2000 Mercedes E300 Diesel oil pan crack

Barky, here’s the plumber’s epoxy. Oatey® Fix-It™ Stick Epoxy Putty | Oatey

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I use to fix my exhaust system leaks with muffler putty in the old days but I wonder if it would work in this application.

I looked at the website, but I didn’t see anything about it being oil resistant.

I will try the soap, as soon as I can get the flex seal off.

You need to look at @Mustangman 's suggestion. Don’t put any other contaminants on it, like soap.

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I’d suggest soap won’t work. Oil pans get hot… 200 degrees hot. That melts soap and the glues used on tape. Gas tanks don’t get hot.

You need a material that will bond to the crack, resists oil and can handle heat. RTV gasket sealer will handle that but it is not structural. Epoxy is structural and there are oil and heat variants of epoxy. I posted a link to a commonly available one.

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It doesn’t mean that you should skip oil changes, though. There’s still old oil in the engine that is used up and needs to come out, plus the filter still needs to be changed

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Thank you all for your input. I have enjoyed the conversation. I will use the high heat JB-weld after the flex-seal tape starts leaking more. And of course, I will report back with any updates. The JB-weld link. https://www.jbweld.com/products

The operative word is “more”.
Based on my experience with FlexSeal tape, I think that the product borders on a scam. Last year, I used it on a garden hose and it couldn’t even stop water from seeping through the hose, so I have a hard time imagining that it could work for the long term with motor oil, or that it would even work–at all–with motor oil.

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Brain fart I guess, not sure about the temp either.

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Find a shop that has a tech that knows how to TIG weld.

Tester

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Maybe it is different for tig on aluminum, always heard the oil soaks into the pores of steel and makes welding difficult. Just out of curiosity I picked up some rods for use with a blow torch at a state fair a number of years ago. Thnkingof using them on a pontoon boat of a bud. Anyone have any experience with them? I have not experimented yet.

I used those on my seat frame. It is just like solder, not welding. So there is no more strength than solder, and like solder everything has to be very clean for it to take-no flux. Welding is a whole 'nother matter and stronger, plus it doesn’t melt again if you put heat on it like solder would.

I had a small engine welded that had a thrown rod through the block. The guy was a good welder and never had any problem with oil saturating the block. Charged $10. Welding overhead on the pan though would be a little more difficult but I’d sure go for that if the logistics allowed. I’ve got a wire feed but never hooked the gas up for aluminum or gas shielded. I know I should but you have to rent the tanks with a 5 year lease.

So yeah, you could solder on the pontoon tanks but nothing structural with that stuff.

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Several years ago my pontoon developed an 18" crack near a bow ‘wing’ that was repaired by the marina mechanic with zero experience. He had turned down several potential jobs due to lack of equipment and training. He apologized for the appearance caused by the overkill in the repair but I was pleased. He drilled at the ends of the crack, skived out the length of the damage and ran a rotary sander over the length also. The repair was intact years later when I sold the boat. But I would consider the area structural @bing. Crossing high wakes even at moderate speeds was the likely cause of the crack it appeared.

This would be my solution if I had the time and personnel. looks like these guys got the oil drained very well. I would imagine some oil still leaking with that size crack, even after drain. Maybe they ran a cloth inside the soak up all the residual?

What is the reason for drilling a hole at the two ends of the crack?

To relieve stress on the crack plus have a clean edge .

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Interesting… I guess you should drill a hole even if the leak is a pin hole smaller than the drill diameter?.. And that is what the dentist is doing with cavities… Cool!

I think the dentist is just making sure all of the decay is cleaned out. If welding I don’t believe drilling holes is necessary since welding is actually fusing the metal with a filler material. There would be no point in drilling a hole only to have it obliterated again with the melting of the metal. Soldering though as @Rod-Knox mentioned (which is what this type of “aluminum welding” really is) is just over-laying the melted rod on the crack, so there would still be stress in the metal as in a windshield crack. Of course if you heat the aluminum up too much with the torch and the rod, you’ll melt it-“another fine mess you’ve got me into”.

At any rate back to the oil pan, there is no way to use the aluminum rod upside down on the pan without removing it. (At least unless the person is very skilled. A guy once soldered up a hole in my transmission line but he was very good.) The solder will just drip out. You could weld it though but you have to get it to a shop that can weld aluminum, drain the oil, clean the crack, etc.

I wouldn’t. Those holes are drilled for stress relief, like what happened with the boat, above, or what happens when, say, the aluminum skin of an airplane has a stress crack. Your crack was from hitting something, like a rock, and won’t likely continue to spread on something so unstressed as an oil pan.

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Try JB weld. I once used that on a Ford F250 460 engine that had a cracked frost plug in the side of the engine and it never had a problem after thousands of miles like that including going on a 1000 mile trip non stop. Only cost a few bucks and you will have some of the stuff left over.