Now I'm Angry - Leaking Oil Pan Gasket AGAIN

[CamE32]

Some of you may recall I paid my mechanic for an oil pan gasket replacement less than a year ago (wasn't feeling up to lifting the engine, and they discovered via a smoke test that a large chunk of the original gasket was missing) - but they reinstalled every single bolt only hand-tight and it developed a leak after some months of daily driving. By the time I discovered the bolts barely hanging on, it was too late: torquing them to spec (10NM) made no difference.

I wasn't happy at all, but gave them a chance to make it right - so they did the job again under warranty and this time noted on the receipt: "Removed oil pan and replaced with liquid sealant due to problems with it"

Now it's ~2 weeks later and the gasket is LEAKING AGAIN!! I just discovered it today after 2 days of daily driving to/from work (car had been sitting for a week before that)... noticed a small oil puddle at work and then crawled under the car to find oil seeping from the gasket AGAIN. Now I'm really angry.


I sent the following message at 6:30PM because I'm too riled up for a phone call/voicemail at the moment:


"Just discovered the oil pan is still leaking.
To recap: the first time, when I paid for this job, every single bolt was reinstalled only hand tight. And it still took months of daily driving for a leak to develop - but by the time the leak started and I discovered the loose bolts barely hanging on, torqueing them to spec (10NM) didn't help.

So WHY IS IT STILL LEAKING? I have to assume it's because an excessive amount of sealant was used the 2nd time, which has already begun to fail from the heat cycles (I checked the bolts and they are tight this time).

So what now? Call me please."



If I had the $$$$ I'd take Croughton's advice and just bring it up to the Boston area where I know of some very-reputable classic BMW shops. Still debating that option, but another ~$800 repair would really hurt the bank.

Even if my mechanic does the job CORRECTLY, on the 3rd try, I will never go back to Roundel Motor Werks (Sandwich, MA).

/end rant

[robertjlewis1]

Is it the lower or upper sump gasket that the leak was from. On mine the upper sump gasket had gone brittle through the heat output over the years and caused a constant oil leak. Engine out, on a cradle and replacement of both gaskets solved the problem. (And most other gaskets whilst at this point)
Sealant alone is pointless as it doesn't give the correct seal through gasket compression as a normal gasket would.
Hope you get it sorted!!

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[shogun]

@:robertjlewis1: CamE32 is talking about a 735 with M30 engine, not a M70 with upper and lower oil pan, M30 oil pan looks like this http://bmwfans.info/parts-catalog/E3...browse/engine/

[robertjlewis1]

@:robertjlewis1: CamE32 is talking about a 735 with M30 engine, not a M70 with upper and lower oil pan, M30 oil pan looks like this http://bmwfans.info/parts-catalog/E3...browse/engine/

Oops sorry, my mistake.

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[whiteghost1]

I feel for you, most of us have probably had a similar mechanic experience as you, I know I have.
You did pay for the work, and most reputable shops will honour a 1 year warranty on their work. So I’d let them have a go at fixing it again, with a proper gasket this time that is. Everyone can make mistakes It’s how those mistakes are handled which separate the men from the boys.

If they put up a stink, then social media is your friend on whatever fora is relevant. Let us know how it works out. If need be, I’d be happy to give suggestions on where to post your experiences.

[CamE32]

I appreciate the support, guys!

And I agree @whiteghost - they did do the job a 2nd time without any mention of payment, so I'm hoping they once again admit fault and *try* to make it right. If not, that's when I will put them on blast/burn the bridge

Edit: this time I will make a point of requesting they use a proper gasket and basically do it like they did it the first time, just tighten the dang bolts!

[paulmer]

Yep, we've definitely all been here. I'm sure the guys are really kicking themselves. Not tightening bolts is an innocent enough mistake. But then to not apply the sealant correctly, and have it leak..ahh man.

They had to take it back off, so why not just replace the damn gasket? Ouch

[robertjlewis1]

Providing the area where the gasket sits is all properly cleaned up there would be no need for sealant ideally. I get that some people like to use it also as a 'belt and braces' thing but I know from experience sometimes using sealant can actually make things worse. Over use can mean it squeezes out upon compression and risks getting into places it shouldn't and if it is applied too thinly and starts to dry before assembly then the mating surfaces can actually be less in contact.
Just make sure they do the job properly and use the correct gasket this time.
Good luck

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[youngbimmer]

If the mating surfaces are in good condition and cleaned correctly, there should be no use of sealants at all. Just a fresh gasket properly installed and torqued down. The hard part of this job should have been raising the motor, not installing the gasket.

[BFPilgrim]

I agree with the above that sealant should not be required.

Interestingly, as a Brit living in the USA, I’ve noticed it is a trend here for mechanics at shops and DIY guys alike to use sealant for all. Every time I delve into something I haven’t yet removed I waste so much time removing that RTV bollocks and prepping the surfaces.

A good fitting quality gasket on nicely prepped good surfaces won’t leak a drop.

