oil pan leak

[Richard M.]

Re: oil pan leak

Bruce,

Yes that repro timing chain cover is most likely the source of the leak. The lower flange is spot welded. The oil leaks between the welds in the spaces. Poor quality fabrication

Once removed, you could repair it. Use brake-clean on the flange to remove all traces of oil. Using a torch and silver-bronze rod, braze in the seams. You could also use silver solder. I've done that before with good results.

Unfortunately, another case of making repro parts work.

Keith, This may be your problem too even though yours may be original GM. The welds can separate over time. The worst part of all this is that darn front engine mount needs to come off to pull the timing cover on a C1.

Rich

[Bruce W.]

Re: oil pan leak

Rich,
Thanks for the tip. Here we go again. Pan has to come off. I will let you know if that fixes the problem'
Bruce

[Richard M.]

Re: oil pan leak

I may have some photos buried in one of my restoration folders showing the cover differences. I'll look for them.

[Keith R.]

Re: oil pan leak

Thanks for chiming in Rich. My leak appears to be originating at the top of the gasket between the block and the gasket on the passenger side near the 1/2" bolt then running down the timing cover. When I pulled the pan previously (like six times!), the timing cover galley was dry and there was no evidence of oil in the "U" so I think that its something other than that.

[Bruce W.]

Re: oil pan leak

Rich, that would be appreciated.
Bruce

[Richard M.]

Re: oil pan leak

Here's a file photo from from a '60 restoration that I did. A original cover. You can see the continuous weld on the face of the cover where the internal flange is attached. NO oil will leak at the flange.
P9100005.jpg P9100006.jpg


Here are a few repros, with the spot welds. Some have 5, 6, 9? Whatever the number....It's useless. The oil weeps between the welds. Why/who/what designed these is beyond me.

3 welds
rnb-635-512_xl.jpg

6 welds


This one from CC has 8 spot welds. Hmmm, 7 places to leak from!
302332.main.jpg

(or 9 counting the space above the top welds)
302332-1.main.jpg

Last photo below is a file photo from John Hinckley showing a original. Thanks John! (Get Better!)

[Keith R.]

Re: oil pan leak

Bruce and others - yesterday I started the car and ran it until warm and it was still leaking. I was able to determine however the exact point of the leak. It is originating on the right side of the timing cover at a locating pin where the cover is slightly deformed and the cover gasket is apparently not sealing at that point. (see attached pic). I could clearly see the oil emerging from this point and forming a rivulet which ran down the gasket to the lowest point of the pan where it gathered and dripped off. I am planning on filling that gap with red RTV this morning, let it set for a couple of hours then gently tap the cover back in place.
oil leak location.jpg

[Richard M.]

Re: oil pan leak

Glad you found it Keith. Strange place where it happened.

[Mark E.]

Re: oil pan leak

Good detective work Keith. The timing cover flange does look bent.

[William G.]

Re: oil pan leak

I have a 67 small block and thankfully kept the original oil pan after replacing it with a new GM from a sealed box! After rebuilding the original engine and putting it into the car, with the new oil pan, I also had a seal leak, but it was at the rear of the pan. When I discovered the leak, I thought it was a freeze, or cam plug on the rear of the engine. A video camera inspection showed a completely dry rear casting of the engine.
Talking this over with my machine shop authority, he was the one who turned me onto pan fit issues with new replacement pans. Trust me, I tried everything, from making tracing patterns to clay impressions, only to have the pan keep leaking! My last ditch effort was to use the one piece gasket, knowing I would get dinged on judging points, and my original pan. I had to dolly some speed bump dents out of, but I was able to stop the leak! I still scratch my head thinking about why the new replacement pan would not seal, but after three try's and no success, I will accept some of scratches on the bottom of my original pan and have a dry garage floor!

[Bruce W.]

Re: oil pan leak

Rich,
Thank you for the pictures. It was the timing chain cover leaking exactly where you said from the spot welds. I purchased the correct pan with the 2 1/4 smaller radius in front. I also found a correct original timing chain cover. Leak FIXED!!! thanks Rich.
Let this be a lesson to anyone thinking of buying Chinese crap.t is all junk!!!!!
Bruce

[Gary B.]

Re: oil pan leak

Rich,
Thank you for the pictures. It was the timing chain cover leaking exactly where you said from the spot welds. I purchased the correct pan with the 2 1/4 smaller radius in front. I also found a correct original timing chain cover. Leak FIXED!!! thanks Rich.
Let this be a lesson to anyone thinking of buying Chinese crap.t is all junk!!!!!
Bruce

[Bruce W.]

Re: oil pan leak

Keith, i don't know if you saw my post. Timing chain cover was china crap. sold by CC. Put on an NOS oi; pan and timing chain cover and it is fixed. You know the frustration this can cause!!! had that pan off 5 times!!! How did your come out?
Bruce

[John R.]

Re: oil pan leak

Excellent thread! I've been experiencing similar issues on a '64. Now I have more to check.

[Keith R.]

Re: oil pan leak

Nice work Bruce. It must feel good to have your leak fixed after all you've been through on this. I'll post the results of mine once I crank it over later today....