Rod bearings at 51k

[GT Spec]

A running in service for hydrodynamic journal bearings doesn't seem logical to me at all. I would understand after a full engine rebuild due to the new piston rings 'bedding' in to the fresh cylinder hone. Unnecessary expense if you ask me.

A running-in service for hydrodynamic journal bearings doesn't seem logical to me at all. I would understand the need for one after a full engine rebuild due to the new piston rings 'bedding' in to the fresh cylinder hone. Unnecessary expense if you ask me.

 

[lucasxdiniz]

A running in service for hydrodynamic journal bearings doesn't seem logical to me at all. I would understand after a full engine rebuild due to the new piston rings 'bedding' in to the fresh cylinder hone. Unnecessary expense if you ask me.

A running-in service for hydrodynamic journal bearings doesn't seem logical to me at all. I would understand the need for one after a full engine rebuild due to the new piston rings 'bedding' in to the fresh cylinder hone. Unnecessary expense if you ask me.

I'm a Powertrain Design engineer, so I'd like to think I have a good understanding of engines and when purely considering the function of the part, I agree with you. However, I did ask the engine builders at work if I should do an oil change because of assembly lube which can linger around and clog filters if someone abuses it (conjecture). They reckoned since it's just the rod bearings, there wouldn't be enough around to a) affect the oil (when dissolving within the oil) and b) clogging up the filter (not something they've ever seen happen in engines they've built). They suggested I could change the oil filter since it's so accessible just for peace of mind.

 

[PDJ]

They suggested I could change the oil filter since it's so accessible just for peace of mind.

I change my oil filter every 2 to 3 thousand miles between oil changes, for around £10 to £15 it is cheap insurance for the engine.

 

[PDJ]

Potentially getting at Z4MR, on 60,000 miles. Roughly what is a bmw specialist charging for a replacement?

£1200

But as you have the oil pump and relief valve (one unit) out add the cost of an oil pump as this is what kills these engine if it sticks open.

 

[Simon 3.2M]

There’s no need to run the engine in post bearing change.

 

[S54 PILOT]

129k miles bearings same condition as OP
My tech said that they will look the same right after 20k no matter the miles on the car.

 

[Mr Tidy]

They probably wouldn't look pristine after just 20K, but the third from bottom in your photo looks much worse than any of mine did after 78K miles.

But at least new ones give you some peace of mind.

 

[S54 PILOT]

No, its just light situation, 3rd one looks exactly same as on OP picture

 

[Mr Tidy]

No, its just light situation, 3rd one looks exactly same as on OP picture

Fair enough - mine looked much like that too!

 

[beanie]

Just to add to the data, I’ve just had mine done at 75k.



I’ve owned the car for 10 years and from 30k to 75k and I’ve been ultra diligent in keeping the revs and load low during warm up. Looking at the pics, I could probably have got a fair few more miles out of them but as we all know, the cost of misjudging this is high.

On another note, Redish have been fantastic-my sump had a repair done a few year back thanks to the threads being stripped by an unknown monkey. Unfortunately this has not been done perfectly so has meant a new sump has had to be ordered. Not a cheap or easily found part but communication and their willingness to help has been second to none.

If anyone for any reason someone wants a Z4m sump with a less than perfect repair then let me know. I’ll hopefully be picking the car up in the next day or two so be quick or I’ll just leave it for scrap. They’ve said it might be possible to use a timesert but because of the previous repair they weren’t convinced it would hold.

 

[joeldelman]

I'm wondering, have those posting pics of worn bearings been tracking levels of metal in their oil through Blackstone or similar? And if so, did the oil tests indicate the wear found on the parts?

I have nearly 80,000 miles on my '06 M Coupe, but Blackstone oil tests always come back extremely clear. My mechanic keeps telling me not to worry about the bearings given how I drive / maintain the car.

 

[tomscott]

Oil tests are all well and good but you can only get a base line if you have had the car a long time and a cross analysis of those tests.

For example if your only doing 3-4k a year, not pushing it all that hard doing longer journeys and youve not owned the car for long it might not show anything to worry about. The damage could have been done earlier on.

By saying dont worry, its not great advice its a serviceable item, its £1000 to sort or 5-7k for an engine rebuild. It's in his favour for it to go bang really isnt it.

One of those, its worth it for the piece of mind. Mine has done 77k and once I get to 80 il get it done. Ive been doing 1-2k year now I have a little one and two dogs so will take me another 1-2 years.

That being said on this forum specifically since 2011 I can think of half a dozen cars that an S54 has gone, 3-4 a spun bearing but a couple were driven hard or track focused and 1 overheated and warped the head.

Not all cars are on here granted so a small sample size but I think it's still overblown. Worth knowing about and being informed and making an educated judgement.

One of the key factors of there being little to no engine failures is threads like this, educating people. Plus the car is niche and you tend to find knowledgable people wanting to keep these running for a long time.

 

[Mr Tidy]

Oil tests are all well and good but you can only get a base line if you have had the car a long time and a cross analysis of those tests.

That was why I just got them replaced.

My car had 76K on it in 13 years and 7 previous keepers - oil analysis would only work over long-term ownership!

 

[swanicyouth]

Has anyone ever gone to preventively change rod bearings on an S54 w/o a little bit of copper showing?

 

[Bing]

I did mine in May at 108k miles. My car has been babied - not over 2k RPM until 75 degrees, not over 3k RPM until at just under 100 degrees oil temp. Takes about 10 miles generally. Also the oil gets changed every 7.5k miles or so. I also did regular Millers oil analyses which did not throw up any concerns. My mechanic knows all this and was convinced I did not need to do them, but it turned out I did.

However. Through and since the pandemic the car did a higher number of short journeys without getting up to full temp, which I think has contributed to wear. So I am trying to avoid that now. These photos were taken with a flash so look worse than they are… but I am glad I did them for sure.

 

[99ron]

Mine were done at around 82k. Some copper but not as bad as some with fewer miles. Probably would have gone to 100k without issue.

 

[Nick W]

Has anyone ever gone to preventively change rod bearings on an S54 w/o a little bit of copper showing?

Did mine at almost 85k, some colour change on all of the bottoms but no Copper showing or scoring. Still 100% not a waste of time. I change the oil with Helix Ultra Racing every 5k miles and drive like a Nun 'till 90 degrees but I've no clue how the past owners treated it.

 

[bigwinn]

Also 51k miles car…

 

[chris719]

How many miles has someone put on ACL bearings here? I assume a lot of you are using either OE or ACL.

 

[brownah]

Mine at 135k miles.
Sold the car after taking it to 177k.
Think the rod bearings thing is b/s on the s54 unless it's been owned by numptys