andy-gts

I changed the plugs today. all plugs were a light tan, just beautiful!!
but in plug hole 6 and 7 ( the 2 middle ones on the right bank) I had a meniscus of oil below each plug.

this engine has the oil control system that greg placed and the engine has seen 9000 miles with 10 wot runs at the texas mile. no issues ,just thougt it was time as the plugs are 2 yrs old.

does this imply failing cam cover gasket? I havent taken the belly pan off and looked from below. or does this portend something else, no other oil anywhere else....

what do you guys think??.

thanks for your thoughts...

WallyP

For that much oil after that much service, I would work hard to ignore it...

ptuomov

Photo?

By the way, congratulations for actually using the car!

andy-gts

ok....I will ignore....just thought I would ask, thanks wally.

ptuomov...yea I have actually put on 11 k since getting it sept 2011 from greg , I changed to wr5dc plugs after about 2k miles. has been a blast. I use it for taking longer trips. purrs like a kitten. . still some hot start issues but easily put up with.

Bill Ball

So, oil down around the base of the plug? The rubber donuts around the plug hole in the cam cover are leaking.

andy-gts

thanks bill,

thats what I was looking for! I never have taken this stuff apart before.

is this something that will suddenly break loose or just a pesky leak to fix in the winter!

thanks bill

andy

GregBBRD

If the oil is on the outside of the spark plug and just a film, check again, at your next spark plug change. If there is a puddle of oil down there, around the outside, monitor. We pull out the spark plug connectors and find virtually the entire cavity full, frequently. I've never been much of an "up-seller", so I don't "sell" people on a valve cover reseal, unless the gaskets are pouring on the outside. The oil on the outside of the spark plugs doesn't ever seem to hurt anything.

BC

How do you feel about a little dab-l-do-ya of sealant on those donuts? Maybe a thin coat of hylomar?

MGW-Fla

Good words of reassurance to hear........ I remember my initial "Oh Sheet!" reaction when I saw some oil around the outside of two of my plugs when I changed them earlier this year.

andy-gts

Great! thanks everyone.

Avar928

Spark plug seals are leaking. The driver side bank on my car had two cylinders leaking, one with a slight leak and the other had submerged the plug completely. I did a refresh on both sides and no leaks since.

I believe there's a possibility of the oil impeding the electrical connection by increasing the resistance and harming performance. I would dive in, valve cover job isn't that bad especially on the driver side.

FredR

Andy,

I don't think oil is being pressure fed into that cavity- just gravity or more likely capiliary action. Just keep a eye on it as others have said.

auzivision

I think this is an oh **** moment many 928 owners have experienced first hand only to learn later that it's not catastrophic. Being that the dual cams consume most of the over head real estate, the plugs are virtually surrounded by oil that is being held back by a small piece a rubber.

rgs944

I had the same thing at last spark plug change. My cam covers also leaked a little down to the exhaust at high rpm. I went back over and snuged all bolts down a little and no more leaking to the outside. I have not taken the plugs back out again to see if the inner donuts sealed better but I am sure it helped.

Bill Ball

I did my cam cover seals a while back due to oil leaks on the original cover edge seals dripping down on the exhaust enough to create a oil burning smell. The new spark plug hole donuts were fit dry, just as the factory did, as those had never leaked and the new ones fit snugly on the cover (no need to glue them on, unlike the edge seal). Not long after I finished this I started noticing oil in 2 or 3 of the spark plug holes. I was a bit disappointed. I added the tiny compression washer/spacers that the factory installed in 87 and 88, but were not on my 89 originally. That should have hellp but it didn't. One of the holes gets quite a bit of oil in it. I can feel the donuts inside the holes - they can get displaced during installation, so that is worth checking carefully right after you lay the cover down, especially if you do this with the engine in the car, since maneuvering the cover over obstacles can knock them off. They were apparently in the proper location then and seem to be now, so the leaks were unexpected. Everytime I remove the affected spark plugs, a bolus of oil goes down into the cylinder and I get quite a smokey start up after that. Also, you want to clean the bottom of the hole as well as the spark plug so that the electrical grounding of the plug to the head is not affected. Irritating, but I've put up with it for quite a while. I plan on replacing the original rub blocks on the cam chain tensioner soon and will have at the cover seal and donuts again, probably with a bit of goop on the donuts this time.

Andy - you could try adding the tiny washers if they were not installed. That may help to close any gap, although it didn't help in my case, even adding them to ALL the cover bolts, not just the bottom edge.

Note that the cover bolts "bottom" hard on a shoulder. So, be careful if you decide to tighten them as they hit the target torque (only 7 ft lb) suddenly and don't tolerate being twisted further.