Help ! Oil in spark plug slot - ZR-1 Net Registry Forums

dlgeary · 09-15-2006

I need some help from the experts!

I am a new owner of a 94 ZR1 (6 Months) and last night when I was changing spark plugs, the #5 cyl spark plug was covered with oil on the outside. I pulled the boot and oil dripped out of it and when I pulled the plug it was tight and looked the same at the other ones but with oil on the outside. All other plugs were fine.

The car has been running fine. I suspected the crank case vent that enters the plennem just above this plug, and checked the PCV valves but they were fine. There are no visible signs of oil.

Where do I start looking?
Don

09-15-2006

Don, has the engine been apart at all?

How high up the boot was the oil?

dlgeary · 09-15-2006

I do not know if the engine has been apart, it only has 24k miles but had several previous owners.

The oil was about half way up the boot.

I have not started it since changing the plug but no more oil leaked into the slot while I had it apart.

09-15-2006

I'm thinking the oil is comming from the seal inbetween the cam cover and the cylinder head. This is not a place oil usually gravitates to if it is leaking from someplace else.

dlgeary · 09-15-2006

That's what I am afraid of too. Do you think that the first thing I need to do is take the plennum off to see what is going on in there. That is no small task in itself.

09-15-2006

It's fairly simple to remove the plenum.
http://www.pnwzr1.net/LT5_tear_down.htm

I would suggest running the motor with out that psark plug plugged into the head and see if you have any seepage from the seal.

Jim Jones · 09-16-2006

Actually with the help of Jeff's site, I took the plenum off without too much trouble. I printed off everything related to the LT5 teardown from his site and put it in a three-ring binder. It was VERY helpful, as I am a complete novice mechanic (that was my first major undertaking, and the car still runs!)

Good Luck!

Jim

Hotrod · 09-16-2006

FYI: There is an "O" ring seal between the the heads and the valve (cam) covers. When the seal goes bad, oil from the cams, works its way up around the spark plug (outside) and wets things down with oil.

dlgeary · 09-16-2006

OK, Thanks guys.
Jeff, these instructions are great. I will print them off and do some investigating. Looks like the only way to change spark plug wires is to take the plenum off anyways.

I have a full shop manual but sometimes those aren't descriptive enough.

dlgeary · 09-18-2006

OK, you guys are NOT going to believe this but...

I had this idea to put some high temp Peratex Ultra Black sealant on the small lip inside the spark plug slot where the cam cover meets the head. There was a small lip because the cam cover was a little larger than the rest of the spark plug hole. I let it dry and cure for 24 hours then drove the car to our club picnic about 20 miles from home.

I checked it when I got home and no oil. I am sure this is a temporary fix but at least it works until I have time to take the plenum and cam cover off to fix it right.

Thanks again for your help. Jeff that website is awesome.

09-15-2006	#1
dlgeary Join Date: Sep 2006 Location: Jeannette, PA Posts: 6	Help ! Oil in spark plug slot I need some help from the experts! I am a new owner of a 94 ZR1 (6 Months) and last night when I was changing spark plugs, the #5 cyl spark plug was covered with oil on the outside. I pulled the boot and oil dripped out of it and when I pulled the plug it was tight and looked the same at the other ones but with oil on the outside. All other plugs were fine. The car has been running fine. I suspected the crank case vent that enters the plennem just above this plug, and checked the PCV valves but they were fine. There are no visible signs of oil. Where do I start looking? Don

09-15-2006	#2
Jeffvette Guest Posts: n/a	Re: Help ! Oil in spark plug slot Don, has the engine been apart at all? How high up the boot was the oil?

09-15-2006	#3
dlgeary Join Date: Sep 2006 Location: Jeannette, PA Posts: 6	Re: Help ! Oil in spark plug slot I do not know if the engine has been apart, it only has 24k miles but had several previous owners. The oil was about half way up the boot. I have not started it since changing the plug but no more oil leaked into the slot while I had it apart.

09-15-2006	#4
Jeffvette Guest Posts: n/a	Re: Help ! Oil in spark plug slot I'm thinking the oil is comming from the seal inbetween the cam cover and the cylinder head. This is not a place oil usually gravitates to if it is leaking from someplace else.

09-15-2006	#6
Jeffvette Guest Posts: n/a	Re: Help ! Oil in spark plug slot It's fairly simple to remove the plenum. http://www.pnwzr1.net/LT5_tear_down.htm I would suggest running the motor with out that psark plug plugged into the head and see if you have any seepage from the seal.

09-15-2006	#5
dlgeary Join Date: Sep 2006 Location: Jeannette, PA Posts: 6	Re: Help ! Oil in spark plug slot That's what I am afraid of too. Do you think that the first thing I need to do is take the plennum off to see what is going on in there. That is no small task in itself.

09-16-2006	#7
Jim Jones Join Date: Apr 2005 Location: I'm in a constant state of euphoria in the Z! Posts: 237	Re: Help ! Oil in spark plug slot Actually with the help of Jeff's site, I took the plenum off without too much trouble. I printed off everything related to the LT5 teardown from his site and put it in a three-ring binder. It was VERY helpful, as I am a complete novice mechanic (that was my first major undertaking, and the car still runs!) Good Luck! Jim __________________ Life's too short to be unhappy! [IMG]http://i4.photobucket.com/albums/y128/koolaid117/Montage.gif[/IMG]

09-16-2006	#8
Hotrod Join Date: Sep 2005 Posts: 9	Re: Help ! Oil in spark plug slot FYI: There is an "O" ring seal between the the heads and the valve (cam) covers. When the seal goes bad, oil from the cams, works its way up around the spark plug (outside) and wets things down with oil.

09-16-2006	#9
dlgeary Join Date: Sep 2006 Location: Jeannette, PA Posts: 6	Re: Help ! Oil in spark plug slot OK, Thanks guys. Jeff, these instructions are great. I will print them off and do some investigating. Looks like the only way to change spark plug wires is to take the plenum off anyways. I have a full shop manual but sometimes those aren't descriptive enough.

09-18-2006	#10
dlgeary Join Date: Sep 2006 Location: Jeannette, PA Posts: 6	Re: Help ! Oil in spark plug slot OK, you guys are NOT going to believe this but... I had this idea to put some high temp Peratex Ultra Black sealant on the small lip inside the spark plug slot where the cam cover meets the head. There was a small lip because the cam cover was a little larger than the rest of the spark plug hole. I let it dry and cure for 24 hours then drove the car to our club picnic about 20 miles from home. I checked it when I got home and no oil. I am sure this is a temporary fix but at least it works until I have time to take the plenum and cam cover off to fix it right. Thanks again for your help. Jeff that website is awesome.