Over-tightened drain plug = $3200 repair?!

[SG11M3]

Ok, I'm having a bit of a panic moment. I recently bought a pristine 2011 E93 M3 with a good service history and 40k miles. All is fine, it works great and I've had no issues...until now. It was due for a brake fluid service so I took it in to a local BMW dealership (Omaha, NE) and told them to change the oil as well.

I get a call a couple hours later and they tell me it's leaking my new oil at a steady rate and after investigating further they tell me the drain plug was torqued too tight (previous owner/shop) which damaged the oil pan and now they can't get a good seal. He then asked me if I was sitting down because the only way to fix the issue is a new oil pan which is 8.4 hours of work and a $1,700 part. Any advice? Are they correct? I have a wedding in 3 months and this has me furious at the moment....please help!

Thanks!

-Mitch

[Visceral]

To be honest I just spent $3100 replacing my oil pan after I stripped the bolt. As the only bonus, I got an oil pan from Bimmerworld that had an actual dipstick. $1700 is retail, BTW. Even Bimmerworld sells it for considerably less.

That said, it leaked *immediately* after. The pan (and the threads) is an aluminum part and is super soft. I don't think a previous owner did it. I think they just did it and they are trying to pin it on someone else.

Either the bolt was stripped and it leaked before OR the bolt wasn't stripped and they just stripped it (and now it leaks).

[Visceral]

They also couldn't have finished the job and filled it with new oil without noticing that the threads were stripped even if the last owner had done it. The bolt wouldn't have torqued.

[SG11M3]

Yeah, it didn't leak at all before I took it in. You think it's their fault then? I'm sure they'd fight me hard on that one.

[eatsleepboost]

This seems to be fairly common unfortunately. I suggest a time-sert.

See thread..
https://www.m3post.com/forums/showth...&highlight=Pan

[SG11M3]

Originally Posted by Visceral

They also couldn't have finished the job and filled it with new oil without noticing that the threads were stripped even if the last owner had done it. The bolt wouldn't have torqued.

They said over-tightened, not stripped but I'm wondering exactly what that looks like on the pan/threads themselves. Thanks for your input!

[UPSROD]

Search Time- Sert oil pan repair.

[roastbeef]

Originally Posted by Visceral

They also couldn't have finished the job and filled it with new oil without noticing that the threads were stripped even if the last owner had done it. The bolt wouldn't have torqued.

This. These things don't leak until they are reallllllly loose. Dude probably blasted it on and tried to pretend it wasn't his doing.

[SG11M3]

Originally Posted by eatsleepboost

This seems to be fairly common unfortunately. I suggest a time-sert.

See thread..
https://www.m3post.com/forums/showth...&highlight=Pan

Thanks! Reading through that thread now.

[drrust]

The timesert repair takes some care to make sure that it is square/flush to the pan. Other methods include using a an oversized plug.

I agree that the dealership did not hand tighten and torque the plug as they would have felt the threads not catch. (A very bad feeling!) They wouldn't have added oil if the proper procedure was used.

I'll put my two cents in on another possible cause. Aluminum is also know for fretting. This is where small movements cause breaks in the oxide film on the aluminum. This leads to micro welds between the plug and pan. If one looks inside the pan, the main drain plug doesn't have a full 'ring' all the way up. There are cut outs to allow the oil to drain out. This could lead to some different thermal stresses as the temperatures vary.

[MaximusB]

Sounds like they stripped it and trying to put the blame else where. Whether or not the previous owner stripped it have nothing to do with you. From your perspective your car wasn't leaking a drop of oil before you took it in, correct? And now it is after the dealer serviced it, correct? So I would simply ask the dealer why it is now "leaking at a steady rate" when it clearly wasn't before you took it in.

And yes replacing the pan is very time consuming. If you are going to replace the pan then you should consider replacing the rod bearings since they are literally right there once you drop the pan.

