Oil pan leak - Can it be pached in place?

[Deepdraft]

The oil pan on a GM 4-71 leaks from a rusted out area on the pan. - Replacing would require lifting the engine, (major task). I've seen suggestions to use Devcon, or fiberglass a shell in place. Any Opinions?

Thanks.

[capngeo]

I've lifted over 100 engines to fix bad pans... If you come up with a permanent in-boat fix, let me know PLEASE! The best temporary fix I know of is RVT Silicone... saw one hold out for 6 months on a tug boat genny!

[svHyLyte]

Empty the pan as completely as possible; clean with Mineral Spirits followed by Acetone and a wire brush; mix up a batch of MarineTex and lay that on over a fiberglass mesh spanning the holed areas. If marinetex can repair a mixing elbow (it did mine for quite awhile), it will an oil pan as well.

FWIW...

[capngeo]

Epoxy doesn't like oil at all! Marine Tex is great stuff, but not for oil pans!

[svHyLyte]

Originally Posted by capngeo

Epoxy doesn't like oil at all! Marine Tex is great stuff, but not for oil pans!

Why? If the substrate is clean and rough it will bond tenaciously and, once cured, is inert. It will handle temperatures up to 275ºF with periodic spikes to as much as 325º. IF it can be used on diesel fuel tanks and mixing elbows, why not a pan that generally operates at 180º or less and under very little pressure?

[Therapy]

J B Weld.

[capngeo]

Originally Posted by svHyLyte

Why? If the substrate is clean and rough it will bond tenaciously and, once cured, is inert. It will handle temperatures up to 275ºF with periodic spikes to as much as 325º. IF it can be used on diesel fuel tanks and mixing elbows, why not a pan that generally operates at 180º or less and under very little pressure?

There is the problem! Granted IF you could get the pan clean enough epoxy compounds would work in theory... I've never got them clean enough!

[Cotemar]

Where their is one pin hole leak there are 1000's coming soon.
Patches are as stated "PATCHES". Take the time and do it right the first time.

[knotnow]

I agree with all that advice not trying to patch the pan while installed. Whatever magic mechanic in a can compound that you can come up with the simple fact is there is residual contaminants inside the pan. Do yourself a favor and at least lift it and block it, remove the pan, clean it and then decide if patching is an option. I do this for a living, believe me or you’re pi$$en in the wind.

[capngeo]

Often I have seen leaks only in one small area.... the one sitting in the bilge water!

Honestly, were it my boat, I'd lift the engine and repair it right.... Captain Murphy's law states that the patch will fall off and you'll lose oil pressure at the most inopportune time!

[Lancerbye]

Having also done a fair bit of engine repairs I will agree with the three previous posters. Replace the pan with a new one.It is a different situation than a leaking gas tank. If you lose your oil when you need that engine, you will wish you had spent the time and money to have done it right to begin with.

[senormechanico]

After finding a couple of pinholes in my Volvo MD 2020 pan, I got agressive with a wire brush on the inside of it.
Then I soldered about 20 pinholes with rosin core solder and a propane torch, and painted it.
That was nearly ten years ago. It's still holding oil.

[knotnow]

Originally Posted by senormechanico

After finding a couple of pinholes in my Volvo MD 2020 pan, I got agressive with a wire brush on the inside of it.
Then I soldered about 20 pinholes with rosin core solder and a propane torch, and painted it.
That was nearly ten years ago. It's still holding oil.

I would say you’ve been lucky. If it’s obvious that the damage is from corrosion we replace it.

Think of it this way, you’re outside, the sea’s rising from 10 and the winds are past gale, I’m not concentrating on my oil pressure gauge to tell me that I’ve just dropped 8qts. of oil in the bilge.

[Chief Engineer]

Replace Pan.....you will sleep better

[svHyLyte]

Originally Posted by Chief Engineer

Replace Pan.....you will sleep better

Chief et al are undoubtedly correct, but if ya gotta get home sometimes ya gotta make do. I did however make the suggested repair on the pan of a 2GM20F and it did work until we got to a place where we could lift the engine enough to replace the pan. (Now that was a real job!)

FWIW...