Oil pan crack - PeachParts Mercedes-Benz Forum

ronald_m · #1 07-20-2002, 02:07 PM

My oil pan got an inch crack on the front engine .Is it possible to weld it without removing the oil pan(its very accesible tho)what kind of welding do i need?Can i use wtv or high temp metal epoxy?Thanks in advance.My car is 93 2.6 M103 engine.

stevebfl · #2 07-20-2002, 02:31 PM

It is pretty hard to weld with the pan on usually. The type of welding necessary would be TIG welding.

TIG, Tungsten - Inert Gas welding is sort of like torch welding. The concept is to be able to apply heat untill the subjects are liquid and then connect the puddle, maybe with some filler (of similar material - welding rod), and let it solidify as once piece.

The point with the Tungsten is to have a point source of high energy current that is not consumed. The arc brings the heat, like a torch. The point of the inert gas is that aluminum burns at the temperature that it melts at. The oxides form barriers to a uniform puddle if only in small amounts. Here is where the problem comes with the pan being installed. The oxidants aren't just the oxygen from the air. If any oil remains in the crack the oil acts as the oxidant and the inert gas can not suppress it. Ask how i know this.

It can be done if the pan is washed thoroughly and drained and then heated first with a torch till all the oil is gone in the area of the crack. Of course I'm not sure how to wash the pan without using something likely to explode when heated with the torch.

The plastic metal will be OK if you find a product that doesn't fall off someday while you are driving down the road. I have used a product called Aradite (sp?) made by Ceiba- Geigy (sp?). A friend introduced it to me. He first used it to fix a porosity that was happening to GM automatic transmission cases. It was a factory service procedure or bulletin in the early 80's.

Also, don't expect the plastic to do any structural portion. It can be used to stop leaks, but I would not consider it safe for a structural patch.

ronald_m · #3 07-20-2002, 02:48 PM

Thanks Steve,
It's only a hairline crack so the oil seeps in a very small amount(1 drop/30min)i guess.So i need to drain the oil and clean the pan then rent a tig welding.

ronald_m · #4 07-20-2002, 04:08 PM

I called Home depot and they only have " mig welder" what the difference between tig and wig and I need to know what kind of metal does the oil pan have.

DanielW · #5 07-20-2002, 04:26 PM

I think you should not try TIG on the car....especially if you are not familiar with that welding skill and have lots of experience. I sounds like you have to have the crack horizontal so that the puddling of molton metals can be have gravity help rather than just run out when liquid.

I successfully usedJ B Weld to repair a crack in a motorcycle (Yamaha FJ1200) crank case. Alum. crack about 1/2 long which seeped a small amount of oil. Just like someone else reported, It won't stand up to structural stress but has completely stopped the oil for several years now. Clean the area outside the crack with laquer thinner and sand paper. Deep scratch a 1/2 inch "border area" and apply JB (about 1/8 or more of depth)before any new seepage of oil contaminates the area. Try it you don't have any thing much to lose. $4.00 or so! That Tig is going to make you buy a whole new oil pan or worse burn up your car......my 2 cents !!?

good luck man,

Wish I had someone to help me replace the water pump on my 300E.. That sucker is BURIED under a lot of other components!!

Daniel

rmmagow · #6 07-20-2002, 05:09 PM

For what it's worth I would give JB Weld a shot. You'll have to superclean the crack area and it would probably be a good idea to grind out the crack a little with a dremel tool type thing. Follow the instructions on the package. I've used this crap to patch blocks with good success. Worth a shot at the price.

ronald_m · #7 07-20-2002, 05:14 PM

Do you think Jb weld can stand the heat of the oil.this is the thing you can find on pep boys right?

rmmagow · #8 07-20-2002, 05:30 PM

I believe JB Weld can stand the heat of a Titan Missle. This stuff has been around for a long time and is well proven for what it's intended to do. I'm 50+ yrs old, my dad used to use it on his cars. I remember him using it to fix a stripped thread in a block, filled the hole, tapped it and put everything back together. Car ran for 10 yrs afteer that. It's pretty high quality stuff and available at any hardware store.

#9 07-20-2002, 05:41 PM

Araldite is the product that Steve is referring to and it is a two part product that from what I have heard about JBWeld, sounds very similar.

Matt.

stevebfl · #10 07-20-2002, 06:05 PM

JB Weld is tough as nails but doesn't stick well. With proper preparation it may stay.

Maybe you missed my point. TIG welding would be the repair method of choice if you could take the pan off and take it to someone who TIG welds. A good TIG welder costs more than three pans.

MIG welding is not like TIG welding and although when using inert gas it can weld Aluminum alloy it is a very poor way to do so as the electrode is also aluminum. It will deposit gobs of rod before hot enough to penetrate aluminum. Takes twice the power to weld aluminum as opposed to steel, even though it melts sooner and has a lower specific heat. Anyone know why?

ronald_m · #11 07-20-2002, 06:46 PM

steve,
I assume that the oil pan is an aluminum alloy,Am I right?

#12 07-21-2002, 02:57 AM

Ronald M :::

Why not just buy a new oil pan?

This would give you an opportunity to clean or replace suction unit as well.

I don't think that experimenting with an area as critical as engine oil is a good idea.

Of course just my personal opinion.

I would call Caliber Motors for the best price on genuine replacement parts. They have been very good to me.

Good luck.

s/b

David C Klasse · #13 07-21-2002, 06:23 AM

I once drove out of a gas station too fast and cracked my oil pan pretty bad. My independent mechanic used JB Weld and it sealed right up. It's been almost 2 years, and 50k miles now.... still holding up.

#14 07-21-2002, 10:07 AM

JB Weld would be my first choice. I have used this stuff on a number of applications over the past 30 years, i.e. carbs, magnesium valve covers, aluminum items, and piping. Granted, a weld or pan replacement will definitely fix the problem, but a minor seep is an easy fix for JB weld. Just clean the area, make the mix (nice gray putty look), apply evenly. I would allow the fix to mend for at least 24 hrs.

Hope this is helpful.

#15 07-21-2002, 10:23 AM

Yes, JB Weld. I fixed a leaky gas tank with it. A friend of mine fixed a cracked water pump, still running, 2 years later. Give it a try.

sbr
'79 450SL
77,000 miles