Flywheel failure at 45K miles

Kootenay135i · 08-04-2021, 12:24 PM

I am baffled that my e82 n55 DCT 135i with 45K miles on it needs a new flywheel. I have never needed a new flywheel on any performance vehicle that I've owned.

It seems so early in the vehicle's lifespan to have to change this part. So I guess it leave me with two questions:

1) Anyone else have to replace one of these flywheels early?

2) What causes this part to fail?

dtla1 · 08-04-2021, 12:37 PM

Quote:

Originally Posted by JonChester

I am baffled that my e82 n55 DCT 135i with 45K miles on it needs a new flywheel. I have never needed a new flywheel on any performance vehicle that I've owned.

It seems so early in the vehicle's lifespan to have to change this part. So I guess it leave me with two questions:

1) Anyone else have to replace one of these flywheels early?

2) What causes this part to fail?

#2 is what I'm interested in. What specifically did they (who is the "they" btw?) tell you is wrong with it?

mr.fabulous · 08-09-2021, 10:13 PM

Mine has sounded like marbles in a coffee can for as long as I've owned this car (nearly seven years, not many miles 35K). What exactly "failed"?

Kootenay135i · 08-10-2021, 08:40 AM

Independent mechanic dropped the transmission out of my car to fix DCT leaks on top of the trans. He showed me that the flywheel had been slowly leaking grease and had a lot of play, and said those two factors indicated the flywheel had failed.

Looking around on the web does validate my mechanic: "There are symptoms of BMW DMF failure .. excessive play between the two halves of the DMF (if the outer flywheel section can rotate more than 20mm in either direction), and grease leaking out from inside the flywheel assembly. A worn DMF does not just impact performance or clutch operation, it's a big safety issue as well. A DMF that breaks apart can be catastrophic to the transmission as well as dangerous to the driver and passenger."

So I am comfortable that my flywheel needs replacement, but it seems so early in the vehicle's lifespan that I'm wondering why. This car is new to me, which is why I'm interestred in the root cause. The car only has accumulated 45K miles in 10 years. My mechanics theory is that if the cars sit for long periods of time the seals can dry out, crack and then leak. Seems reasonable.

Part number is 21207590853 (Dual Mass Flywheel)

MGalo · 08-10-2021, 04:01 PM

OP, are the only owner the car has had, or...? I have an '11 E88 135i DCT that had 56,2xx miles 2-17-21, now has 59,8xx miles, and am the 5th or 6th owner...with no apparent gremlins.

Thank you for any info and updates.
Good luck!

wdb · 08-11-2021, 10:30 AM

I replaced the DMF in my Z4MC at ~80K miles. It had about enough play to qualify as "worn" but was otherwise fine. But I was in there anyway. I can't offer any insights into what might have accelerated the demise of your flywheel but my mind immediately goes to abusive levels of clutch engagement. That might show up in other parts of the drivetrain as well.

Kootenay135i · 08-11-2021, 06:33 PM

Quote:

Originally Posted by MGalo

OP, are the only owner the car has had?

No, I am the third owner. But the first owner put less than 5K miles per year on the car for the first six years. This 10-year old vehicle looks to have been treated gently - low mileage, dealer-serviced and very clean inside and out.

dtla1 · 08-12-2021, 10:35 AM

Quote:

Originally Posted by Kootenay135i

No, I am the third owner. But the first owner put less than 5K miles per year on the car for the first six years. This 10-year old vehicle looks to have been treated gently - low mileage, dealer-serviced and very clean inside and out.

I guess the lesson is that the DMF needs an "Italian tune-up" every once in a while to stay agile?

Samuel Wikerson · 08-29-2021, 07:01 AM

Stuff fails due to abuse, neglect, or poor design. Checking around on the net, flywheel failures appear to be rare, so I would suspect abuse.

DCTs have had problems with leaks, stalling, and surging issues. The stalling or surging could have put an extra load on the flywheel. Of course, it all depends upon how the previous owners responded to the problem.

My transmission had all three of them, so during the mfg's warranty, I had the transmission pulled to fix the leaks and reprogrammed to cure the stalling and surging. I suspect many owners ignored these problems and just lived with them. They probably dumped the car which can account for multiple owners.

I also suspect that some owners ignored some of the factory recalls. For example, mechanics have found the bolts that hold on the camshaft gears in the oil pan. BMW had a recall to replace them.

These N55 & N54 engines are ticking time bombs for owners who don't regularly service their cars. This is especially true for owners who aren't aware of the car's big trouble spots. The OFHG leaking is number one followed by the pulleys on the serpentine belt tensioner failing. These can cause the belt to be sucked into the crankcase and tangled up in the oil pump starving the engine of oil and catastrophe.

Notice in the video the subframe has to be dropped to remove the oil pan. This is expensive, but if you have xDrive, you might need a bank loan! There is a company that makes a cover to protect the crankshaft seal, but a better idea is to fix oil leaks.

I have found a simple method to detect oil leaks. When you change the engine oil, make sure you fill it up to the max level. From time-to-time check the oil level. If you see it fall from the max level just a tiny bit, you have a leak. Of course, if you have an oil burner, this won't work.

