Z4M Crank Rod Bearing Shells

[PDJ]

I know but I clicked on the text expanded it then the little bubble to put in a quote popped up clicked on that and added a photo

I am not clever enough with a computer to be miss quoting and changing peoples names etc.

So don’t know how it has been posted like that

[BMWZ4MC]

The advice often posted here as long ago as c 2011 used to be that changing them before 100k miles is sensible preventative maintenance. Typically the sources for that advice were cited variously as ///M specialists and the expert opinion of members with engineering experience.

As a background for my car, it was briefly a daily driver in 2009-10 but has spent most of the the 11 years and 60k miles in my ownership as a track car and a car for hooning. Almost all of the track miles and a great many of the road miles have been covered on soft compound semi-slick tyres which allow higher g forces during cornering with the potential for oil starvation. I doubt there has been a single journey in my hands during which it hasn’t seen 8,000 rpm multiple times. However, it has been serviced markedly more frequently than most and never driven hard until thoroughly warm. I am the second owner.

Due to the nature of my usage of the car, I had the bearing shells changed at 50k miles. They were described as fine and didn’t look excessively worn to my eyes, but I have no photographs. Will I change them again before 100k miles? Absolutely!

Ed Doe and mmm-five, I’m sorry to hear of your respective engine woes and the impending bills. Especially since they are examples of a decreasing number of Z4Ms that are used to their full potential on a regular basis.

[mmm-five]

I know but I clicked on the text expanded it then the little bubble to put in a quote popped up clicked on that and added a photo

I am not clever enough with a computer to be miss quoting and changing peoples names etc.

So don’t know how it has been posted like that

Just edit your post to change the

Code: Select all

[quote=mr wilks]

to the userid of the original poster

Code: Select all

[quote=BTZ461]

[mmm-five]

Ed Doe and mmm-five, I’m sorry to hear of your respective engine woes and the impending bills. Especially since they are examples of a decreasing number of Z4Ms that are used to their full potential on a regular basis.

It was one of those things on my wish-list for the winter, and just unfortunately happened on the last Ring trip of the year before winter.

Did a good weekend of laps, gave it to my mate to do a couple, and then went to fill up to do more laps. Filled up, started the car and it sounded/felt a bit lumpy (like the lumpy idle on an s38b38 in an e34 M5 if you've ever had one) - but the S54 is usually smooth. Revved it a little...slowly...to about 1500rpm and we then shut if off. It was then started again at a local specialist in Nurburg when the recovery driver dropped it off. Took the oil filter out and it was covered in metal - both inside and out. Took the cam cover off and we could see some evidence there too (not lots, but you could see the twinkle as torch lights hit something). There was no way it was being driven home, so got it repatriated.

Limited strip down came up with 2 options:

1. Strip down, rebuild, upgrade
2. Replace

Problem with the first option is that it could be an almost limitless cost, depending on how far the contamination had gone, and what else you replace/upgrade whilst the engine is out (e.g. valves, pistons/rings, vanos, oil cooler, cams, top & bottom shells, crank, etc.).

Quick internet searches for s54b32 engines on the internet showed we could get a engine for anywhere from £2600 fitted from a dodgy engine refurb place in Heathrow or Essex - or £8k for a random 60,000 mile one. The average was about £4500 - but from private sellers, with no warranty, who had no proof the engine was even running.

We decided to wait a while as I was going skiing for 3 weeks after Christmas and we'd do something in February.

Whilst I was on holiday, on one of my rest days, I got a ping from an ebay alert I'd set up. It was from a salvage company who'd just taken in a rear-damaged 2017 Z4M - and was I interested in a 40,000 mile engine. After a bit of negotiation, we got the engine and a load of ancillaries (alternator, oil cooler, AC pump, intake manifold, etc.) for the same price as others were asking for the bare engine...with a 3 month warranty from date of delivery.

Goes to show how a £1000 preventative bill becomes £6000 - but it's the delay in getting the swap done that's more annoying.

• Finding a good, low mileage 2nd hand engine took a couple of months - and I ended up with a Z4M S54 rather than a e46 one (no major differences, just don't need to mess around with different engine looms)
• Garage/friend doing the swap got seriously ill, so I said to put mine on the back burner and do the simple/easy/little jobs on other's cars that he felt up to
• His house/workshops got flooded (with added crap from neighbour's farm)
• Stress of all this caused a relapse
• Covid (he's in the shielded group)

My worry now is that everything else on the car will have rotted/rusted in the time it's been sat doing nothing - and there'll be another big bill to fix all these little things

I really should get the car/engine transported to a more local specialist, but as it's a friend doing it I don't want to take away potential earnings when the income is needed more than ever due to being out of action for so long.

