Another Rod Bearing Story

[R60BBA]

You said your current bearings are wearing 8x less than your original bearings.

Unless you take out your replacement bearings and visually check there is no way you can make such a statement.

This is true and it is the exact issue that I have your blanket statement saying bearing wears are not much an issue for the S54. The fact of the matter is that you don't know unless you had taken out everyone's bearings and visually inspect it. I would rather err on the side cautious than wait for it to go bang.

It is not, when compared to the likes of the S65 which has an inherent design flaw due to insufficient clearance.

But if you want to believe the hype go for it.

Makes no difference to me.

[BMWZ4MC]

You said your current bearings are wearing 8x less than your original bearings.

Unless you take out your replacement bearings and visually check there is no way you can make such a statement.

This is true and it is the exact issue that I have your blanket statement saying bearing wears are not much an issue for the S54. The fact of the matter is that you don't know unless you had taken out everyone's bearings and visually inspect it. I would rather err on the side cautious than wait for it to go bang.

It is not, when compared to the likes of the S65 which has an inherent design flaw due to insufficient clearance.

But if you want to believe the hype go for it.

Makes no difference to me.

You said that you changed yours, so you must believe the hype too.

[R60BBA]

This is true and it is the exact issue that I have your blanket statement saying bearing wears are not much an issue for the S54. The fact of the matter is that you don't know unless you had taken out everyone's bearings and visually inspect it. I would rather err on the side cautious than wait for it to go bang.

It is not, when compared to the likes of the S65 which has an inherent design flaw due to insufficient clearance.

But if you want to believe the hype go for it.

Makes no difference to me.

You said that you changed yours, so you must believe the hype too.

Yeah I did, 4 years ago when I was new to M ownership.

My position has since changed and I don’t see it reverting.

[BMWZ4MC]

It is not, when compared to the likes of the S65 which has an inherent design flaw due to insufficient clearance.

But if you want to believe the hype go for it.

Makes no difference to me.

You said that you changed yours, so you must believe the hype too.

Yeah I did, 4 years ago when I was new to M ownership.

My position has since changed and I don’t see it reverting.

An easy decision when made from a position of safety. I wonder if you’d feel the same driving a >100k mile car of unknown provenance running the original bearing shells…

[GuidoK]

An easy decision when made from a position of safety. I wonder if you’d feel the same driving a >100k mile car of unknown provenance running the original bearing shells…

Indeed.
BTW the wear just continues. This is a picture of z4m bearings changed for the 2nd time from the german Z forum (lots of pictures there; obviously there are quite a few z4m's in germany ).
First time was done by Schmickler (famous german BMW z4 tuner with a z4 raceteam) at 67.000km (40k miles), and 2nd time he did himself at 127.000km (80k miles). Those germans certainly don't skimp on maintenance...

Copper just starts to shine through.
Only driven in summer, but also as summer dayly; 5 mile commute.
every 6k miles or 1 year new 10w60 castrol oil



His oil pump regulator piston was also worn, so he replaced that too:

[R60BBA]

You said that you changed yours, so you must believe the hype too.

Yeah I did, 4 years ago when I was new to M ownership.

My position has since changed and I don’t see it reverting.

An easy decision when made from a position of safety. I wonder if you’d feel the same driving a >100k mile car of unknown provenance running the original bearing shells…

Wouldn’t buy any car (let alone an M car) of unknown provenance…would you?

But I would happily buy something like a Z4M Coupe and would not be concerned about the shells as long as it had a clean service history and low owners.

I would only get them done imminently if I was seeking to track the car for peace of mind.

Life is too short to worry about things which have been blown out of proportion.

[beanie]

Whilst I’d agree that car forums often exaggerate the realities of these issues, to deny there’s a frequent problem seems like burying your head in the sand. I’d agree that the vanos issue is overstated on these but bearing wear is real and worth taking in to account imo.

Put it this way, whenever a new thread pops up about bearings, what do you expect to see inside, fresh/lightly worn shells or pictures of tired and copper coloured shells? I think I could count on one hand the amount of times bearings have come out and I’ve thought ‘they could go back in’

There’s also a lot to be said about peace of mind. Even if it is proportionally over-represented as an issue, if getting them done means you can truly relax and enjoy the car then it’s money well spent and cheap insurance in the long run.

[tomscott]

Your either one side or the other.

Its a silly argument really. There are so many factors and its down to personal preference on how you analyse risk. Being so adamant one way or the other doesn't make sense to me.

I would suggest being aware and being sensible about it is the best policy. Giving wild advice and scaremongering one way or the other doesn't help anyone, especially someone who is looking to get into a car so I would say bare it in mind.

