Bearing Failure (pics)..... Opinions wanted.

QikNish

Well-known member
So, short & long of it... a customers 2008 BMW M6 Coupe comes to our workshop with engine noises. My brother diagnosis it without stripping as bearing failure (he should know since his 85,000km M3 DCT had ran a bearing a week before during a BMW organised MDrive Event - Motorplan installing new engine this week).

ANYHOOOOW... back to the M6. Under 62,000km on the clock. Out of Motorplan due to time but has full BMW history. Car looks immaculate. See pics of strip down below. I'm more disappointed than shocked at M build quality. My E36 M3 seems built to last - not the newer cars.

My big question is - has anyone got experience with VAC coated bearings? I want to replace the bearings on my E92 M3 6MT as preventative maintenance. Should I just go with stock? My brother has a valid concern regarding clearances on "coated" bearings. By the way - i use Mobil 1 and change oil every 6 months / 10,000km (sometimes even less). No issues with my car & i clock mileage like a trucker.

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e23

Member
:cry::blueCry:

From your knowledge did the ///M only use TWS or similar?

With that mileage I guess it was on plan & would have only been to the stealers for lube services etc. The reason I mention this is that peeps drop their cars off at the stealers & assume all & sundry is well.:RedNo:

I won't go on....
 

QikNish

Well-known member
e23 said:
:cry::blueCry:

From your knowledge did the ///M only use TWS or similar?

With that mileage I guess it was on plan & would have only been to the stealers for lube services etc. The reason I mention this is that peeps drop their cars off at the stealers & assume all & sundry is well.:RedNo:

I won't go on....

Thats the part I don't like - a 60,000km M6 would have only had 2 oil changes. TWS only. Yet probably driven the way it was supposed to be.... that will ruin any engine.
 

Ratslaaf

///Member
I've been spending a lot of time over at m3post reading the bearing threads. The latest VAC bearings are now 0.005" thinner than stock to allow for the Calico coating to be applied, the result, with coating, is now the same as the stock bearings.

I'm going to be doing it on my car, but using the stock rod bolts. I'm sitting on 100k so it really is time.
 

spawn616

New member
from my limited knowledge

i would use vac or acl(many a honda and bike builds done by me)

but these engines are highly strung and dealerships(bmw dealers) go according to a book, and its pretty apparent that the oil changes are not soon enough because bmw in sa atleast believe in lifetime oil:hammerhead:
 

Crash_Nemesis

///Member
The vac bearings were installed when the engine was 100 000km old.

The engine was on 142 000km when we stripped her last year. So the bearings were on 42 000km when we checked. The car is now on 152 000km.

They should fit with OEM stuff. Remember, my engine has HPF rods and CP pistons and overbored with ARP studs and bolts. So my engine is by no means OEM, but VAC do advertise the coated bearings as OEM friendly. Speak with a rep from VAC to get more info, but from my understand they are a straight fit.
 

Peter@AEW

BMWFanatics Advertiser
Official Advertiser
From my experience I would propose that the crank may well need straightening.

In addition I would polish the big end journals 0.005 larger than stock to aid in oil drainage.

Also the conrods may need to be polished on the sides to give better clearance, check the big end of the rods for blueing as they are known to come together due to tight side clearances.

It is a known issue with the M engines that the clearances are too tight for the thickness of oil used.


Can you post a pic of the rods (sides facing each other and the sides facing the crank)
 

Xack

Active member
Oh boy, I need my bearings done ASAP. ..having way too much fun in my car sitting on 160k
 

ptmatjila

New member
Rod bearing failure is a serious problem on any m car with a mileage > 100k...talk to a bmw specialist, use high performance engine oil (the ones costing around R2000) or be prepared to go on anti depressants after realising that you have to fork out over 100k for an M car knocked up engine. I know because I am a recent casualty.
 

Crash_Nemesis

///Member
ptmatjila said:
Rod bearing failure is a serious problem on any m car with a mileage > 100k...talk to a bmw specialist, use high performance engine oil (the ones costing around R2000) or be prepared to go on anti depressants after realising that you have to fork out over 100k for an M car knocked up engine. I know because I am a recent casualty.

Been there too man... not fun.
 

Pho3niX90

///Member
What exactly was the engine sound the car had that called for concern? Just go to show bearings weren't fixed on m cars after 2007, eventhough everyone likes to believe so.
 

Fordkoppie

///Member
QikNish said:
Thats the part I don't like - a 60,000km M6 would have only had 2 oil changes. TWS only. Yet probably driven the way it was supposed to be.... that will ruin any engine.

The scary part is that when looking at the lack of any varnish, this engine had more frequent oil changes than the dealer specified 25000km.

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It would have been much dirtier if it didnt have additional oil services.
And yet, after all that extra expenses and trouble, it still didn't save the engine.:cry:
 

pimpassdaddy

Well-known member
The scary part about these engines is the randomness of failure. It would be more comforting if there was a genuine concern from, say, 90 000km +... But after reading all the threads, I'm quite sure I have LOL, there's just many that go around 50 000 - 60 000km, and then those that are at 120 000km+ and nothing.

Preventative change is the only way to rest easy... Lord knows I don't. :hammerhead:
 

Xack

Active member
Stop with the scary stories about running bearings already..... they way things are going,iam gonna start a "post running bearing support group" :biglol::chef::chef:
 

anton-sa

Active member
and here i drive a oldskool 2000 530d with m57d30 and at 297000km the motor only just feels run in... haha ;) eish.. there goes the idea of owning a newer //m.....
 
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