Can a damaged/leaky oil pan be welded?

[Learning]

First, an oil pan has 2 sections (upper and lower), doesn't it?

Months ago, the oil pan of my 318i was damaged while being towed.
I thought the mechanic who I asked to fix this damage would have replaced the whole oil pan with a new one (because the towing company's insurance paid for the repair), however, I just found out he didn't put a new one on (what a sneaky mechanic !). He only welded the upper side of the oil pan to fix the damage and seems like he only replaced the bottom part of the oil pan with a new one. Now, oil has been leaking from a hole where the welding is on the upper oil pan. I found this out after I took my car to Brake Masters to be inspected for oil leak. The manager at BM told me, "Pressure built up and thus the leak. Oil pan is made of aluminum and you can't weld aluminum. The mechanic who repaired your car didn't replace with a new oil pan because it was the cheapest way to do it" Is it true what he said that aluminum couldn't be welded?

I found after searching on line that oil pan which is made of aluminum could be welded. However, my worry is will a leak easy to occur again although the welding is done well?
I wonder how expensive is a brand new upper part oil pan?

[travish325]

You can definatly weld aluminum (even the shitty cast aluminum pans are made of) And if its welded properly by an experienced welder it should not leak. Make sure if you get it welded its taken off the car not left on, and cleaned well. Dirty metal does some shifty stuff to welds

[Learning]

The manager of Brake Masters told me that aluminum couldn't be welded because when the car gets hot the aluminum oil pan would expand (it needs to breathe) and so there would be leaks again as the weld couldn't hold well when the aluminum expands.

What are your take on this guys?

[ak-]

Mine is welded in 3 places after 3 incidents.

An experienced welder can do it no problem.
And yeah that mechanic was being cheap, I guess, if it had to come out of his pocket.

[travish325]

The manager of Brake Masters told me that aluminum couldn't be welded because when the car gets hot the aluminum oil pan would expand (it needs to breathe) and so there would be leaks again as the weld couldn't hold well when the aluminum expands.

What are your take on this guys?

Bull shit

[Learning]

Yes, sneaky mechanic. I went to him because he got great reviews. Eventually, something stinks would smell.

From reading on line, I learned that a crack in an oil pan (upper part oil pan in my case) could be fixed easily using J-B Weld epoxy. Has anyone tried this product? How successful are you?

ak-, did the welder have to take your oil pan off before starting fixing the cracks/holes in your oil pan? I also learned that high temperature from welding could warp an oil pan.

[travish325]

Sounds like you are learning a lot.

[ak-]

Yes, sneaky mechanic. I went to him because he got great reviews. Eventually, something stinks would smell.

From reading on line, I learned that a crack in an oil pan (upper part oil pan in my case) could be fixed easily using J-B Weld epoxy. Has anyone tried this product? How successful are you?

ak-, did the welder have to take your oil pan off before starting fixing the cracks/holes in your oil pan? I also learned that high temperature from welding could warp an oil pan.

Yes you need to take off the pan and clean it from the inside/outside.
Can't weld dirty metal. Well, you could, but lol.

[ak-]

el o el

[bmwman91]

OK, you most certainly can weld aluminum. Ever seen an aluminum frame bicycle?

Dirty metal does not weld well, especially aluminum. Not only do you have to clean it off, but you need to scrape the oxidation off and weld it within a couple minutes of doing so before more aluminum oxidizes (aluminum oxide melts at a MUCH higher temperature than aluminum and it can basically form a blister of molten Al while trying to weld which is a hge pain in the ass).

The oil pan is relatively thick metal, and it would most likely need to be welded from both sides to prevent it from fracturing again after all the thermal cycling that it goes through on the engine. The guy at the brake shop was probably describing something along those lines.

If you are too cheap or too lazy to pay for a proper weld with the pan removed, JB weld works just fine. I busted a hole in my oil pan many years ago and put almost 80k miles on the thing with no problems. You really should not use it to fill large gaps, but assuming that it is just a crack and the original metal is all still there, it is fine to slather it over the outside to keep oil from going through the crack. Be SURE to clean the working surfaces well though, with MEK or at least Isoptopyl alcohol. JB Weld is like any other adhesive in that it doesn't work well with dirty surfaces. Give it 24 hours to cure (48 if it is cold where you are) and you are good to go without the hassle of removing the oil pan.

[Learning]

The mechanic will re-weld my oil pan for free (hopefully), however, the hassle seems would be to take the oil pan off (but in my case here the crack is in the upper side of the oil pan) and so maybe the mechanic won't have to take it off the car and instead he just needs to drain all the oil and clean thoroughly the crack in the upper side of the oil pan before welding it.

What do you think guys?

[AndrewBird]

The inside of the pan needs to be clean as well. If welded properly, the weld will reach through the pan into the inside and contaminates can get in there. Not to mention, any residual oil in the pan will burn from the welding heating the pan up, resulting in a bunch of burnt oil inside your engine.

Proper way of doing this is pull the pan, clean thoroughly, grind a V groove over the crack, then fill the void with weld.

Either that, or just get a used pan. Unless you can get the welding done for free and know it will be done correctly, getting a used pan will be cheaper.

[Dj Buttchug]

i have a upper pan for 60 bucks shipped... Seems like you are going through a lot of hassle. Might be easier and less ghetto to just swap pans?? As stated above there is nothing wrong with welding a pan, as long as its done correctly

[Learning]

Are you sure it's only $60, Dj? It looks like the upper pan is sizably larger than the lower pan. I checked on line and it was about $300.

By the way, today I took my car back to the mechanic who welded the pan. He checked again to find the leak and he said it was the timing belt cover gasket. The car was on the rack and another mechanic revved the engine and I could see the leak coming out from the timing belt cover. And so I think the BM manager was wrong because what he showed me was perhaps oil dripping down from above to the welded area, but I think I remember seeing oil coming out from the cracked welded area. Could there be 2 leaks?
However, when I opened the hood I could see oil splattered to some parts of the engine. Could the timing belt cover leak ring truer?

Is it a big job to replace a timing belt cover gasket? The mechanic said it was going to take about 4 hours to do the job. Is this right?
Should I have him also replace other gaskets/seals when doing this job because he's going to lift off many of the engine parts anyhow?

[bmwman91]

Is it leaking from the area where the two black rubber gaskets meet up end-to-end? That's easy to deal with. Let the car cool down and clean the area with alcohol. Get some Permatex Ultra Gray RTV adhesive and work it on with your finger, pushing some into the little gap between the rubber gaskets. Once the area is covered, let it sit for a day and you'll be good. I did that a few thousand miles ago and have had no issues since.