Big end bearings

[crankedup]

Reading through some posts on cutters and some people talk f having the bearings replaced as a maintenance issue!!
I know there was an issue with the very early engines but some of these owners have 2004/5 cars only with around 100k miles up.
I would expect twice that mileage before even thinking about major work such as this, given correct servicing of course. 100,000 miles is not a big mileage for modern engines after all, so it puzzling why some owners want to do this work.

[Dan_M5]

Because the V8 & V10 engines like to chew through the bearings. Mine FBMWSH spun a shell at 58k

[Mikeeb]

I had mine replaced on my M6 @ 95k. They were well past their best with one shell just showing copper. There seems to be lots of discussion about shell clearances and the oil being too thick.

My belief is that it the oil grade is relevant because it is a very highly strung engine for a mass produce road car that's fitted a normal saloon/coupe and as such gets driven like one. i.e. short school run journeys and/or pushed from cold when the oil is thick. The rev counter on mine shows that full revs are available from about 60 degree oil temperature. Far too early in my view, I restrict my to 3k until I see 75 degrees and won't use full revs until it is fully warm at 90-100 degrees.

I don't think there would be nearly so many issues if people let the cars warm up properly first.

[Max Maxasson]

More likely is that BMW made a poor choice with the ion sensing anti knock system that was poorly developed in the early S85 V10s....Later S65 V8s are far far more reliable.

[api330]

More likely cars been driven to hard before oil has warmed up

[Max Maxasson]

api330 said:

More likely cars been driven to hard before oil has warmed up

Im sure it doesn't help....however S85s are massively more unreliable than S65 engines despite both using the same bearings, clearance and oil.

[NIgt3]

They all need changed at 100,000miles, changed mines last week, cars on 78k and 2bearing shells where real bad!

[Patrick Bateman]

crankedup said:

Reading through some posts on cutters and some people talk f having the bearings replaced as a maintenance issue!!
I know there was an issue with the very early engines but some of these owners have 2004/5 cars only with around 100k miles up.
I would expect twice that mileage before even thinking about major work such as this, given correct servicing of course. 100,000 miles is not a big mileage for modern engines after all, so it puzzling why some owners want to do this work.

S85 seems to be have more issues than other M engines if you believe the internet. These are off my old M5 (e39) at 160k and it missed its running in service-

[cosworth330]

The S85 does seem to suffer more but their was a guy from Surrey called Alex that used to come on here and M5 Board who had a E39 M5 that he bought from BMW and that started knocking at 40 odd thousand miles. Luckily he got away with Phil at CPC changing the bearings and no damage done. The car did get driven though e was at the Ring several times a year.

S85 deffo suffers from this issue more though. Quite funny how the S85 won engine of the year 3 years in a row.

[crankedup]

Thanks for onteresting informative posts.

[Mikeeb]

S65's suffer from the same problem too.

[Rob_R]

Most of the people I know that have replaced them have done so @ ~70k miles. There are plenty of reputable specialists that will do the job for about £1k all in. I mean, obviously, it's a cost that we could all do without but it's not that expensive get done.

[Pdelamare]

I replaced the shells in my S65 at 118,000 miles as a precaution. I'd read myself into a state of bearing-knock paranoia.

Some say they don't look too bad, some say they were totally worn. I have no idea, but they don't look as bad as some I've seen from S65s with half or quarter of the miles. I hope the new ones last another 118k.

[Cheburator mk2]

Max Maxasson said:

More likely is that BMW made a poor choice with the ion sensing anti knock system that was poorly developed in the early S85 V10s....Later S65 V8s are far far more reliable.

That is so incorrect, that there is no point even discussing it...

[SebringMan]

I would take a bit of stuff on M3cutters with a pinch of salt. If you believe a few of the posts:

-All boot floors will crack
-The HG is a ticking timebomb
-The SMG is around £3k to fix and will die within 50k.
-Big ends are guaranteed to go.

In short, while the above issues do exist IMO they are exaggerated in a few cases.

There is another thing to remember. Alot of people will rev them hard right from the off and skip parts of the maintenance. After all, they are now a car available for Mondeo money. A car maintained on the cheap can bring about issues.

That said, I may end up getting my boot floor reinforced this summer :/.

[crankedup]

^^^^^^^^^
As a newbi to BMW, well I had a 523i about 15 years ago but didn't keep it long, swopped it in for a TVR. Reading some cutters posts made me start thinking that the E6 M3 is a bag of nails poorly designed and engineered!! Nothing could be further from the truth, the key, as your mention, is correct servicing, as with any high performance vehicle. My recent E46 M3 purchase is a fantastic car and so happy to be able to enjoy it. It has cost me money for a few minor issues to be dealt with that frankly any car could have developed, but I can live with that. Its mine for the next three years or so and then its going into our lads garage, well thats the plan

[carbonblack]

SebringMan said:

I would take a bit of stuff on M3cutters with a pinch of salt. If you believe a few of the posts:

-All boot floors will crack
-The HG is a ticking timebomb
-The SMG is around £3k to fix and will die within 50k.
-Big ends are guaranteed to go.

The boot floor may well be exaggerated on M3Cutters but a lot of the general public and (small independent) dealers have no idea that this issue even exists. I'd actually more cars than not will suffer this fate eventually even if it's a hairline crack.

Big end issue is probably not as recognised as it should be on the S54. Mine were done around 130k and were showing serious signs of wear (nearly to the point of failure) on a 1 previous owner car who always warmed it up and changed the oil every 5-6k a tradition which I continued in my ownership.

[crankedup]

carbonblack said:

SebringMan said:

I would take a bit of stuff on M3cutters with a pinch of salt. If you believe a few of the posts:

-All boot floors will crack
-The HG is a ticking timebomb
-The SMG is around £3k to fix and will die within 50k.
-Big ends are guaranteed to go.

The boot floor may well be exaggerated on M3Cutters but a lot of the general public and (small independent) dealers have no idea that this issue even exists. I'd actually more cars than not will suffer this fate eventually even if it's a hairline crack.

Big end issue is probably not as recognised as it should be on the S54. Mine were done around 130k and were showing serious signs of wear (nearly to the point of failure) on a 1 previous owner car who always warmed it up and changed the oil every 5-6k a tradition which I continued in my ownership.

My car has 103,500 miles up, in my old cars from the past big ends meant a not so nice knocking noise. From what I gather modern engines need an oil anylisis that detects bearing wear? I am amazed that bearings are knackered within such a short life. Cost of peeformance I suppose.

[Steve Barrett]

Mines going in shortly for King Racing bearings, ARPs and Vac Motorsport oil pump drive and pulley. Purely as preventative maintenance as the cars done 119k and for my piece of mind the £1000 is worth it.


Steve

[crankedup]

Steve Barrett said:

Mines going in shortly for King Racing bearings, ARPs and Vac Motorsport oil pump drive and pulley. Purely as preventative maintenance as the cars done 119k and for my piece of mind the £1000 is worth it.


Steve

1k seems to be good value. I have to ask, purely as I am trying to learn and understand the e46 M engine, Is your engine showing any signs of wear? Do the bearings just suddenly go pop, this all seems just so alien to what I have known over the past 50 years of motorbikes and car engines.