I should have just stripped it for parts when I had the chance - as things have just gone downhill ever since I rejected the insurance write-off opportunity in 2015.

Of course, there's nothing to say that someone else's will last to 200k miles, or that they'll fail at 20k - it's a bit of an unknown - just like some have had vanos failures early on, and others have never had an issue. Others have had roof motor problems - I've never had that

I'd probably now add the rod bearings to an Inspection II cost/schedule - so every 2 years if you use the car a lot, or every 5-10 years if you don't. Doesn't seem much cash when you spread it across a few years.

[mr wilks]

Mmmmr-five you have had a rough ride with that car

[mmm-five]

Mmmmr-five you have had a rough ride with that car

It's why I keep turning up to meets in random diesels. The M-boys probably thought I was going to overtake them with my 115bhp.

I think my decision to change it from daily driver doing 25-30k miles a year to a weekend/trackday car didn't go down well with it, so it started throwing strops - must have been jealous of the attention the sub-£1k Alfa diesels were getting - not realising that I was trying to turn it into my 'special' car rather than just 'normal' car.

[Argenta]

3rd answer option tells me theres some mechanical knowledge missing. What do you mean ”1 or 2 failed”?
I changed mine as precaution, all bearings were very worn but the crank was still good.
The bearings dont ”fail” but wear gradually.

[Smartbear]

3rd answer option tells me theres some mechanical knowledge missing... What do you mean ”1 or 2 failed”?
I changed mine as precaution, all bearings were very worn but the crank was still good.
The bearings does not ”fail” but wear gradually.

They can also spin i believe, I’d call that a failed bearing
Rob

[GuidoK]

3rd answer option tells me theres some mechanical knowledge missing... What do you mean ”1 or 2 failed”?
I changed mine as precaution, all bearings were very worn but the crank was still good.
The bearings does not ”fail” but wear gradually.

[/quote]

They can also spin i believe, I’d call that a failed bearing
Rob

You're lucky when you get them in their 'gradually fail' stadium (its about a 1000gbp pre emptive maintenance, best done at 55k, so less than 2ct/mile)
You're less lucky if they spin: either new crank, or regrinded crank with undersize bearings and a conrod
You're f***ed if the bearing spins, seizes and the conrod breaks, putting a nice new hole in your block.

Just change them at ~55k miles. If you can't pay for the ~1,8ct/mile pre emptive maintenance, don't drive an engine that revs to 8k+....
When doing the rodbearings, also replace/inspect the oil pump pressure plunger, its a known wear item.

[SiJar]

Well the Honda S2000 never suffered engine issues and that use to rev to almost 9k. I believe Honda used to say and advertise the fact that they never had a single engine fail below 100k miles. Not too sure how accurate that was but it was a terrific engine in its day for a 2 litre non turbo.

[XMetal]

Well the Honda S2000 never suffered engine issues and that use to rev to almost 9k. I believe Honda used to say and advertise the fact that they never had a single engine fail below 100k miles. Not too sure how accurate that was but it was a terrific engine in its day for a 2 litre non turbo.

Google search tells me otherwise.

[RedUn]

Well the Honda S2000 never suffered engine issues and that use to rev to almost 9k. I believe Honda used to say and advertise the fact that they never had a single engine fail below 100k miles. Not too sure how accurate that was but it was a terrific engine in its day for a 2 litre non turbo.

Google search tells me otherwise.

The 100k thing is a vtec failure, lots of engines gone pop before then, mostly due to people skimping on maintenance and fuel choice

[BMWZ4MC]

3rd answer option tells me theres some mechanical knowledge missing... What do you mean ”1 or 2 failed”?
I changed mine as precaution, all bearings were very worn but the crank was still good.
The bearings does not ”fail” but wear gradually.

They can also spin i believe, I’d call that a failed bearing
Rob

You're lucky when you get them in their 'gradually fail' stadium (its about a 1000gbp pre emptive maintenance, best done at 55k, so less than 2ct/mile)
You're less lucky if they spin: either new crank, or regrinded crank with undersize bearings and a conrod
You're f***ed if the bearing spins, seizes and the conrod breaks, putting a nice new hole in your block.

