Looking for a permanent fix for hole in oil pan m50b20 without replacing it

[shiremux]

Hey everyone, i recently discovered that my oil pan has a major leak, it has been fixed with silicone by previous owner but the silicone came off and im losing about 300ml of oil monthly, i dont want to buy a new oil pan for couple of reasons, first, im gonna swap the engine in couple of months hopefully, and second of all, cost of new oil pan and replacement will probably cost as much as used m50b20 engine, i just see no profit in fixing this considerign that the engine has a lot of other problems that will cost as much as new m50b25.
So, is there a way to fix that will last half a year atleast? Something that will hold a bit better than sylicone?

[TheStigg]

https://jalopnik.com/5935258/the-sup...ncy-repair-fix

[shiremux]

Holy crap, briliant guy. Thats a good idea but my leak is on the side with "fins", that can be very hard to make a bowl in this place but ill keep thinking, anyway, JB weld, never heard of, thaats gonna help a lot!
Thanks mate!

[TheStigg]

If you can keep it clean and dry long enough to apply a patch, you could form a "bandaid" with a portion cut out of a beer can and glue it around the leak region with a good quality sealant. Permatex "Right Stuff" is a great sealant and is impervious to oil after 5 minutes. Clean the leak area with acetone and a wire brush and blast it with compressed air and repeat. I'm assuming the leak doesn't pool oil from the inside after it's drained. If so, then jack the car up on a tilt to make sure more oil doesn't collect while you're doing the repair.

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[moroza]

I doubt there's anything you can do without at least draining the oil. One idea that comes to mind is drilling and tapping the hole, and fitting a bolt with a gasket into it.

[fo3]

Holy crap, briliant guy. Thats a good idea but my leak is on the side with "fins", that can be very hard to make a bowl in this place but ill keep thinking, anyway, JB weld, never heard of, thaats gonna help a lot!
Thanks mate!

JB weld is just a USA brand of metal epoxy. Devcon 'plastic steel' metal putty is another name brand that's more familiar in Australia as we don't get JB weld either.
It's going to be difficult to bond anything in an oil stained sump so I agree the pro move would be to drill, tap and use a bolt with a washer - just like your sump plug. Cut, die grind or dremel out any cooling fins in the way.

[shiremux]

A bolt with washer sounds better, how should i attach it? Just by screwing it in or with silicone or perhaps welding it?

[moroza]

A bolt with washer sounds better, how should i attach it? Just by screwing it in or with silicone or perhaps welding it?

One idea that comes to mind is drilling and tapping the hole, and fitting a bolt with a gasket into it.

[Billyj]

Weld it would be easiest. If it's a crack, drill the ends of the crack to stop the spread then weld. If it's a small hole maybe try drilling it out to round and then some sort of rubber freeze plug

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I think it's going to be hard to tap such thing metal... Or are we talking the thicker part of the pan?

[shiremux]

Oh, sorry, english is not my main language, had to look up what "tapping" means, now it makes sense

[moroza]

It's ok. Just so we're clear, I mean this:


It may or may not work if the metal is too thin. I would use a large fine thread (perhaps M12x1.0) and a rubber O-ring. And per the thread title, this would not be a "permanent" fix. The correct fix is to remove the oilpan and either replace it, or have it welded by someone who knows how to weld aluminum. I'm not a professional welder but my guess is that you will not get good results unless all the oil is cleaned away from the area, inside and outside, which is impossible without removing the pan.

[shiremux]

It's ok. Just so we're clear, I mean this:


It may or may not work if the metal is too thin. I would use a large fine thread (perhaps M12x1.0) and a rubber O-ring. And per the thread title, this would not be a "permanent" fix. The correct fix is to remove the oilpan and either replace it, or have it welded by someone who knows how to weld aluminum. I'm not a professional welder but my guess is that you will not get good results unless all the oil is cleaned away from the area, inside and outside, which is impossible without removing the pan.

Yes, im aware of that, thats why i think maybe i will drain all the oil, as much as i can and clean it up, and then perhaps just apply another patch of silicone and/or some sort of JB weld, it has to hold for a couple of months max, i think i shouldnt remove the existing silicone patch, i know it leaks but atleast it holds some of the oil and if i remove it, im stuck with finding a new solution that may not work better than existing.
If just replacing the pan wouldnt be so hard..

[katit2]

I think this discussion is pointless because we didn't see "hole". I'm just guessing here (seeing OP from Poland) that there might be translation issue (english is not my primary language either so I know)

So, what kind of "hole" is that? I can't imagine hole in oil pan which can be drilled and tapped. Hole comes from impact. If it was hit and there is hole there would be more than 300ml coming out.

If there is "crack" - I can assure you it can't be fixed without at least removing pan and making it perfectly clean.

So. I think it's plain old gasket leak. Or, even more I think it might be oil filter mount leak that comes down to oil pan. Again, without pictures - just speculations here.

Step #1 - clean area really good. Detect leak and post pics..

