So I decided to change my spark plugs today and I had a nasty surprise. There was a considerable amount of oil and sludge on the plugs/in the spark plug hole. I also noticed that the gap was enormous, the biggest size I can measure is 0.040 and they were bigger than that!

What is causing oil to leak into this area? Head gasket? I should mention that I changed the valve cover gasket last summer so I don't think the leak is from there.

Here is a picture:




Thanks

 

I just realized what happened here. In the fall I had a leaking valve cover gasket and I changed it out. I have not changed the spark plugs since then so the oil I found today is just residue from before I changed the valve cover gasket.

 

the gasket in the middle goes out all the time. its very common. even if you just replaced it

 

I'm going to clean out the area and the new plugs and run it for a few days. Then I'll take a look to see if it is indeed leaking or what was in there was just residue from the old valve cover gasket.

Question about the huge gap though, what kind of effects would a large spark plug gap have on performance?

 

pretty much everything. you need a large enough gap to provide a good enough ignition, but a small enough gap to allow the spark to transfer efficiently.

if you are running stock coils, the largest gap youll want to run is .030 inches, but most people settle on .028 inches. some others, like myself, upgrade to fsi coils. we run gaps of about .040 inches

 

The new plugs I put in are gapped to 0.032, I was under the impression this was the recommended gap for non-chipped cars and the BKR6E plugs and that 0.028 was for chipped cars?

 

Yes, you are correct, and I have an ATW chipped at 28 gap.

 

May I ask what "the gasket in the middle" means? I have a 4 cyl 1.8t.

I have oil on plug #3, quite a lot. A little bit on other plugs. This post is encouraging, if I can solve the problem with a valve cover gasket. I was fearing head gasket leak but I have no other symptoms.

Cautious optimism!

 

The reference is to the valve cover gasket which surrounds the spark plug holes. The other valve cover gasket seals the perimeter of the valve cover. If you buy a valve cover gasket kit, it will come with both gaskets.

 

Thank you. I'll get the gasket set and seal it up.

But first, I need to clean my PCV system thoroughly. The spark plug oil leak and one other oil leak started when I replaced the "T" PCV system hose at the back of the engine which had a big tear in it. Now, with the PCV system tight, I suspect blow by as the cause of the oil leaks.

John