Rod bearing failure - what to do?

[exdos]

In view of the fact that the bearings shells of most S54 engines, of which there are 12 parts per engine, will show signs of pitting/scoring after the engine has done significant mileage, the fact remains that only a very small number of bearings actually fail catastrophically (i.e. only 2 bearing shells per failed engine), would suggest to me, at least, that this is not, itself, the fundamental cause of bearing shell failure/destruction.

OTOH, how would the failure of the connecting rod bolts, by stretching beyond tolerance, manifest itself other than by permitting the crankshaft to hammer the bearing shells into much thinner pieces?

IMO, if you're going to inspect the bearing shells, then you should also commit to changing them AND the con-rod bolts for new upgraded parts.

A bad gear shift, say, into 2nd gear instead of 4th, would also be an occasion which could cause catastrophic bearing shell failure.

 

[ph001]

Ive been here for 8 years and have seen there has been around 6-7 instances, its a forum people come here for these types of problems so its not common. On the other hand these cars are hitting bigger milage now.

Quite true, also a good indicator is how many instances there are of it over on M3Cutters. There are 1000+ S54 M owners on there and reports of failures are under 1%.

 

[R60BBA]

Its not the smallest job so makes sence to have other jobs done at the same time.

Mounts, bolts etc

I wouldn't be panicking this happens on a rare basis and there are so many different factors that its impossible to give an indication on what each cars wear it like unless you have owned the car since new.

Ive been here for 8 years and have seen there has been around 6-7 instances, its a forum people come here for these types of problems so its not common. On the other hand these cars are hitting bigger milage now.

Just add it to the next round of maintenance.

It’s not rare, in fact it’s becoming more common.

Unless you have owned the car from new, it’s impossible to know how it has been looked after by former keepers.

£1,000 to get this sorted isn’t a big deal and should be done on any car over 70,000 miles. If you cannot afford this then you should not be driving one of these.

 

[tomscott]

It depends who you talk to as I said forums are places people bring these issues to light and obviously the Z4 is lower volume than the M3 but its certainly not common.

Same with Porsche I always thought it was internet scaremongering until I bought a car and 2 weeks later had a 12k bill for a rebuild...

That being said you still have to be very unlucky.

 

[R60BBA]

It depends who you talk to as I said forums are places people bring these issues to light and obviously the Z4 is lower volume than the M3 but its certainly not common.

Same with Porsche I always thought it was internet scaremongering until I bought a car and 2 weeks later had a 12k bill for a rebuild...

That being said you still have to be very unlucky.

There’s a lot less Z4Ms than M3s and I’d even stipulate that as a 2 seater, they are more likely to have less miles on em than M3’s.

They are also up to 2 years younger than the last E46 M3s and 7 years younger than the first MK20s.

However they have the same engine and so the same thing can occur as per the unfortunate 2 examples in this very thread.

In my post I wasn’t just referring to examples on forums where people have posted about their rod bearing failures, but I was also taking into account discussions which I have had with various M specialist garages on this, who have all confirmed that it is becoming more common in recent years.

You also cannot ignore that MK20 M3s had this job done under recall, which affected thousands of cars...further reinforcing it has been a problem area from day 1.

I did mine for peace of mind. The shells came out clean and I could’ve waited another 30,000 miles or so however I could’ve been ‘unlucky’ as you put it and spun a bearing in 5,000 miles.

Either way I no longer have that worry as the job is done. Now my concern is the flippin’ boot floor. :roll:

 

[Bing]

I better put mine up for sale because apparently I shouldn't be driving it, given it's on 83k, has not had the shells replaced and I don't have a spare grand right now ... I must also remember to knock £1k off the asking price because the shells have not been done, and I am sure that will become a common bargaining point in the near future

In all seriousness, based on everything everyone is saying, if you can afford to have this done by 70k (an arbitrary number by the way, with no empirical evidence presented or probably even possible to present) then you probably should. If you can't then budget to do it at about 80-100k and in the meantime pay attention to the car - regular interim oil & filter changes, on-time servicing, visual inspection, regular oil analysis, and treat the car with mechanical sympathy.

EDIT - sorry, I probably should have put a smiley face in here somewhere... Now corrected for tongue-in-cheek :lol:

 

[mmm-five]

I think they should be done every Insp.II

That’s about 50-55,000 miles for daily drivers, or 40,000 miles for garage queens/weekend cars...and work out about £500 extra per year for daily drivers or £100/year for the rest.

Or about £50/year in my case (if you don’t include the cost of my replacement engine) :?


