Spark Plugs Covered in Oil

[JoeNooch]

Hello,

I have a 2010 2LT, completely stock, ~97,500 miles (daily driver.) I replaced the spark plugs this past weekend and received quite the surprise. (3) of the (6) spark plugs were completely covered in oil. Like they seriously looked like they were dunked in oil. The car runs well, no rough idles or anything like that, no blue smoke when the car starts up, 20 mpg still.

I suspect this is an issue with the valve seals, but I was curious if anyone else has run into this and what the is/was? Thanks.

[Night trained]

What was covered in oil, the spark plug galley full and plug porcelain part? If so you need valve cover gaskets and clean the coil insulators...

[JoeNooch]

Just the threaded parts and tip were in oil, not the porcelain.

[Elite Engineering]

First thing is how much oil has it been using between changes? (LLT's and LFX's are know oil users, so always check every week or so as there is no low oil level warning light until 2014).


Then, remove your throttle body, and reach your finger inside the opening of the intake manifold into the cast in "sump". I suspect it is full and then take a few minutes to pull your top plenum cover and take some pictures. Bet it is full of oil.


Valve guides at your mileage are most likely worn far out of acceptable spec, so more oil is probably entering there as well. W/out a good GDI design effective Catch Can an system (not just any, the Elite E2 and E2-X is the most effective period and designed just for your engine and all GDI engines) , the intake valves build large deposits on them, and as these are hard abrasive deposits, every time your valves open and close they draw this hard abrasive stuff up into the guides.


Do what were suggesting, take pictures, and post back if what you find is what we describe.


If so, at this stage (have you had the timing chain replaced yet? if not, do so ASAP) you will need to remove the intake manifold and perform a manual intake valve cleaning, then clean all oil from the IM and install the correct oil separating can system and avoid this in the future. Guides probably should be replace in the heads along with seals as they wear as well when valves become unstable with guide wear.


Try the cheaper way first and see.

[JoeNooch]

Very interesting.

I'm aware of the oil issues with the LLT; I change every 4k, but start checking levels around 2k and add oil as needed. Only use Mobil 1 5-30.

I will open everything up this weekend and take a few pictures. Thanks.

[TooCool5]

Originally Posted by JoeNooch

Very interesting.

I'm aware of the oil issues with the LLT; I change every 4k, but start checking levels around 2k and add oil as needed. Only use Mobil 1 5-30.

I will open everything up this weekend and take a few pictures. Thanks.

These plugs would not fire covered in oil. There is probably an upper
valve cover leak and they were coated by the pool of oil as you
unscrewed them out.

[Ventmaster]

Were the three covered in oil all on the oil filler neck/filter side?

If so, I'm betting you've just had a bit of spillage and they got covered (those holes are pretty deep) as you threaded them out.

Am I right about location?

[JoeNooch]

Originally Posted by Ventmaster

Am I right about location?

No, the plugs with oil were on both sides.

[Night trained]

time for some new valve seals

[rtcat600man]

I changed my spark plugs today. Replaced with stock AC Delco. 88k on the original set. My back two plugs came out wet with oil on the threads and casing. The tips were dry and normal. So the oil is pooling up in the hole not in the head. I do not believe this is from valve seals going bad. I am going to look into where the oil is coming from as I find this interesting.

[L99CAMA2011]

My LS3 cylinder #5 does this after the cam install. Not as bad though. I also noticed it does this if the plug wasn't seated properly. Make sure you torque your plugs evenly.

[rtcat600man]

Originally Posted by L99CAMA2011

My LS3 cylinder #5 does this after the cam install. Not as bad though. I also noticed it does this if the plug wasn't seated properly. Make sure you torque your plugs evenly.

Thanks, but what I don't understand with your comment is, even if the plug is not torqued properly, where is the oil coming from. Not like this is a 2-stroke engine where gas and oil are sent into the combustion chamber. The only thing getting into the chamber is fuel and air. So where is the oil coming from that is sitting in the ignition coil chamber?

[jamalkhaffaf]

Hey everyone,

lets start by stating i am pretty neob with car issues but you start somewhere! Anyway took my car to chevy and they explained exact issue above. My spark plugs were covered in oil and the O-rings were worn out! So changing spark plugs and O-rings and i guess some cleanup that cost my wallet 916$$$... that was a slap in the face. Just the labor was 507$.

But they did mentioned that this is a common issue that they start seeing in Camaro that is 6 to 7 years old. My car is 2010 RS 2LT with 72k millage. Pretty low millage but i guess age do matter.

What got me upset is that chevy claimed that this is not part of the regular maintenance of the car and its considered parts failure. But i still do believe that this could of been avoided if Chevy included it in the 50k maintenance or basically after 5+ years of owning the car.

They also mentioned something about Cylinder tubing, if that leaks then they will have to change the Cylinders which will cost anywhere between 3k to 4k ... now I am wondering if its worth keeping the car for another 3 years or should I start thinking of getting rid of it?!!

[DonM]

Originally Posted by Elite Engineering

First thing is how much oil has it been using between changes? (LLT's and LFX's are know oil users, so always check every week or so as there is no low oil level warning light until 2014).

My car is a '13 and it has the low oil level indicator in the DIC