At the end of the day finding a 1 or 2 owner car is rare now they are 15 years old. The S54 has been known for rod bearing issues since day dot, yes the variant in the Z is probably the best with the later bearings but it is a wear point.

The bottom line is that you can have a lot done at the same time to protect your investment for a relatively small amount of money.

Depends how you look at it. I would rather spend £1200 that £6k.

On the flip side.... Ive been a regular on this forum for 11 years and ive seen at most a dozen threads about cars throwing a bearing. Those cars have been used as intended, tracked and pushed hard. There were also the very unfortunate which I can think of 2, where someone has been unlucky and the engine went but the history of how the car was treated by previous owners was unknown.

Plus this is a forum you tend to find people with issues come to these places first to tell the world.

So even with the 1200 odd Z4Ms in the UK and roughly its still a tiny amount of cars (im not saying anything about concrete numbers). Plus there are a lot of European and American owners on here too so a much bigger pool.

Im not overly worried. I think a decent rule of thumb is 80-100k to have them changed. Mine is on 73 has had 2 owners, ive done 8k in 3 years so im going to aim at 80 but what ever service lands closest to that time.

These engines are still super impressive the fact that many of these engine have hit 150+ for a high performance engine is amazing yet they can do much more than that.

[flimper]

Tomscott, what other work should be done at the same time?

[PDJ]

The work that should be done at the same time is
Check replace the oil pressure relief valve plunger see picture above this if fails open will kill your engine as it dumps the oil back to sump and very little to the rest of the engine. I fitted an external one.

Oil pump drive chain and guides my guide was worn.

Then check replace everything that has to come off to get the sump pan off which is a lot if you do it at home, a garage can drop the whole front sub frame in one go but at home it is a bit at a time

Top tip if you do it your self

Strip it all down remove sump pan clean all the drips of oil off wrap sump in cling film to keep dirt out and do the bearing work a few days latter as oil dripping on your face is unpleasant

[BMWZ4MC]

Yeah I did, 4 years ago when I was new to M ownership.

My position has since changed and I don’t see it reverting.

An easy decision when made from a position of safety. I wonder if you’d feel the same driving a >100k mile car of unknown provenance running the original bearing shells…

Wouldn’t buy any car (let alone an M car) of unknown provenance…would you?…

How can a secondhand car be anything else unless it is known to you personally from the day of delivery?

[tomscott]

Tomscott, what other work should be done at the same time?

PJD knows more about this than me but other commons things to have done are engine and gearbox mounts replaced. I can feel my mounts are bad, when your on the motorway doing 60-70 hit the throttle and then take your foot off you can feel the drive train move excessively then they need doing. TBH the mounts are rubber and most will have failed by now because of age they squash and often split.




The above is an E92 but similar mount.

The mounting bolts for the cam sprockets. The original bolts are known for working themselves loose, which puts more stress on the the shank portion, and they have been known to snap straight off.

[GuidoK]

I’d agree that the vanos issue is overstated on these but bearing wear is real and worth taking in to account imo.

Both the breaking of a tab on the exhaust hub as well as those little bolts starting to shear are real problems.
I know of people who had both and are quite mellow drivers (not tracking their cars). So I don't think it's an abuse problem, it can just 'happen'.

[beanie]

Both the breaking of a tab on the exhaust hub as well as those little bolts starting to shear are real problems.
I know of people who had both and are quite mellow drivers (not tracking their cars). So I don't think it's an abuse problem, it can just 'happen'.

I know all about the issues and they, together with the engines ticks and taps, drove me crazy for a little while! I ended up getting the vanos overhauled and the pump disc replaced with the beisan part a few years back. At the time there was lots of talk about the issues and whilst I agree, it can happen, I put it somewhere between cam lobe wear and bearing wear as a potential risk.

I’d still say that, whilst potentially serious, it’s not particularly common, at least not as common as copper coloured bearings. All in my opinion, of course

[GuidoK]

it’s not particularly common, at least not as common as copper coloured bearings.

Of course it's not as common. The rodbearings wear. In every S54.
But, as far as internal engine problems go in general, still pretty common.

Cam lobe wear and cam followers wear is indeed also an issue (which is not surprising if you look at the insane cam lobe profiles the s54 has), but those should be caught when doing the periodic valve clearance adjustment.
And cam lobe wear doesn't really have the potential to seriously damage your engine, although replacing cams and followers is very expenisve, so not very nice if it's your engine that has that.
For people who are interested in replacing their oil pump regulator piston: https://burkhart-engineering.com/shop/b ... l-csl-bmw/