08-04-2021, 12:24 PM	#1
Kootenay135i New Member 0 Rep 14 Posts Drives: 2012 BMW 135i N55 Join Date: Jun 2021 Location: British Columbia, Canada iTrader: (0)	Flywheel failure at 45K miles I am baffled that my e82 n55 DCT 135i with 45K miles on it needs a new flywheel. I have never needed a new flywheel on any performance vehicle that I've owned. It seems so early in the vehicle's lifespan to have to change this part. So I guess it leave me with two questions: 1) Anyone else have to replace one of these flywheels early? 2) What causes this part to fail?
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08-09-2021, 10:13 PM	#3
mr.fabulous Captain 212 Rep 893 Posts Drives: Women Crazy Join Date: Dec 2014 Location: Florida Gulf Coast iTrader: (0)	Mine has sounded like marbles in a coffee can for as long as I've owned this car (nearly seven years, not many miles 35K). What exactly "failed"? __________________ 2011 135i MSport 6MT AW/black, 72Kmiles, bone stock, moneymoneymoneymoneymoneymoneymoneymoneymoneymoney I LOVE THIS CAR
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08-10-2021, 08:40 AM	#4
Kootenay135i New Member 0 Rep 14 Posts Drives: 2012 BMW 135i N55 Join Date: Jun 2021 Location: British Columbia, Canada iTrader: (0)	Independent mechanic dropped the transmission out of my car to fix DCT leaks on top of the trans. He showed me that the flywheel had been slowly leaking grease and had a lot of play, and said those two factors indicated the flywheel had failed. Looking around on the web does validate my mechanic: "There are symptoms of BMW DMF failure .. excessive play between the two halves of the DMF (if the outer flywheel section can rotate more than 20mm in either direction), and grease leaking out from inside the flywheel assembly. A worn DMF does not just impact performance or clutch operation, it's a big safety issue as well. A DMF that breaks apart can be catastrophic to the transmission as well as dangerous to the driver and passenger." So I am comfortable that my flywheel needs replacement, but it seems so early in the vehicle's lifespan that I'm wondering why. This car is new to me, which is why I'm interestred in the root cause. The car only has accumulated 45K miles in 10 years. My mechanics theory is that if the cars sit for long periods of time the seals can dry out, crack and then leak. Seems reasonable. Part number is 21207590853 (Dual Mass Flywheel)
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08-10-2021, 04:01 PM	#5
MGalo New Member 15 Rep 25 Posts Drives: '11 E88 135i, ToyotaMR2Spyder Join Date: Mar 2021 Location: Indy iTrader: (0)	OP, are the only owner the car has had, or...? I have an '11 E88 135i DCT that had 56,2xx miles 2-17-21, now has 59,8xx miles, and am the 5th or 6th owner...with no apparent gremlins. Thank you for any info and updates. Good luck!
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08-11-2021, 10:30 AM	#6
wdb dances with roads 4754 Rep 4,100 Posts Drives: '07 E86, '02 996, '95 Seven Join Date: Jul 2015 Location: the perimeter iTrader: (4)	I replaced the DMF in my Z4MC at ~80K miles. It had about enough play to qualify as "worn" but was otherwise fine. But I was in there anyway. I can't offer any insights into what might have accelerated the demise of your flywheel but my mind immediately goes to abusive levels of clutch engagement. That might show up in other parts of the drivetrain as well.
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08-29-2021, 07:01 AM	#9
Samuel Wikerson Private 8 Rep 56 Posts Drives: BMW 135i M Sport Join Date: Jan 2021 Location: Dayton, Ohio iTrader: (0)	Stuff fails due to abuse, neglect, or poor design. Checking around on the net, flywheel failures appear to be rare, so I would suspect abuse. DCTs have had problems with leaks, stalling, and surging issues. The stalling or surging could have put an extra load on the flywheel. Of course, it all depends upon how the previous owners responded to the problem. My transmission had all three of them, so during the mfg's warranty, I had the transmission pulled to fix the leaks and reprogrammed to cure the stalling and surging. I suspect many owners ignored these problems and just lived with them. They probably dumped the car which can account for multiple owners. I also suspect that some owners ignored some of the factory recalls. For example, mechanics have found the bolts that hold on the camshaft gears in the oil pan. BMW had a recall to replace them. These N55 & N54 engines are ticking time bombs for owners who don't regularly service their cars. This is especially true for owners who aren't aware of the car's big trouble spots. The OFHG leaking is number one followed by the pulleys on the serpentine belt tensioner failing. These can cause the belt to be sucked into the crankcase and tangled up in the oil pump starving the engine of oil and catastrophe. Notice in the video the subframe has to be dropped to remove the oil pan. This is expensive, but if you have xDrive, you might need a bank loan! There is a company that makes a cover to protect the crankshaft seal, but a better idea is to fix oil leaks. I have found a simple method to detect oil leaks. When you change the engine oil, make sure you fill it up to the max level. From time-to-time check the oil level. If you see it fall from the max level just a tiny bit, you have a leak. Of course, if you have an oil burner, this won't work.
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