Oil Leak Question??
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
Likes: 21
From: Denville NJ
Oil Leak Question??
I have an oil leak on my stock '86 that just popped up this weekend. I know it's not the valve cover gaskets because I replaced them 6 months ago. Also, when they were leaking I could see the oil running down the head on each side, now the heads look pretty dry. The leak drips oil right on the driver's side pre-cat / "Y" pipe vicinity which is where I can see it burning off. Any ideas what this could be? I'm hoping not the rear main seal 
Thanks for any help or ideas. BTW, everything is pretty much still OEM factory and she has 107,000 miles on the clock.
Thanks for any help or ideas. BTW, everything is pretty much still OEM factory and she has 107,000 miles on the clock.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Charles, double check the drivers side valve cover again. That sounds like where it would be leaking from if the oil is getting on the precat. As suggested, tighten the bolts down some. You might want to use a flashlight and look all over that area and even under the car. Use some deagreaser to clean, so the leak will become more visible.
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
Likes: 21
From: Denville NJ
Thanks for the replies guys, I will definately re torque the valve cover nuts and see if that's where the leak is coming from. You have no idea how much I hope that a little snugging will do the trick 
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Originally Posted by CG77VETTE
I have an oil leak on my stock '86 that just popped up this weekend. I know it's not the valve cover gaskets because I replaced them 6 months ago.
I also changed to a 1 piece Fel-Pro rubber oil pan gasket. It is so nice to have an old car that doesn't leak.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Those FelPro PermaSeal gaskets are the *****...
A very strong light and a flexi mirror will likely reveal the source of the oil leak.
You might also check behing the intake base for wetness and check the oil temp gauge as the diaphram can develope a leak over time.
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
Likes: 21
From: Denville NJ
Originally Posted by Frizlefrak
Did you use cork or rubber? If you used cork, change them to Fel-Pro rubber and forget about any future leaks. I swear by them. With cork, I swore at them.
I also changed to a 1 piece Fel-Pro rubber oil pan gasket. It is so nice to have an old car that doesn't leak.
I also changed to a 1 piece Fel-Pro rubber oil pan gasket. It is so nice to have an old car that doesn't leak.
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
Likes: 21
From: Denville NJ
Originally Posted by 65Z01
Those FelPro PermaSeal gaskets are the *****...
A very strong light and a flexi mirror will likely reveal the source of the oil leak.
You might also check behing the intake base for wetness and check the oil temp gauge as the diaphram can develope a leak over time.
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Intermediate
Joined: Aug 2006
Posts: 34
Likes: 0
From: Fremont CA
Oil Leak Question
I found the same oil leak on my 90 Vette. I changed the valve cover gaskets to Felpro rubber gaskets ordered from the dealer. I've taken the oil sending unit, and oil pressure sending unit in addition to the base that hold the sending units together on the block, I cleaned the threads and put Teflon tape on them, did a test run, and still continued to have leaks. Turns out that the oil is leaking from the back and front of the intake manifold. The oil drips off the back of the engine block drives side and lands right on the muffler, which smells pretty bad. I purchased UV Light detection dye kit from Tracer Line Products to really find out the source and sure enough you can easily see the oil leaks. Here is a link to tracer line: http://www.tracerline.com/lampsandkits_tp-1121.html
I have pictures that I would like to share, but I can seem to attach any, sorry.
I have pictures that I would like to share, but I can seem to attach any, sorry.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Originally Posted by CG77VETTE
I did use the GM cork gaskets dry per the Chevy service manager. It looks like I will be making the switch to Fel-Pro rubber. Where is the best place to get them? Thanks for your help.
http://store.summitracing.com/partde...5&autoview=sku
Last edited by Frizlefrak; Nov 29, 2006 at 02:44 PM.
Thread Starter
Drifting
Joined: Jan 2001
Posts: 1,970
Likes: 21
From: Denville NJ
Originally Posted by Frizlefrak
Cork gaskets suck. Install the rubber ones and never look back.
http://store.summitracing.com/partde...5&autoview=sku
http://store.summitracing.com/partde...5&autoview=sku
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Originally Posted by CG77VETTE
Frizle, do the FelPros go on dry like the cork ones or do I need a sealant? Thanks for your help and advice
I went through 3 sets of cork gaskets on my 84 the first 5 years I owned the car, and they all sealed fine for the first year or so....then I would get a whiff of that dreaded burning oil smell and see the puddle in the garage. About 5 years ago, I got fed up with removing the A/C compressor to change the gaskets and I went with the Fel-Pro rubber gasket set and it's still dry as a bone.
A couple of years ago, I decided to change my timing chain. Had to drop the oil pan to do it, and I noticed that it had also been leaking. Went with the one-piece Fel-Pro rubber pan gasket on that too. Couldn't have been easier to install, and hasn't leaked a drop since.
These gaskets are WELL worth the extra money.
Now if I could just get that damned 700R4 to stop seeping....
Good luck...
Burning Brakes
Joined: May 2006
Posts: 857
Likes: 1
From: Morrisonville Illinios
I use some 3M weatherstrip cement some times and a couple of clothes pins to glue it in place so it will not slip when you wiggle it down on. check the sensors and fittlings on the back of the block by the distribitor drivers side. They can be replaced or tightened just a little pia.
Good Luck wro87
check the sensors and fittlings on the back of the block by the distribitor drivers side. They can be replaced or tightened just a little pia.Good Luck
wro87
Le Mans Master
Joined: Feb 2005
Posts: 6,485
Likes: 566
From: Clearwater Florida
Oil leaks
Originally Posted by Muffin
Oil temp sender is directly above your oil filter/cooler. You have two oil senders behind the intake and left of the distributor. Either can leak.
There are two oil sending units at the back of the engine down below the distributor just on the drivers side of center , over time they are prone to developing drooling leaks...they are fun to service , but aren't impossible....there just isn't a lot of space down there for hands and tools...I pulled the distributor on my 87 for more room to work
Race Director
Joined: Jun 2005
Posts: 17,640
Likes: 1
From: Lenoir City TN
St. Jude Donor '08-'09-'10-'11
When you need a gasket always ask for the Fel Pro Perma-dry. These things just do not leak when installed correctly with clean mating surfaces. They are the bomb.