·
Woe there!

OP? Are you saying there was oil in the spark plug wells upon disassembly after the leakage was noted?
Or, are you saying oil was in the cylinders and burned onto the firing end of the plug.

If oil was in the wells, that just means the seal was leaking there as well.......clean and replace 'o' ring as needed.
I might add, clean any oil out of the bolt holes that hold the cover in place. Failure to do so will often result in a 'hydrolock' condition as you try to tighten the cover bolts. Since a liquid cannot be compressed, tightening the bolts will often result in the threads tearing out of the head.
To clean out the holes spray brake clean (wear eye protection) into each hole and either blow out the hole(s) with compressed air or a by blowing through a vacuum line directed into each hole.

I'm not going to talk about oil on the plug firing ends because I doubt if that was the case.

Keep in touch,

Rob
Spark plug wells are dry as well as ignition coils. Oil is inside the cylinders. When I removed spark plugs all of the were wet with oil. I also fed borescope camera through each spark plug hole and saw oil on top of each piston (explains all the smoke from tailpipe).
I think its the PCV as others mentioned. It was probably week already and I "finished it" by introducing a vacuum leak with pinched valve cover gasket. That's my current theory based on information from here.

Interesting thing is that pcv nipple is still in the intake manifold. However I cant say if its torn or something, I can just see it from the top.
 

· Registered
Joined
·
354 Posts
If the PCV nipple is still there we can rule that out.
How much oil is pooling in front of the throttle body?
Turbo is really the only suspect. How many miles on the current turbo?
 

· Registered
Joined
·
22 Posts
Discussion Starter · #13 · (Edited)
If the PCV nipple is still there we can rule that out.
How much oil is pooling in front of the throttle body?
Turbo is really the only suspect. How many miles on the current turbo?
I found some oil residue under throttle body but I have not removed the pipe to inspect inside.

I do have an update:
So I ended up getting new gasket. I also decided to replace PCV pipe (corrugated hose) because I blew in it from both side and I did not get much resistance from any direction.

Replaced everything, started the car. It was smoking but after a while ~10minutes all smoke cleared. Removed spark plugs and cleaned them up and also checked for correct gap. There appears to be no more oil in the cylinder, and no stored codes. We are all good now.

There was (and probably) is still some oil in pipes going to intercooler(because of bad GM design) which might have backed out when the gasket was leaking. We might need to upgrade to bigger car soon but If i'm going to keep this car for longer I will install V2 intake manifold fix kit.
 
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top