I'm doing a spark plug change on a 2007 G35 AT 2WD (engine is VQ35HR). Replaced the spark plugs on the driver side, no problem. Now on the passenger side, the first plug has oil in the well, up 1/4" on the spark plug insulator. Take the plug out, looks ok on the firing side. Pretty much the same as the other 3 plugs that I took out.

Car has 160,000 miles and runs fine. Idles well. I checked the oil pressure this morning (harbor freight gauge). It was 20 psi after warming up a few minutes. Idle was around 650.

What is the fix? Is this a valve cover gasket issue? Or something worse?

 

The entire valve cover is the usually prescribed remedy, the well tube gaskets are sealed into the valve cover and are technically non-replaceable. However they can be drilled out and replaced, you can google search for threads on the process, it's fairly time consuming and the replacement well tube seals are not an exact fit which requires the use of permatex ultra grey RTV sealant to fill the gap between the size of the OEM and the replacement seals.

You can find new aftermarket valve covers for VERY reasonable prices now so most folks just go that route.

It's also perfectly viable to just remove your factory valve covers, replace the primary gasket and RTV the front couple of spots as shown in the FSM, and apply RTV to the existing well tube seals to seal them up better. This has been done MANY times successfully, your choice.

Personally I would just drill out the existing factory VC's and replace the well tube seals but I already have the right size hole saws and a jig made to center the holesaw because I've done it 3 times now on various cars. You can make your own centering jig by cutting the correct diameter with a holesaw into a 2x4 piece of wood, then put that jig onto the larger size holesaw to cut the VC and it stays centered. Your choice.

Or you can just set a maintenance interval to pull the spark plug that leaking to get rid of the oil buildup (basically just draining it into the cylinder, or you might just swab the oil out with a rag instead), you might only need to pull one plug every couple thousand miles and you can normally do that band-aid for a VERY VERY long time.

 

Common on some Toyotas as well... Not sure how much oil it really takes to kill the coil. On the Toyos anyway.. completely filled and no one was the wiser other than discovery at spark plug change.

 

Thanks for such a detailed answer.

I cleaned out the oil completely out of that one spark plug hole (a thin clean rag wrapped around a long screw driver). Replaced the remaining 3 plugs. No oil found in the last two.

Pulled the battery cable to reset everything and went for a drive. Wow what a difference. Drove it for over 30 minutes, stop and go, 80 mph on the freeway. Prior to this, I was getting the P0024 code. Did an oil change and then I got both P0014 and P0024 codes within 5 minutes of driving.

I did quite a bit of troubleshooting on those codes. The retarder magnets and solenoids all were the correct resistance. Replaced all the cam shaft position sensors (four of them).

Anyway I happy that the car is not throwing codes - at least for 30 minutes... Thanks again for the help. Great forum as well.

 

If it does toss those codes again do the exhaust valve control timing recalibration steps from the FSM, section EC - Engine Controls. It's pretty simple.

 

As you probably guessed, the P0014 and P0024 codes showed up again.

Does the battery need to disconnected to clear the code before running the recalibration? Or can it be done with a code showing? Also is it ok to put a foot on the brake?

 

The engine needs to be running and all those other conditions need to be met from that little snipped I posted.

I believe you can set the parking brake but NOT have your foot on the brake. At least that's how I do it and it works on the rev-up, should be the same on the HR since it uses the same type of exhaust cam retard.

Make sure to use a timer to verify you're getting the full 20 seconds.