[Grip Addict]

This happened to me.

My father in law (a career mechanic) drilled/input a new thread that the oil bolt actually can grab.

I would not recommend anyone attempting it who has no idea what they are doing though.

[GotV8?]

I would challenge the SA at the dealership and make it a point that it did not leak at all before the service tech did oil change and service the car, considering when the car is on the lift, the first thing they would have notice is any leaks from underneath the car would have been evident and visible. Sounds like you are getting screwed by a mechanic's negligence!! goodluck, hope there are still some honest people out there...i.e. the one who work on the car has a 'heart".

[fred340]

Originally Posted by GotV8?

I would challenge the SA at the dealership and make it a point that it did not leak at all before the service tech did oil change and service the car, considering when the car is on the lift, the first thing they would have notice is any leaks from underneath the car would have been evident and visible. Sounds like you are getting screwed by a mechanic's negligence!! goodluck, hope there are still some honest people out there...i.e. the one who work on the car has a 'heart".

I don't want to be the devils advocate, but sometimes you cannot know the threads are damaged until you start unscrewing the drain plug. Once the thread are coming out with the drain plug, you know it's too late.
Usually the technicians at the dealer carry a 1/2, 3/8 and 1/4 torque wrench in their tool box. If they dont have good torque wrenches they dont belong there and they shouldn't work on german cars. They should go work at Midas.
Alway try to get the petrolhead who works at your dealer, he will take good care of your ///M.

[buddalun]

I literally got the call yesterday that my oil pan is stripped and that the bolt cannot be torqued to spec. I had the choice to spend $2800 on a new BMW pan and labor, or try the Time-Sert. I chose the Time-Sert since so many members here had had good long-term luck with them. The pan is still coming off since the Time-Sert will be put in by a separate machine shop.

Since the pan is coming off, I am doing the rod bearings and bolts as well. A little job (oil change and a few other tidbits), made for an eye-watering bill. Regardless, the soft aluminum pan, and the steel drain bolt certainly are not the best pairing.

I think the ultimate solution would be to have the bung re-welded with a steel thread, and then to be careful and only use hand tools and proper torque specs thereafter.

[pbonsalb]

It is unfortunate incompetent work is done that costs the owner or subsequent owners so much money to fix.

[deansbimmer]

In your situation I would challenge their tech’s assertion that it was already damaged.

I would also have a better independent shop do the work. Either Time-Sert it, or replace the pan but do rod bearings at the same time.

[svinfinity]

Just use a time-sert. I did mine on jack stands very carefully and came out stronger than oem.

[Timujin]

I am calling BS.

[Scharbag]

Aluminum pans scare me. Torque wrench every time. Too many techs over tighten drain plugs on steel pans too. At least they are harder to strip. Still, no excuse for poor workmanship.

Time-sert is a great option and CAN be done with the pan in the car by a competent tech. But as others have said, great time to drop the pan and do the rod bearings. When the pan is off, install a time-sert.

If I were you, I would check the other pan plug for signs of damage too.

[Agent-GHQ]

From my last free oil change at the stealership (4yr maintenance free), I DIY my oil change and I noticed one of the two oil drain plug was significantly tighter than the other. This is clearly an indicator that the tech either over tighten the drain plug or did not properly tighten it with a torque wrench. I mean you can start of by tighten the drain plug with your hands and once it starts to tighten then turn about a quarter to avoid tension point.


I suspect they cut corners on and tried to cover their asses. I'd strongly challenge them and give them a good fight before coughing up that kind of mullah for repair.

[pbonsalb]

The fault is hard to prove unless the oil was always changed at the same shop. If other shops changed the oil, one of them could be at fault. It could have been partially stripped but not leaking for years.

Find an independent shop who will time sert it on the car or if you were going to do rod bearings then pull the pan and time sert or weld it off the car and do rod bearings at the same time since there is significant labor overlap in pulling the pan and doing bearings.