[ross1]

Just a thought
If going the epoxy route a bit of negative pressure in a drained crankcase ought to prevent oil from fouling the repair and might even draw a small amount of the epoxy into the crack. Be careful not to apply too much vacuum, like full suck from a shop vac, or you could ruin gaskets and seals.

[Onizukachan]

If crack, drill ends to stop continued cracking, then use job weld or similar to bandied it.
Problem is the aluminum is massively fouled. You can weld it but the weld itself will seep oil and you’d still have to band aid it.

[shiremux]

i think ill just give it to the nearest mechanic and give them few of the ideas given there, hopefully they can patch it up, i dont have the neccesary skills or tools to do it ;<

[Billyj]

Any good mechanic will tell you to get a used replacement

[moroza]

What Billy said: a mechanic is going to tell you to replace it. It's not hard to do with the engine in. You may have to drop the subframe, which is easier than it sounds.

[shiremux]

I just got under the car to make sure where the leak it, it is right under the bolt to drain oil during oil change, damn, the whole bolt head is patched with silicone, i think this leaves me with no choice but changing the whole pan...
One more thing so i dont create new topic, my bimmer is 1995 sedan with m50b20, realoem says that i should get oil pan with numbers 11131740340 or 11131740346, i cant find them tho, what i found is a pan with number 1740339225 that says it will also fit my engine, can anyone confirm it? i cant find that part on the realoem site with this number.

[shiremux]

What Billy said: a mechanic is going to tell you to replace it. It's not hard to do with the engine in. You may have to drop the subframe, which is easier than it sounds.

Dropping the subframe? Have u done it? all the info i found on the internets says i have to lift the engine up and its still like 9/10 difficulty, have u got any tutorial for this job?

[moroza]

Yes, I've dropped a subframe like that a few times and twice on an E34, but I do this for a living. I would rate the job 7/10, not because it's very difficult, but because there are several medium-difficulty steps, and a safety concern (working underneath a suspended engine). I just did it using a jack, no engine crane required. However, I wasn't taking off my oilpan... If you can rent an engine crane with a safety lock (or improvise one*), it'll be easier - just suspend it from the crane, and make sure there is something more than a hydraulic seal keeping the ~150kg engine from reaching down to give you a kiss. If not, place jackstands under the motormount brackets in a way that won't slip. Use your judgment regarding your safety, mechanical skill, and experience.

*I did this once: two empty oil barrels upside down next to each side of the car, which is on jackstands at the main frame. Stack of wheels and pieces of wood on top of each barrel. Strong steel pipe laying across both barrel stacks, over the engine. Jack up the engine at the oilpan, maybe 4cm, with a piece of wood to protect it, and attach it securely to a chain around the pipe.

Basic outline is:
- suspend engine by its hooks or motormount brackets (not on the oilpan or too close to it, but you can rest it on the oilpan until the subframe is removed, then transfer to the motormount brackets)
- disconnect steering column U-joint at the steerbox. No real tricks, it's just very tight. Mark it first to reassemble in the same position later.
- if you're just replacing the oilpan, you might be able to leave all the control arms and steering (except the column) attached, and lower the subframe just far enough to get the pan out. Otherwise, disconnect the lower control arms at the bushings, the steering at the tierods, and the power steering hoses at the steerbox. The bigger (return) line can instead be disconnected at its hoseclamp to the cooler line, leaving it attached to the box and saving you from having to replace two 16mm aluminum gasket rings. The smaller (pressure) line from the pump will need its 14mm rings replaced anyway.
- remove six 17mm bolts holding up the subframe.
- the subframe is a tight fit on its dowels (Precision!) and will probably not come down on its own. Depending on rust, it'll either come down with your arms or it might need help from a large hammer and oil. Mine was tight enough that the weight of the engine wouldn't move it. With steerbox and center steering linkage, it weighs something on the order of 20kg, maybe 15kg of which is the steerbox.
- the oilpan is a bunch of normal bolts to the block, and a couple of E-Torx weird bolts to the transmission.
- reassemble in reverse. Use new aluminum crush washers for any banjo bolt you disconnected. Bleed the steering hydraulics, and make sure to tighten any loosened control arm bushings in their loaded position.

But if you're actually replacing it in a month or two, maybe not worth the effort?

[shiremux]

I cant be sure if its month, two or half a year and the last oil change was 10k km ago, since then i just added 1l of oil due to the leak and thats it, i dont want to know whats inside the oil pan
If i could just be sure that the bleeding screw will hold on i'd leave it, maybe ill give it a shot and unscrew the bolt and see if i can manage to change the oil and leave it like that without bigger leaks.
Anyway, there are 2 ways of changing the oil pan, either by lifting the engine or dropping the subframe or it has to be both?
From all of the DIY tutorials i've found your's seems hardest to be honest

[katit2]

I made my own engine brace from metal profile long time ago. Then you just attach engine from a top to hold and drop subframe..

[shiremux]

I think i could put the car on the jackstand and unmount 1 motormount and lift the engine with floor jack using some huge piece of wood or metal pipe

[moroza]

You might have enough room if you just lift the engine off the subframe, I don't know. The above description is a worst-case scenario.