The most common but most unrecognized oil leak

[billschroeder5842]

*UPDATE*

I "think" I may have got it, but the true test will be tomorrow when I drive it..

I did a "hybrid" of some of the past efforts. I took a series of extensions about 22" long and put a U joint at the bottom with 8mm socket. I stood on the inside of the tires between the tires and the inner fenders- damn near vertical from the problem area.

I snaked my right hand down to the (it helps if you coat your arm with car soap) down to the fittings and "found" the bolt heads strictly by feel. I then snaked the extension down with my left hand in the area in between the oil filter and the valve cover, dropping it until it fell into my right hand. I "cupped" the u-joint fitting and fiddled around until it mated with the bolt head. I held the extension/u joint pretty firm to bolt to help with seating and void stripping.

I was able to turn the top bolt about 1/3 of a turn and the bottom about 1/2 turn. It was pretty hard to turn the nut but that could have been part of the angle of the u joint and extension.

I'm not sure if I did any good or not, but I'll take it out in the next couple of days. I spent about 30 minutes on it not counting me messing with a rag to soak up any oil residue.

Fingers crossed!

[Dynomite]

Originally Posted by billschroeder5842

I did a "hybrid" of some of the past efforts. I took a series of extensions about 22" long and put a U joint at the bottom with 8mm socket. I stood on the inside of the tires between the tires and the inner fenders- damn near vertical from the problem area.

I was able to turn the top bolt about 1/3 of a turn and the bottom about 1/2 turn. It was pretty hard to turn the nut but that could have been part of the angle of the u joint and extension.

If you can see them, you can get a wrench on them.....
just takes the right wrench/wrenches (I REPLACED the two 8mm head bolts with 10mm head bolts)

And you have to get the Z off the ground so you have elbow room


Post 249 - Oil Pressure Regulating Valve Cover Plate

See Also...……. Potential Oil Leaks and the OPRV Cover Plate

[billschroeder5842]

*progress report*

I drove the car about 35 miles today (I do love this car) on my round trip commute to work.

I checked for oil in the cradle to verify my "fix" and found that the area was mostly dry- WAY less oil than before about a 90% reduction. I'm not sure if the remaining oil was left overs that gravity finally pulled down, my poor cleaning job or fresh oil but from a much smaller leak.

I'll do another (but better) clean job and have an opportunity to drive the car about 75 miles tomorrow. That will be a more definitive test.

[TX '90 ZR1]

Bill, have you checked the front oil pan bolts? You need to remove the frame braces to get to them. All of the ones on my car were loose except for the one that was totally missing!
Good luck and thanks for keeping your progress updated.

[wutanec]

Sorry to revive this post, this is probably old news to a lot of people.

I am trying to do this by method #2 originally posted by Dynomite.

So by dropping the "strut", it means the diagonal chassis brace that motor mount is bolted correct? Can I really remove this brace without putting a support on the engine? I am going to do this on a 4-post lift and do not want the motor to drop on my head!

[dcarroll95]

Yes you can unbolt that cross brace and engine won’t drop. You can even pull both when you need access to various things.

[Ccmano]

Originally Posted by dcarroll95

Yes you can unbolt that cross brace and engine won’t drop. You can even pull both when you need access to various things.

Correct, you’ll find that the engine mounts sit above the “K” member on their own platform. This is also a good time to check the engine mount for damage. Due to age (~30yrs) and heat cycles these oil filled rubber mounts tend to crack and break. If they have never been changed chances are good they are broken. Looks like this when they go.
H

[wutanec]

Thanks guys, I leased a lift next Monday so I can do a thorough oil leak proofing. Fingers crossed!

[MuRCieLaGo]

This job is a major pain. I discovered oil pretty much all over the place on the ground this morning (especially from passenger side). I tried to access the 2 bolts from above, underneath, from the side... A big hour later, no luck. I had to remove my headers to tighten them with my (left!!) hand. I've got no clue how you do this without removing your exhaust manifold.

Now the car is out of order until I get a new exhaust manifold gasket.

[1991 Corvette ZR-1]

I run the OBX headers but I can get to the bolt closest to me on that cover. On the one furthest away, I happen to have my rack out for service anyway so I was able to reach in through the front to tighten it.