Got around to doing the rod bearings…

[Jimbo76]

I decided yesterday to start a job I had been putting off for a few months now…the rod bearings on my 2006, 86k mile Z4MR.

This job really is a doddle on this car, and I am doing it on the deck with axle stands…I would say, if you can handle a spanner then go for it…I was close to booking it in somewhere, but then the little ‘don’t be a last barsteward’ devil on my shoulder won the argument. This will allow me to have a few bits cleaned up or powder coated at my leisure as well while I am at it.

So…my findings. Take them as you will, the sump to me, never seemed to have been off recently, however the bearings are like new!!! Even the parent material doesn’t have that brown oil tarnished look…has the car been well looked after, or has someone beaten me to replacing these and I just don’t have the paperwork…. :roll:

I also see a paint dot on the caps, this usually, in my experience, indicates someone has marked things during reassembly. Could this be factory markings??

 

[Rockhopper]

The paint is factory. What does the shell in the bearing cap look like?

 

[Jimbo76]

The shell in the cap looks brand new….not a mark on it.

 

[PDJ]

While you have it open check the oil pump relief valve or you could be back sooner rather than latter

Wish I had photos of how mine looked when we stripped it, the pump was perfect, the relief valve not so, you either replace the pump or as I did fit an external relief valve.

 

[AndyBeech]

Doesn't look that brand new from the photo's? Still, you've got that far may as well replace them.
If you get all 6 sets laid out and take a photo will give a better indication of wear though at 80k odd miles doubt been replaced before if there's no paperwork to back it up.
Good effort doing it yourself

 

[Jimbo76]

The photos make them look worse than they are in honesty…I’ll get better ones once they’re all laid out, however, these ‘could’ easily stay in. They won’t be…but they could.

 

[Jimbo76]

While you have it open check the oil pump relief valve or you could be back sooner rather than latter

Wish I had photos of how mine looked when we stripped it, the pump was perfect, the relief valve not so, you either replace the pump or as I did fit an external relief valve.

What is the issue with the relief valve? I’m happy to have a look while I am in there.

 

[PDJ]

What is the issue with the relief valve? I’m happy to have a look while I am in there.

The issue is that it is a hardened steel spool in a softer aluminium tube and it wears a ridge in the aluminium the down side is it can stick wide open letting the oil drop back to the sump instead of lubricating the engine

When we stripped mine the original machining marks where still there in the pump but the relief valve was worn and can stick open as there was an issue with the pumps and there where non in Europe I went for an external relief valve which is adjustable, you need to re plumb the oil lines and drill and tap the sump for return, JC Racing did the machining for me not a long job I think I waited while they did it

The issue with the oil pumps that the relief valve in part of was they had been machined wrong from the factory and locked up solid straight away so all the good work you dodged was toast within seconds this has been sorted as all the pumps where returned to the manufacturer

If you fit a new pump most people put the redline engine build lube in so you get suction/priming straight away

If you contact JC Racing John will let you know how BMW motorsport rebuild the rod caps as they loctite the bolts in the caps have to be very clean no oil on the faces as they are fractured caps and any oil will hydraulically hold them apart and will fail with loos bolts when the oil leaves the gap

Hope this helps

 

[PDJ]

Oil pump

Recommended oil

Loctite

Oil pump tensioner JC Racing add an extra leak spring to this or the other but it was too late for me as I had rebuilt when they told be about it

New oil return line

New relief valve

New relief valve

 

[Mr Tidy]

FWIW I had my bearing shells replaced at 78K and although the lower ones were showing wear, the upper ones were all showing some copper.

If you haven't already done so while you've got the crossmember off check the condition of the engine mounts - mine were in a terrible state!

 

[Jimbo76]

The engine mounts are on my shopping list too. They were always gonna be done as part of the job but then when I looked at them…they were bad!! Haha.

I’m also dropping the subframe and anti roll bar off tomorrow to be blasted and powder coated. I’ll clean up around the floor area too.

 

[Jimbo76]

I found some time tonight to start getting the car back together. My socket slipped on the head of the last bearing cap bolt so had to leave that, I’ll order another one tomorrow…I could probably have gotten away with it but lost the angle I was tensioned to… Aaarrgggg!!!!

The bearings looked exceptionally good in comparison to some others I have seen!!

 

[Mr Tidy]

They do look heathy for 86K miles. Like I said 6 of mine were showing copper at 78K miles, but my car had 7 previous keepers so I figured at least one might have abused it a bit - especially as the first one seems to have been BMW UK!

To be fair they seem to be a bit of a lottery. I've seen a set worse than mine out of car on 50Kish miles, but no worse than mine out of a 100+K miler.

My thinking was to get them done soon after I got it so I would have peace of mind. All too often I've improved cars to sell them when I should have improved them when I got them so I could enjoy the benefits. :roll:

 

[Jimbo76]

Healthier than I expected, given my car has had 10 previous owners!!! Looks like I got lucky with them all taking it easy! Haha

The subframe turned out good too, after a blast and powder coating, as a freshen up aspect.

 

[Mr Tidy]

Healthier than I expected, given my car has had 10 previous owners!!! Looks like I got lucky with them all taking it easy! Haha

They must have been sympathetic owners!

I had my doubts about the BMW UK driver on mine. I mean if you got a new MC as a company car would you really get it properly up to temperature before gunning it? :lol:

 

[beanie]

Those bearings are suspiciously clean for 86k! :lol:

If they’ve been done before, then great, it’s been taken care of. If not, then it’s been taken care of! Either way it’s good news 8)

 

[Jimbo76]

Those bearings are suspiciously clean for 86k! :lol:

If they’ve been done before, then great, it’s been taken care of. If not, then it’s been taken care of! Either way it’s good news 8)

Exactly my thoughts... I am now confident that the sump hasn't been off this car, and know the bearings haven't been changed before. Had I been shown those on a bench, I would never have guessed they were original...

 

[beanie]

Incredible, if only there was a way of knowing before committing to the job.

I got mine changed at 75k ish. I’m the 3rd owner and have owned it since 32k. Always warmed up properly, over serviced with the right oil but they were distinctly average upon removal.

It’s a flipping lottery!