[doughboy]

Originally Posted by chris719

I suppose it depends on the coefficient of thermal expansion of the washer vs the rest of the metal.

Yes indeed, in couldn't spell coefficient that late at night

[bimmerdriver2]

Originally Posted by M3R1

Only BMW knows how big of a problem it really is. I am a firm believer that since BMW changed the design in the B58/S58, the problem is real. Again, yes the occurrence is small, so it is an individual decision.

With regards to the first sentence, I don't think there's any question that BMW knows how big of a problem the crank hub really is and like all of the other similar design problems in the past (e.g., S54 VANOS, E46 M3 RACP, etc.), we will never find out what they know unless someone leaks internal information. BMW seems to be good at keeping a lid on things like this, so I doubt we will ever know.

With regards to the second sentence, I don't agree. The B58/S58 has a completely different design and I really doubt it was changed because of the problems with the N55/S55 crank hub. BMW could have relatively easily fixed the crank hub problem by incorporating a key or a pinned design like the various aftermarket solutions. They probably didn't do that because it would have called attention to the design defect and then they would have faced a potential recall. I think it's not unreasonable to speculate that the crank hub has a two-piece design to simplify assembly. Had the block been designed with a removable timing cover, there would have been no reason to have a removable crank hub. They fcuked up when they designed the N55/S55, just like the other times they fcuked up in the past.

[M3R1]

Originally Posted by bimmerdriver2

With regards to the first sentence, I don't think there's any question that BMW knows how big of a problem the crank hub really is and like all of the other similar design problems in the past (e.g., S54 VANOS, E46 M3 RACP, etc.), we will never find out what they know unless someone leaks internal information. BMW seems to be good at keeping a lid on things like this, so I doubt we will ever know.

With regards to the second sentence, I don't agree. The B58/S58 has a completely different design and I really doubt it was changed because of the problems with the N55/S55 crank hub. BMW could have relatively easily fixed the crank hub problem by incorporating a key or a pinned design like the various aftermarket solutions. They probably didn't do that because it would have called attention to the design defect and then they would have faced a potential recall. I think it's not unreasonable to speculate that the crank hub has a two-piece design to simplify assembly. Had the block been designed with a removable timing cover, there would have been no reason to have a removable crank hub. They fcuked up when they designed the N55/S55, just like the other times they fcuked up in the past.

I think we are agreeing here. All I am saying is that it was not a good design. Without the CH issue the engine is great.

I believe the S58 will go down as the best I6 engine, it makes unbelievable power and yet problem free. The finally got an engine that is completely sorted. Too bad all of the cars they put it in are huge.

[AlpsRider]

Originally Posted by M3R1

I think we are agreeing here. All I am saying is that it was not a good design. Without the CH issue the engine is great.

I believe the S58 will go down as the best I6 engine, it makes unbelievable power and yet problem free. The finally got an engine that is completely sorted. Too bad all of the cars they put it in are huge.

The S58 seems to be a great engine. I do prefer the low end torque in the S55. Also, when the time comes to do maintenance on the timing chain if the S58 at the back of the engine it won't be cheap.

[chris719]

Originally Posted by AlpsRider

The S58 seems to be a great engine. I do prefer the low end torque in the S55. Also, when the time comes to do maintenance on the timing chain if the S58 at the back of the engine it won't be cheap.

Rear timing doesn't bother me much. You shouldn't really have to touch the components in theory, and it's not exactly a fun day at the beach for S55 already even though it's in the front. If the chain or guides turns out to be like N20 then sure, it'll be terrible.

[m2ss]

Originally Posted by M3R1

Without the CH issue the engine is great.

I agree here, the question is will they all fail in time...

[M3R1]

Originally Posted by AlpsRider

The S58 seems to be a great engine. I do prefer the low end torque in the S55. Also, when the time comes to do maintenance on the timing chain if the S58 at the back of the engine it won't be cheap.

I love my S55, that is why my CH is one pc now...

Originally Posted by m2ss

I agree here, the question is will they all fail in time...

Time will certainly tell..

[///MPhatic]

Originally Posted by AlpsRider

The S58 seems to be a great engine. I do prefer the low end torque in the S55.

What low-end torque would that be?

[chris719]

Originally Posted by M3R1

I love my S55, that is why my CH is one pc now...



Time will certainly tell..

Which CH did you go with?

[bimmerdriver2]

Originally Posted by M3R1

I think we are agreeing here. All I am saying is that it was not a good design. Without the CH issue the engine is great.

I believe the S58 will go down as the best I6 engine, it makes unbelievable power and yet problem free. The finally got an engine that is completely sorted. Too bad all of the cars they put it in are huge.