Whichever way you look at it, it’ll cost less than VED

 

[Bing]

Ha, that's not necessarily a shit idea. Funnily enough 100k will be around my second Insp 2. And as I have already said, that's what I'm budgeting towards.

 

[R60BBA]

I think they should be done every Insp.II

That’s about 50-55,000 miles for daily drivers, or 40,000 miles for garage queens/weekend cars...and work out about £500 extra per year for daily drivers or £100/year for the rest.

Or about £50/year in my case (if you don’t include the cost of my replacement engine) :?


Whichever way you look at it, it’ll cost less than VED

Well put 8)

 

[mmm-five]

Once I’ve put my ‘new’ engine in (47k on it), the only original parts will be cats, bonnet, roof & gearbox.

If I’d done the rod bearings earlier, I would have still had a 140,000 mile old engine, but with new bearings...so you just know I’d be needing vanos, cams, rods, etc. shortly too.

This way I’ve now got a low mileage car again

 

[TomK]

Once I’ve put my ‘new’ engine in (47k on it),

So are you doing the rod bearings on the 'new' engine, given I guess you have no idea on the past 47k usage?
Nothing to say you won't be in the same boat again at potentially some point soon if you don't imo. Whilst it's out of the car why not refresh it?

 

[mmm-five]

So are you doing the rod bearings on the 'new' engine, given I guess you have no idea on the past 47k usage?
Nothing to say you won't be in the same boat again at potentially some point soon if you don't imo. Whilst it's out of the car why not refresh it?

Bearings and Insp.II planned for the new engine before it goes in. Seemed no point in checking them for wear and not replacing them whilst it's all open :headbang:

Then keep some of the spare parts, for spares.

 

[TomK]

Good stuff For sure that's the pragmatic approach. At least you'll have one less thing to worry about :lol:

 

[mmm-five]

Good stuff For sure that's the pragmatic approach. At least you'll have one less thing to worry about

I’ve had Ms for a while, so sleep like a baby...unless it’s in a dealer for a service :roll:

Plus the amount I’ve saved in fuel & maintenance since I got the Alfa 147 means it’s not really cost me anything - I’m sure this is the same sort of thinking the UK Government uses too.

 

[GuidoK]

Same with Porsche I always thought it was internet scaremongering until I bought a car and 2 weeks later had a 12k bill for a rebuild...

Whether something is scaremongering or not is very easy to investigate.

If there are lots of different pictures on the internet of that problem (like there are on these rodbearing shells), then its a problem.
I mean, cross reference that with number pictures of bearingshells on the m54, an engine that is sold probably in tenfold to the s54.
You might find 1 or 2 if you look very hard :lol:
It's that difference with similar engines that says it all.

BTW doing rodbearings every 50k miles is only a 2p/mile extra maintenance cost. I think thats very reasonable for driving a sportscar that revs til 8krpm.
I mean if you'd go on a nice holiday trip, say from birmingham to florence italy, and do some driving there, that would only be £60 extra on car maintenance. Thats nothing imho.

 

[BMWZ4MC]

I should think Florence would prove to be a disappointment for someone lucky enough to live in as magnificent and wonderous a place as Birmingham :lol:
I try to be pragmatic about such things - better a definite £1k cost every 50k miles than the potential for a £5-8k cost, huge inconvenience and a sense that the car has somehow betrayed you (a crazy emotional response I know!).

 

[GuidoK]

I try to be pragmatic about such things - better a definite £1k cost every 50k miles than the potential for a £5-8k cost, huge inconvenience and a sense that the car has somehow betrayed you (a crazy emotional response I know!).

Or having your car blown up in florence, and not have sufficient insurance to get alternative transport covered or the repatriation of your car.
Having had that twice (dont ask...) but with the right coverage, I can say how importatnt that is as I earned back my travelinsurance premium for the next 350 years or so :rofl:

 

[Tusk]

Is there a cost synergy to doing this at the same time as an inspection 2? Thought the quote of £1400 early in this thread for both seemed pretty good.

 

[exdos]

I should think Florence would prove to be a disappointment for someone lucky enough to live in as magnificent and wonderous a place as Birmingham :lol:

You're getting mixed up with your Italian cities: Birmingham, with all its canals, is considered to be the Venice of the Midlands. :rofl:

 

[BMWZ4MC]

I should think Florence would prove to be a disappointment for someone lucky enough to live in as magnificent and wonderous a place as Birmingham :lol:

You're getting mixed up with your Italian cities: Birmingham, with all its canals, is considered to be the Venice of the Midlands. :rofl:

Except Venice is sinking...then again so is Birmingham!