Just change them at ~55k miles. If you can't pay for the ~1,8ct/mile pre emptive maintenance, don't drive an engine that revs to 8k+....
When doing the rodbearings, also replace/inspect the oil pump pressure plunger, its a known wear item.

Useful information about checking the oil pump too

[BMWZ4MC]

Ed Doe and mmm-five, I’m sorry to hear of your respective engine woes and the impending bills. Especially since they are examples of a decreasing number of Z4Ms that are used to their full potential on a regular basis.

It was one of those things on my wish-list for the winter, and just unfortunately happened on the last Ring trip of the year before winter.

Did a good weekend of laps, gave it to my mate to do a couple, and then went to fill up to do more laps. Filled up, started the car and it sounded/felt a bit lumpy (like the lumpy idle on an s38b38 in an e34 M5 if you've ever had one) - but the S54 is usually smooth. Revved it a little...slowly...to about 1500rpm and we then shut if off. It was then started again at a local specialist in Nurburg when the recovery driver dropped it off. Took the oil filter out and it was covered in metal - both inside and out. Took the cam cover off and we could see some evidence there too (not lots, but you could see the twinkle as torch lights hit something). There was no way it was being driven home, so got it repatriated.

Limited strip down came up with 2 options:

1. Strip down, rebuild, upgrade
2. Replace

Problem with the first option is that it could be an almost limitless cost, depending on how far the contamination had gone, and what else you replace/upgrade whilst the engine is out (e.g. valves, pistons/rings, vanos, oil cooler, cams, top & bottom shells, crank, etc.).

Quick internet searches for s54b32 engines on the internet showed we could get a engine for anywhere from £2600 fitted from a dodgy engine refurb place in Heathrow or Essex - or £8k for a random 60,000 mile one. The average was about £4500 - but from private sellers, with no warranty, who had no proof the engine was even running.

We decided to wait a while as I was going skiing for 3 weeks after Christmas and we'd do something in February.

Whilst I was on holiday, on one of my rest days, I got a ping from an ebay alert I'd set up. It was from a salvage company who'd just taken in a rear-damaged 2017 Z4M - and was I interested in a 40,000 mile engine. After a bit of negotiation, we got the engine and a load of ancillaries (alternator, oil cooler, AC pump, intake manifold, etc.) for the same price as others were asking for the bare engine...with a 3 month warranty from date of delivery.

Goes to show how a £1000 preventative bill becomes £6000 - but it's the delay in getting the swap done that's more annoying.

• Finding a good, low mileage 2nd hand engine took a couple of months - and I ended up with a Z4M S54 rather than a e46 one (no major differences, just don't need to mess around with different engine looms)
• Garage/friend doing the swap got seriously ill, so I said to put mine on the back burner and do the simple/easy/little jobs on other's cars that he felt up to
• His house/workshops got flooded (with added crap from neighbour's farm)
• Stress of all this caused a relapse
• Covid (he's in the shielded group)

My worry now is that everything else on the car will have rotted/rusted in the time it's been sat doing nothing - and there'll be another big bill to fix all these little things

I really should get the car/engine transported to a more local specialist, but as it's a friend doing it I don't want to take away potential earnings when the income is needed more than ever due to being out of action for so long.

I should have just stripped it for parts when I had the chance - as things have just gone downhill ever since I rejected the insurance write-off opportunity in 2015.

Of course, there's nothing to say that someone else's will last to 200k miles, or that they'll fail at 20k - it's a bit of an unknown - just like some have had vanos failures early on, and others have never had an issue. Others have had roof motor problems - I've never had that

I'd probably now add the rod bearings to an Inspection II cost/schedule - so every 2 years if you use the car a lot, or every 5-10 years if you don't. Doesn't seem much cash when you spread it across a few years.

Hope your friend recovers soon and continues to keep well avoiding covid.
It’s good you got the correct engine and one of low mileage. Will you change the shells before it’s fitted?
I doubt there are many other Zeds that have had three engines (except a few race cars)!

[mmm-five]

Hope your friend recovers soon and continues to keep well avoiding covid.
It’s good you got the correct engine and one of low mileage. Will you change the shells before it’s fitted?
I doubt there are many other Zeds that have had three engines (except a few race cars)!

Yes. It's going to have an I2 and shells done before it goes in.

Did consider cams, carbon CSL-style airbox & tune - but the cost was getting ridiculous, so will keep it standard for now.

Hopefully this 3rd engine will last as long the 2nd (140k), rather than the 1st (23k)