Z4M S54: Rod Bearings Replaced

[ctdriver86]

Hello Randy, thanks for the help. I also have an e46 m3 and had some parts laying around so I used ACL WPC treated rod bearings with OEM rod bolts. The bearings I pulled from the 94k mile z4m were definitely due. Copper was showing on all top bearings. I'm guessing maybe it has to do with how often the car was driven?

I pulled bearings from my m3 at 155k miles (no history) and the bearings were in much better condition. The car was neglected so I doubt the bearings were done. I also pulled bearings from a 72k mile 2002 early rod bolt m3. The car was driven often until around 72k miles and was in a rear end collision where it sat for over 10 years. The bearings were in good shape actually. It's just my speculation since I don't seem to see a consistent pattern of wear with the s54 bearings other than the top bearing wear maybe on ignition stroke?

[Emmrbee]

Replaced with VAC high performance rod bearings and ARP M10bolts
Engine mounts changed at the same time. Engine had 76,411 kilometres on the clock.

[grannyknot]

Just got to the rod bearings and main bearings, pretty sure the rod bearings are the second set, the mains I think are original, car has 91,000 mi.
Would like to hear anyones read on the mains, the journals on the crank are very nice.
First pic is the uppers, can anyone tell me what those blobs are on the lower 6,5,4 bearings?
Last pic are the mains.

[maupineda]

Do you know the mileage on the second set? They were not due for a change and IMO could have gone for another 30-40k kms.

Mains are barley worn, but without measuring them, is tough to say how much. They did not need changing though. These engines do not consume main bearings as is the caee with the rods’.

[ctdriver86]

Originally Posted by grannyknot

Just got to the rod bearings and main bearings, pretty sure the rod bearings are the second set, the mains I think are original, car has 91,000 mi.
Would like to hear anyones read on the mains, the journals on the crank are very nice.
First pic is the uppers, can anyone tell me what those blobs are on the lower 6,5,4 bearings?
Last pic are the mains.

You changed the main bearings without removing the crank?

[grannyknot]

Originally Posted by maupineda

Do you know the mileage on the second set? They were not due for a change and IMO could have gone for another 30-40k kms.

Mains are barley worn, but without measuring them, is tough to say how much. They did not need changing though. These engines do not consume main bearings as is the caee with the rods’.

I don't know the mileage when they were changed, was given very little history of the car. It is the weird spots on the mains that have me puzzled.

Originally Posted by ctdriver86

You changed the main bearings without removing the crank?

No, I just opened the engine and this is what I found but I will be replacing all with fresh bearings.

[G80indy]

Speaking of rod bearings just bought an RSX for soon to be driving child.
174k miles = No worries:
- K20 engine
- full maintenance records - oil changes from day one, average every 3k miles