# 91,000 miles, no CBU, still averages 32 mpg...wtf?



## totitan (May 11, 2013)

n1das and Hooper.....since your both over 100K I was wondering if either of you have had to replace the crank dampener? Im about to go on a road trip to CO and back and dont know whether to be worried about that or not.


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## Hoooper (Jun 17, 2013)

I havent had to replace it. Im waiting for the fluidampr to come out. Once thats out, ill do a preventative replacement.


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## n1das (Jul 22, 2013)

DubVBenz said:


> Are the F10 N57 535ds even known to be susceptible? I haven't heard of any of them with CBU.


I recall reading about one case here a while ago. It might have been in a '14 or '15 X5 35d instead of a 535d. The engine had an alarmingly high amount of CBU for so low miles. The car was never driven hard at all and was used exclusively for short trips. That poor engine never saw any boost and probably was never run long enough to fully reach operating temperature.


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## n1das (Jul 22, 2013)

totitan said:


> n1das and Hooper.....since your both over 100K I was wondering if either of you have had to replace the crank *dampener*? Im about to go on a road trip to CO and back and dont know whether to be worried about that or not.


I have never had to replace it due to it getting "wet" (dampener i.e., something used to get something wet vs. damper i.e. something used to smooth out). 

No issues, never had to replace it.

Good luck.


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## Flyingman (Sep 13, 2009)

n1das said:


> I have never had to replace it due to it getting "wet" (dampener i.e., something used to get something wet vs. damper i.e. something used to smooth out).
> 
> No issues, never had to replace it.
> 
> Good luck.


I believe it s called the torsional damper. It may give you a short warning, perhaps power steering skips a beat or you get an alternator light, but once it goes you need to get to a shop.

If I had 100k I'd pre-empt it. Mine failed at about 75k miles as I recall.


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## totitan (May 11, 2013)

Flyingman said:


> I believe it s called the torsional damper. It may give you a short warning, perhaps power steering skips a beat or you get an alternator light, but once it goes you need to get to a shop.
> 
> If I had 100k I'd pre-empt it. Mine failed at about 75k miles as I recall.


Damn...I probably should have but in two hours Im about to leave on a road trip from Thousand Oaks to Denver and back. Hopefully it will stay in one piece until I get back.


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## Hoooper (Jun 17, 2013)

That's pretty much my hope to. I am hoping it lasts until the new fluidampr is released so that I don't have to buy a replacement that is more expensive and less durable than another part that is coming to the market.

Sent from my SAMSUNG-SM-G890A using Tapatalk


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## Doug Huffman (Apr 25, 2015)

How do you think that you know the durability of a product in an untried application?


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## n1das (Jul 22, 2013)

Flyingman said:


> I believe it s called the torsional damper. It may give you a short warning, perhaps power steering skips a beat or you get an alternator light, but once it goes you need to get to a shop.
> 
> If I had 100k I'd pre-empt it. Mine failed at about 75k miles as I recall.


I think if mine were to fail, the warning signs likely would start happening at high revs when I've got my foot into to it to help prevent CBU. My daily WOT runs when getting onto a highway take the engine up to at least 4000 RPM before each shift.

Thanks for the heads up.


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## totitan (May 11, 2013)

n1das said:


> I think if mine were to fail, the warning signs likely would start happening at high revs when I've got my foot into to it to help prevent CBU. My daily WOT runs when getting onto a highway take the engine up to at least 4000 RPM before each shift.
> 
> Thanks for the heads up.


I drove 686 miles today in eight hours. Hopefully that blew some carbon out...


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## 335dFan (Nov 8, 2012)

totitan said:


> I drove 686 miles today in eight hours. Hopefully that blew some carbon out...


Probably not much. RPMs were probably about 2,500 or so most of the time.


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## totitan (May 11, 2013)

335dFan said:


> Probably not much. RPMs were probably about 2,500 or so most of the time.


I did spend a lot of time at 100 pulling hard between 5-7000 ft elevation. I think it got a good workout


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## Hoooper (Jun 17, 2013)

Doug Huffman said:


> How do you think that you know the durability of a product in an untried application?


I dont. We do know the durability of the stock one isnt great, and we know fluidampr makes an excellent long lasting product for a heck of a lot of applications so Im inclined to trust one of the most tested manufacturers of dampers in the world over a damper that is known to be weak


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## 335dFan (Nov 8, 2012)

totitan said:


> I did spend a lot of time at 100 pulling hard between 5-7000 ft elevation. I think it got a good workout


Sounds like my kinda fun road trip.


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## Flyingman (Sep 13, 2009)

335dFan said:


> Probably not much. RPMs were probably about 2,500 or so most of the time.


I would expect the turbo working harder would help more so than rpms.


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## Doug Huffman (Apr 25, 2015)

Hoooper said:


> I dont. We do know the durability of the stock one isnt great, ...


You do not know the durability of any but self-reported failures. Non-failures are not reported and the vast majority of failures are not reported.

Fan forums are of self-selected participants and not representative of the entire population.


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## Hoooper (Jun 17, 2013)

There are far more failures of this damper than all the other platforms I am familiar with combined, to you that might not be enough evidence but to me that's plenty of evidence to gauge the durability. You can choose to ignore anecdotal evidence and pray that BMW publishes the failure rate of a damper, or you can replace it with one from a company that has a track record of solving other companies failing dampers. The choice is yours and really I couldn't care less which choice you make.


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## Flyingman (Sep 13, 2009)

Doug Huffman said:


> You do not know the durability of any but self-reported failures. Non-failures are not reported and the vast majority of failures are not reported.
> 
> Fan forums are of self-selected participants and not representative of the entire population.


Ahh, but BMW surely knows how many they have replaced!


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## Flyingman (Sep 13, 2009)

Doug Huffman said:


> How do you think that you know the durability of a product in an untried application?


Usually by modeling, FEA, etc..., would be my guess. But what do I know!:dunno:


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## Aufgeblassen (May 25, 2016)

My son remove the intake for our 1998 Jetta TDI for a 1st time cleaning at around 200,000 miles, and it was not all that dirty. :thumbup:


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