Agreed, the crank hub is not a great design, but it's not a show-stopper. Even with the crank hub issue, the S55 seems to be a pretty solid engine. The S58 is an incremental improvement in many ways, but I'm not fond of the timing chain being at the back end of the block.

[bimmerdriver2]

Originally Posted by chris719

Rear timing doesn't bother me much. You shouldn't really have to touch the components in theory, and it's not exactly a fun day at the beach for S55 already even though it's in the front. If the chain or guides turns out to be like N20 then sure, it'll be terrible.

Yup, BMW engines don't exactly have a history of never needing maintenance on the timing components (e.g., S54 VANOS). Chain guides are plastic, so they won't last forever, even if there are no other problems, which is a big if.

[M3R1]

Originally Posted by chris719

Which CH did you go with?

Gintani

[M3R1]

Originally Posted by bimmerdriver2

Agreed, the crank hub is not a great design, but it's not a show-stopper. Even with the crank hub issue, the S55 seems to be a pretty solid engine. The S58 is an incremental improvement in many ways, but I'm not fond of the timing chain being at the back end of the block.

As good as the S58 is, a stage 2 S55 is ferocious in a F87 chassis. There is no need for more. Yes, once the crank hub is addressed you can do bigger turbos, but for the street there is just no need for more.

Perhaps the power of the S58 was necessary in the G8x cars because they weigh more?

[M2_MEDUSA]

Originally Posted by Reddevils7

How hard had you driven on the last drive before you started it up again? Shame it happened but glad you're back up and running again. What aftermarket solution did you go with?

Came from work, commuted. Didnt drive hard at all. I went with the Vargus spline lock solution as that for me made the most logical engineering sense. Its also the easiest on your wallet in terms of labor. Also there have been no failures with the combined spline lock and cbc solution. Been over a year and I abuse it.

[chris719]

Originally Posted by M2_MEDUSA

Came from work, commuted. Didnt drive hard at all. I went with the Vargus spline lock solution as that for me made the most logical engineering sense. Its also the easiest on your wallet in terms of labor. Also there have been no failures with the combined spline lock and cbc solution. Been over a year and I abuse it.

Check your CBC for rusty or damaged bolts. See the thread on the F80/F82 forum. While the spline lock seems solid, their CBC bolts seem suspect.

[AlpsRider]

Originally Posted by chris719

Rear timing doesn't bother me much. You shouldn't really have to touch the components in theory, and it's not exactly a fun day at the beach for S55 already even though it's in the front. If the chain or guides turns out to be like N20 then sure, it'll be terrible.

Yeah, timing chain issues are a PITA. I had an Audi 80 with the v6. It had a timing belt which needed to be changed at about 110k kms. It snapped just before the due mileage. Valves and cylinders kissed and made a mess. It wasn't a cheap repair. This was my lesson to always do timing belt/chain maintenance well in advance of recommendations. I've read that the recommendations for timing chain replacement on BMW engines is around 80k to 110k miles.

[doughboy]

Originally Posted by AlpsRider

Yeah, timing chain issues are a PITA. I had an Audi 80 with the v6. It had a timing belt which needed to be changed at about 110k kms. It snapped just before the due mileage. Valves and cylinders kissed and made a mess. It wasn't a cheap repair. This was my lesson to always do timing belt/chain maintenance well in advance of recommendations. I've read that the recommendations for timing chain replacement on BMW engines is around 80k to 110k miles.

I don't think they're ever meant to be changed, that's the whole point with chain v belt.

They are not a service item.

Certainly not 100k that's only cautious belt territory

[AlpsRider]

Yeah you're right, that is a bit short for a chain. I guess I am traumatized from my belt break repair bill $$$.

[///MPhatic]

Originally Posted by AlpsRider

Yeah you're right, that is a bit short for a chain. I guess I am traumatized from my belt break repair bill $$$.

I wonder if the N55/S55 is are like some other chain-driven engines where the chain stretches/slacks so much over time that it breaks the guides and has to be replaced anyway. I'd research it, but I imagine that's at a mileage my car will never see.

[AlpsRider]

Originally Posted by ///MPhatic

I wonder if the N55/S55 is are like some other chain-driven engines where the chain stretches/slacks so much over time that it breaks the guides and has to be replaced anyway. I'd research it, but I imagine that's at a mileage my car will never see.

I read a few articles that mentioned stretching chains etc. I suppose at my cars current mileage rate I won't have to worry about it ....

[doughboy]

Chain problems are usually due to tensioners or guides wearing or sticking then the chain becomes too slack and snags or slips teeth and breaks

[doughboy]

Originally Posted by AlpsRider

Yeah you're right, that is a bit short for a chain. I guess I am traumatized from my belt break repair bill $$$.

I recently had the cam belt in my 2.0d VWT6 van replaced at 100k miles rather than the 120k miles recommended....