who is still on original rod bearings?

[richinvan]

100k mi, original bearings.

[davesaddiction]

Originally Posted by richinvan

100k mi, original bearings.

Milestone. Nice!

[chili555]

2011 DCT with 37k. Original bearings.

[steven747]

92k and original bearing e92 m3 08

[CIFUM3]

I got up to 64k before I swapped my bearings.
Only did it for peace of mind and because I'm installing supercharger soon

[azndrunk74]

09 92k miles on original bearings. No issues according to Blackstone.

[redpriest]

Any track time for those with high mileage and on original bearings?

[Ezio]

I would probably never change them.

[SenorFunkyPants]

Originally Posted by redpriest

Any track time for those with high mileage and on original bearings?

Firstly this is a scatter graph of the 55 (non supercharged) engine failures reported on M3post.



Whats worth noting is that once you have passed 50-60K miles the trend is for less failures...ie if you were unlucky enough to be in the 1 to 1.5% of owners to have a car with some sort of bearing clearance problem it will tend to fail at relatively low miles.

The other factor is how you use the car.
Anything that puts a high load on the engine will tend to put a high load on the bearings. Such as supercharging, aggressive ECU tune, tracking etc.
If you are mechanically sympathetic with you car, warm it up carefully, no high revs with cold or very hot oil etc then there is every reason to be optimistic.

[davesaddiction]

Originally Posted by SenorFunkyPants

Whats worth noting is that once you have passed 50-60K miles the trend is for less failures...ie if you were unlucky enough to be in the 1 to 1.5% of owners to have a car with some sort of bearing clearance problem it will tend to fail at relatively low miles.

The other factor is how you use the car.
Anything that puts a high load on the engine will tend to put a high load on the bearings. Such as supercharging, aggressive ECU tune, tracking etc.
If you are mechanically sympathetic with you car, warm it up carefully, no high revs with cold or very hot oil etc then there is every reason to be optimistic.

Thanks, Funky. What does the X-axis represent? As I'm approaching 75k, it's encouraging to think that I may be in the clear, but I guess more data is required to say anything with certainty. But I do like my odds, at least. Hopefully that 1-2% failure rate proves to be true long term.

But I definitely don't baby it... I'm sure to let her warm up, but then I use the car the way it was meant to be. Not sure how aggressive my tune is, but I do track her once in a while, and definitely wind the engine out every chance I get!

[SenorFunkyPants]

The X axis is loosely related to year of manufacture...I put it together quite quickly but generally 0 is the oldest. I tried to make the x axis the year of manufacture but it didn't come out as clear as I wanted.
It is true though that newer cars to the right will tend to have lower miles but there is no obvious trend that shows that early cars fail at a higher rate with increasing miles...which you might expect.

Its a guessing game trying to quantify what might be a factor in engine wear:
but I'd say:
High revs with oil cold or very hot.
Total time spent at or near the rev limit.
low octane fuel especially with high ambient air temp.

[Rupes]

Originally Posted by SenorFunkyPants

Whats worth noting is that once you have passed 50-60K miles the trend is for less failures...ie if you were unlucky enough to be in the 1 to 1.5% of owners to have a car with some sort of bearing clearance problem it will tend to fail at relatively low miles.

Don't you think it's more accurate to state that the newer cars don't have as many miles on them and that's the reason for less faults at higher mileage? After all, this theory doesn't exactly hold true with 08 models according to your graph.

[SenorFunkyPants]

This is just 2007-2010 incl cars:



I would have thought that the prediction would be: as cars get older with higher mileages they would be more likely to fail.
Yet this does not appear to be the case.
Anyway...I was just trying to be reassuring...I don't want to start yet another argument about it.

[davesaddiction]

Originally Posted by SenorFunkyPants

I would have thought that the prediction would be: as cars get older with higher mileages they would be more likely to fail.
Yet this does not appear to be the case.
Anyway...I was just trying to be reassuring...I don't want to start yet another argument about it.

Thanks for the reassurance! Since so many of the failures happen at such a relatively low mileage, it does give those of us approaching 100k some confidence that we don't necessarily have a "ticking time bomb" under our right foot.

I may still proactively change out my bearings at some point in the future, but I'm definitely doing the wait-and-see approach at this point. The more people who have them swapped out and share the condition of theirs, and any additional failures going forward should all add necessary data to determine the true cause and best course of action to ensure the long-term longevity of our engines.

[imserious]

Originally Posted by SenorFunkyPants

This is just 2007-2010 incl cars:

What is the X axis? perhaps number of known incidents? For context it would be helpful to list estimated # of total cars produced during the sample period.

[davesaddiction]

Originally Posted by imserious

What is the X axis?

Originally Posted by davesaddiction

What does the X-axis represent?

Originally Posted by SenorFunkyPants

The X axis is loosely related to year of manufacture...I put it together quite quickly but generally 0 is the oldest. I tried to make the x axis the year of manufacture but it didn't come out as clear as I wanted.

Reading is

[imserious]

reading fail on my part.

it would be interesting to do an analysis based on known variables such as year, climate, supercharged, mileage, typical usage, etc. but in the end it may not be statistically significant.

anyways, interesting info. thanks for posting!

i say warm it up, keep the oil fresh and run these cars hard! i need to do more of the latter myself.

[Jettt]

08 with 200,000km They are being replaced as I type.

[davesaddiction]

Originally Posted by Jettt

08 with 200,000km They are being replaced as I type.

Please post pictures of the old ones. Thanks.

[Groundpilot]

Originally Posted by SenorFunkyPants

Firstly this is a scatter graph of the 55 (non supercharged) engine failures reported on M3post.



Whats worth noting is that once you have passed 50-60K miles the trend is for less failures...ie if you were unlucky enough to be in the 1 to 1.5% of owners to have a car with some sort of bearing clearance problem it will tend to fail at relatively low miles.

The other factor is how you use the car.
Anything that puts a high load on the engine will tend to put a high load on the bearings. Such as supercharging, aggressive ECU tune, tracking etc.
If you are mechanically sympathetic with you car, warm it up carefully, no high revs with cold or very hot oil etc then there is every reason to be optimistic.

Good post

[JD3]

As promised. Changed at 71K. I could've easily said "71K, no issues" before last week. This one, 7, was the worst. Others showed nothing major, others showed wear. This one was the worst though.

[marksae]

JD3, how were your recent blackstone reports?