I’m not familiar with the M30 but if it’s a stamped steel oil pan is the flange good and true? If there was a thick gasket and someone has over-torqued it, it usually creates high spots around the bolt holes. I usually sit the flange on something flat and tap the deformations flat again with a wide punch.

Maybe if you let that place do the job again, be there to have a look at the sump/oil pan when it’s off the car, you’ll see by eye if it’s not true.

I know this isn’t a BMW, but just to prove the point, what was a leaky rear diff on my truck, hasn’t dropped a single drop in over a year. It was plastered with RTV and I installed a good quality gasket bone dry on nicely prepped surfaces, torqued to spec.







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[shogun]

1991 e32 735i pan gasket replacement m30 engine http://www.bimmernut.com/forum/showt...ent+m30+engine

[N.///M.Z]

While I have not replaced an M30 Sump gasket in the e32, I can vouch for a gasket using windscreen urethane sealant for the M30 engine. This is my process: Clean the sump and block surfaces removing all old gasket or sealant, run two lines of sealant around the sump surface and circle each bolt hole, place and hand tighten the bolts so that the surfaces are still a couple mm apart, then wait approx. 60-120min before tightening to spec. There are a couple reason for the two stage tightening process. a) the sealant does not squeeze out or into the engine. b) there is sufficient sealant to work c) this provides enough space to pry the sump off the block and you can remove the dang thing again.
The last gasket I completed was still leak free after more than three years, and I only needed to remove the sump when I pulled the engine. IMHO I would not use another solid gasket because I know the Urethane will not fail. https://smitsgroup.co.nz/product/600...-sealant-310ml

[shogun]

check the technical data sheet of that windscreen sealant, temperature resistance is at the limit!
Technical Data Base: Polyurethane, Consistency: Tixothropic Paste, Curing System: moisture cure, Skin Time: ca 25-30 minutes (*), Curing Time: 3.5mm/24hr (*), Hardness: 55+-5 Shore A, Specific Gravity: 1.20 +- 0.02
Temperature Resistance: 30oC until +90oC

Normal M30 engine operating temperature, °C (F), ~90 (195). http://mywikimotors.com/m30b35/

[gidenkidenk]

I did my upper and lower with permatex ultra grey and no factory gasket (don't trust that paper). Then I used blue loc tite on the bolts. Never leaked for 3 years up to selling the car. Your pan might be warped

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[CamE32]

More bad news: the mechanic has my car and claims the oil is not leaking from the pan gasket... supposedly it's leaking from the head gasket

Seems very odd because the engine has less than 100k miles... my first 735 made it to 225k before the head gasket failed. What do you all think?

Maybe it's due to age and the fact that it sat for 12 years before I got it? IDK, but I'm pretty discouraged at the moment.

IF it is the head gasket, should I try re-torquing the head bolts first and foremost? Or go straight to replacement? If at all possible I do not want to do that job a 2nd time in my life... ugh

[Cactuar]

Which side is the oil coming from on the block? It could be dripping from the timing cover or the bolt that holds the crank position sensor.

[robertjlewis1]

My gaskets were quite crispy and brittle on the 750 so I suppose it could be from the head gasket. I think it depends on milage, usage and perhaps how well it's been maintained as to how the gaskets are. If they are like mine were then leaking from anywhere is possible. Did the whole engine out and all gasket replacement overhaul in the end.

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[shogun]

check this, on the M30 that often leaks. quick-fix-for-m30-engine-oil-leak https://www.evansweb.info/2003/02/19...gine-oil-leak/

[N.///M.Z]

+1 this is an annoying leak because the bracket is located in an awkward location to access and is difficult to view. You need to remove the air box, fan shroud, fan as mentioned in the write up and I would recommend also the distributor cap to provide enough access.

[letank]

I did my upper and lower with permatex ultra grey and no factory gasket (don't trust that paper). Then I used blue loc tite on the bolts. Never leaked for 3 years up to selling the car. Your pan might be warped

I cannot stand paper gaskets, it is as antiquated as using leeches to relieve high blood pressure... paper gasket will fail... one of the reason is that the original warranty was for 3 years... so paper does not have to last more than 3 years. Yes, we have paper gasket lasting over 10 years... But most coolant passages are using rubber -except the older jeep have paper, I use silicone grey for aluminum, silicone black for steel and in doubt there is the right stuff... The other factor is that everything is done cheaply... so it is not long lasting, hoses are another big area of contention...

As for differential, I used the whatever RTV I have in the tool box, blue, black, grey.

BTT: as said your pan could be warped around the bolt eyes... or the valve cover gasket is leaking... time for the UV dye, as for the headgasket to leak your coolant will go down, your temp will go up...

[CamE32]

Can’t believe I never updated you all! The oil leak was solved by replacing the oil pressure sensor.

And yes, I agree, the mechanic should’ve noticed that before suggesting a head gasket! I’ve since gone across country without a drop.