2006 ZCP Rod Bearings @ 85K

[~CSL~]

Just a data point for everything we already know, and for anyone "one the fence" about doing the bearings. When I picked mine up a few weeks ago, I took it directly to a shop to have the VANOS and rod bearing done, glad I did. Really just a reference info...

Cheers,

[simon_c]

Just curious, did you run an oil analysis before you replaced them? I’m at 88K miles and haven’t replaced mine but have 10 years worth excellent oil analysis reports so have held off on doing them. It’s the only big 3 I haven’t done yet

[~CSL~]

Just curious, did you run an oil analysis before you replaced them? I’m at 88K miles and haven’t replaced mine but have 10 years worth excellent oil analysis reports so have held off on doing them. It’s the only big 3 I haven’t done yet

I picked the car up about three weeks ago - I knew none of the big three were done. The previous owner told me everything was good and that the Blackstone reports were clean, offered to send them to me, but I declined. I was having the bearings done either way - so I never asked for them. I didn't really even drive the car once I got it - the first real miles on it were freeway speeds heading to the shop.

Take that for what it is worth - but if I were you, I'd get them done.

[sasha]

Here is a thread that the oil analysis (if so inclined to ask for it now) and that picture would be good to document in.

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/801-rod-bearing-showcase-thread/page3

[bigjae46]

I picked the car up about three weeks ago - I knew none of the big three were done.

That is the way to buy an M3. I don't trust the average fast and furious ex-owner putting king bearings in the car. Rather do it myself to know it was done right with quality parts. Given the rising prices of S54s, I'd always immediately do rod bearings when buying an E46...and even an E9X.

[chris719]

That is the way to buy an M3. I don't trust the average fast and furious ex-owner putting king bearings in the car. Rather do it myself to know it was done right with quality parts. Given the rising prices of S54s, I'd always immediately do rod bearings when buying an E46...and even an E9X.

Agreed. I think if done properly even King bearings would be ok though. I personally went with ACL H and HX and sent them myself to Calico to get coated to recover some of the clearance, I liked how the VAC Calico coated bearings seemed to look when coming out of engines, but VAC wouldn't tell me what their target clearance is. I plastigauged all 6 to 0.002" (0.0051 mm) and used the entire HX set and did not mix with the H. Hot idle and load oil pressure seems roughly the same as before.

[sapote]

Perfect timing. Seems car wasn't pushed hard by previous owners.

[chris719]

Just curious, did you run an oil analysis before you replaced them? I’m at 88K miles and haven’t replaced mine but have 10 years worth excellent oil analysis reports so have held off on doing them. It’s the only big 3 I haven’t done yet

The problem with oil analysis is that it doesn't really catch everything. Certain particle sizes get missed by the method the labs normally use. A long history is a good indicator but hard to fully trust. I would say that bad UOAs mean you have an issue but good UOAs are not necessarily conclusive. There were a couple examples on m3post of S65 engines having many good UOA in a row but then still spun a bearing or looked really bad on teardown.

[~CSL~]

That is the way to buy an M3. I don't trust the average fast and furious ex-owner putting king bearings in the car. Rather do it myself to know it was done right with quality parts. Given the rising prices of S54s, I'd always immediately do rod bearings when buying an E46...and even an E9X.

Completely agree - its just part of the game at this point.

[EthanolTurbo]

A reminder that there are people who seriously believe and try to convince others that rod bearings needing replacement is a myth. 😜

[sd561]

Lesson learned the hard way for me. I should have gotten them done. The dealer had the service done in preparation for eventual sale, which was to me. @104k.

10k trouble free miles, including initial 2600mi delivery drive coast to coast, 4 flawless blackstone reports and 2.5y later, on a whim really, I scheduled the service, knowing it had effectively just been done but wanted peace of mind. I got spooked starting the car last winter when I heard a very brief cold start rattle.

the mystery shop dealer hired reinstalled the rod caps —backwards — on 3 of 6 cylinders. bearings for cyl 1-5 looked brand new still. cyl6 was torched but didn’t spin. Engine out or new s54 and I chose the latter. Slapping in new bearings and sending it wasn’t tenable for me. Huge L.

If you’re not sure, just get it done.

[Keith_MN]

A reminder that there are people who seriously believe and try to convince others that rod bearings needing replacement is a myth. 😜

Same with vanos. Just saw a 35k car with broken hub tabs. Some people seem to go out of their way to convince others that anything under ~100k is fine.

[4getr34]

Just a data point for everything we already know, and for anyone "one the fence" about doing the bearings. When I picked mine up a few weeks ago, I took it directly to a shop to have the VANOS and rod bearing done, glad I did. Really just a reference info...

Cheers,

to the untrained eye - what on this image indicates a bad bearing?

[Tbonem3]

Nothing. They look great for 88k, and no, they don't need replacement. Prob go another 88k in all honesty. But you're not allowed to say that, you must submit to fear.

Does anyone have any idea how many s54, S65 & s85s are out there on stock bearings? The enthusiast population replacing bearings early is very small.

[~CSL~]

to the untrained eye - what on this image indicates a bad bearing?

While I have no interest in debating “good vs. bad”, I’ll give you my thought process - from a strictly technical perspective these are not “bad”, top of cylinder 2 is showing early stages of wear, as the Babbitt has started to wear through and you can see the copper underneath. But no, not “bad” per se - but the reframe is from “unknown” to “known”, and what’s that worth to you? For me, this is a car with two previous owners, neither of whom I know and is over 20 years old; all I have is a “mostly” intact service history, that’s it. My approach is to eliminate as many variables as possible for my owner experience - the price I was willing to pay for the car was factoring this in.

I sent it to a shop that races and works on E46 M3s extensively and had them do the Vanos, Rod Bearing and Guibo directly this was all pre planned,. Over time I will continue to pick off and address whatever I deem as an appropriate PM for my car, because it’s what I choose to do with my time and my money - everyone gets to make their own decisions.

tldr; bearing were not bad, I chose to PM them and the Vanos to move an unknown to a know.

Cheers,