[Sarg33]

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I posted this in another thread, but thought it may get more responses if it was its own thread.

(Please correct if I am wrong) From what I have read and understand the typical situation (not money shifts or over revving) is the crank hub slips a little. This throws the timing off and the computer puts the car into limp mode or if it has slipped enough it prevents the car from starting. This is done to prevent any internal engine damage. BMW then has to replace the crank hub, bolt and retime the engine.

Does anyone have an accurate repair bill from BMW when their car has gone into limp mode or not starting from the crank hub slipping? What was replaced/repaired?

That would be the deciding factor for me in any pre-warranty expiration mods. From my understanding we are not talking about total engine replacement just a new crank hub, bolt and re-timing.

[McLaren720s]

One of the repair bills I saw from one of the forum members who had it fixed by BMW was $6700 and it was all out of pocket because they denied his warranty due to being tuned
If you have an independent shop fix it such as SSR Performance, it cost about $4000 and it includes a new crank hub design that supposedly cannot spin.

Depending how bad the crank hub slips, in rare cases it can lead to catastrophic engine failure where the valves hit the pistons.
A used S55 engine is between 10,000 and $13,000 in which case the repair bill is quite ridiculous

Regardless, if you’re out of warranty and plan on keeping the car for a long time, it’s probably a good idea to just have it done. While this has happened to stock cars as well, the rate does seem to higher among tuned cars

There are lots of dealerships who have never seen an M with this problem (including my dealership). I’m not sure how common this really is or is it blown out of proportion. There’s a million M’s out there with the S55 engine. How many of them actually have this issue? 1%? Maybe less?
Of course, one could also argue that they could be denying or playing this down so they won’t scare potential buyers

[M2Cmtl]

BMW is like any other business. They figured it's less expensive to deal with warranty claims than to issue a recall. Like McLaren720s said, many dealer have never even seen this issue...

[Sarg33]

Originally Posted by f31mtl

BMW is like any other business. They figured it's less expensive to deal with warranty claims than to issue a recall. Like McLaren720s said, many dealer have never even seen this issue...

Yes, I agree and from what I have read I personally feel it is blown way out of proportion. I would love to get total numbers of S55 vehicles produced vs total number of crank hub failures. But this topic has been beaten to death and I was simply trying to find out the cost of said failure which McLaren720s answered. So now if I choose to tune I know it could cost me a minimum of $6,700 if something went wrong.

[McLaren720s]

Take a look at this survey of forum members with or without spun crank hub (SCH)

https://f80.bimmerpost.com/forums/po...ts&pollid=9445

[Sarg33]

Originally Posted by McLaren720s

Take a look at this survey of forum members with or without spun crank hub (SCH)

https://f80.bimmerpost.com/forums/po...ts&pollid=9445

Man, this forum has everything. lol Small sampling, but starts to give an overall picture. Thank you

[McLaren720s]

Based on that poll (812 voters) the failure rate does seem to be around 10% with the very large majority of the fails being among modified cars.

I suppose the lesson is this: if you plan on tuning it or it's going out of warranty - it's probably worth getting the crank hub fix.

Otherwise, if you have warranty and you're stock, you're covered.

[Sarg33]

Originally Posted by McLaren720s

Based on that poll (812 voters) the failure rate does seem to be around 10% with the very large majority of the fails being among modified cars.

I suppose the lesson is this: if you plan on tuning it or it's going out of warranty - it's probably worth getting the crank hub fix.

Otherwise, if you have warranty and you're stock, you're covered.

Thank you, I was working the numbers, but people actually wanted me to do work at work? Crazy people.

[robertm]

Ridiculous number of people with engine failure. It will effect resale in the long run.

[McLaren720s]

Originally Posted by robertm

Ridiculous number of people with engine failure. It will effect resale in the long run.

It’s technically still a small sample (812) compared to the all the M2/3/4’s out there worldwide (hundreds of thousands?). When you study a larger pool, those percentages might change significantly.

Still, it does kinda suck but the fact that it happens “mostly” to modified cars, tells us that BMW either did not anticipate this problem when power increases significantly over stock or its simply a design problem. The new S58 engine has an integrated crank hub that cannot spin so maybe that’s their way of acknowledging the problem.

This is also more common in cars with DCT and the lightning quick changes in rotational torque due to the aggressive downshifting of the DCT is suspected.

[chris719]

Originally Posted by robertm

Ridiculous number of people with engine failure. It will effect resale in the long run.

It might. I think it definitely affected the resale of the V10 M5 (S85 rod bearing issue). It might have affected the E92 M3 resale also but not quite as much.

This problem isn't as widespread, expensive, or inevitable as the S85 and S65 rod bearing failures though.

[Beemerm3]

The steps to removing a crank hub is the same as changing your timing chain. Just put on a cbc on it. It’s better insurance.