Nathen13

I have a 2010 cobalt XFE. It has the 2.4l ecotec. Just today the check engine light came on, so i took it to a shop to have the code read. The code said p003 if i remember correctly, the mechanic said its a misfire on cylinder 3.

I took my car to a buddys house, and we pulled all of the spark plugs and checked the gaps. They were all 0.04-0.045. The manual says 0.035, so we gaped them correctly. Anyways, when we pulled cylinder 3, there was a lot of oil on the spark plug, and it could be seen in the cylinder. We reset the code, thinking possibly the gaps of the spark plugs were the problem.

I drove around for 10-15 minutes, and the light came back on. This car has approx. 95k miles on it and this is the first problem I've had.

Just a few days ago i changed the oil and cartridge filter. I put in castrol gtx semi synthetic and a bosch premium filter. My dad thinks because I switched to synthetic that that may be the problem because it's thinner. I'm not sure if I think that. Anyways I've been researching and I've also found that it could be the valve cover gasket leaking, which I don't think would be too tough to fix.

Any suggestions or insight would be appreciated!

Thanks, Nathen

tomj77

iTrader: (2)

if u have oil in cylinder 3, ur rings are most likely finished. ur gonna need a rebuild, at least on that cylinder. im sure if u do a compression test that will confirm that. and synthetic oil is not ur problem, synthetic oil is what u should be running in the car. and when oil heats up its all the same. its when its cold that 10w, 5w, 0w is different.

Nathen13

So this most likely isn't a DIY job? I was hoping it was just the valve cover leaking into the cylinder..

Edit: Also would it be safe to drive my car like this, or should I just let it sit until I can get it fixed?

tomj77

iTrader: (2)

ps. if ur friend and ur dad knew about the oil in the cylinder and didn't know right away that the rings were most likely blown and to do a compression test, probably not the best people to take advice from on what the problem might be.

KMO43

well a valve cover leak will not ever put oil into the combustion chamber it will leak either outside or into the spark plug hole. If you have a #3 misfire try moving that coil to the #4 hole and if the miss moves it's the coil. If it's oil you have to do a compression check to see if it's leaking but it won't usually miss unless there is a lot of oil in the cylinder

SR Tech

iTrader: (2)

From what I'm getting from your post it sounds like the valve cover is leaking oil into the coil boot hole and causing your misfire.

As stated above, try swapping the coil with another cylinder and see if the misfire follows it. If it does replace that coil and the valve cover gasket.

tomj77

iTrader: (2)

I believe he said misfire can come from a bad coil. and the oil in cylinder could be from bad valve cover gasket and leaking oil into the cylinder. that would be easy to tell, just take out the coil from cylinder 3 and if its leaking oil ull see it if u shine a light in there. hope that's ur issue. if it would be from valve cover. do a compression test though that will tell u what u need to know. if its the rings u will have low compression on cylinder 3

Snail_SS

iTrader: (3)

A misfire could be alot of problems but doing a compression test is the best thing to do. If you wanna start with the simple things and see if it fixes I guess changing plugs and coils is a good start, but in your case yeah rings are prob gone and you need to rebuild engine .also bad valves will give you a misfire. Also your incorrect gaps are what of might have caused the problem in the first place.

SR Tech

iTrader: (2)

Stop scaring the op with "bad rings, and motor rebuild" and all that nonsense. There is no way there would be raw oil in the actual combustion chamber unless it fell in after he took the spark plug out. And there's a very small chance of the oil getting past the spark plug, after leaking from the valve cover.

I believe he is referring to the tunnel in the head that the coil boot sits in, not the actual combustion chamber as your are all referring to. If the coil boot is submerged in oil it will swell the rubber and cause your misfire.

Op I would put money on it being a bad ignition coil cause by the leaking valve cover, if everything is as I'm stating it above. Replace valve cover gasket and coil and be done with it.

tomj77

iTrader: (2)

it could be seen in the cylinder. if he doesn't mean cylinder then he should say it right. if he does mean cylinder like we said, do a compression test.

Celestial739

If the plug well was full of oil and he simply didn't notice before he pulled the plug, all he's going to say is oil on plug and oil in cylinder.. from what I gather it sounds like a valve cover gasket leak, but as stated above a compression test will easily rule out rings

But I highly doubt 10-15 mins of driving could fill the plug well enough to throw the light again, could have a bad coil too

tomj77

iTrader: (2)

possible. but yes compression test.