Rod Bearings = engine out and overhauled discussion

[tominizer]

Was having a lengthy discussion (of which I'm no expert in this area at all) about the S54 rod bearings. Mechanic guy I know that use to work for BMW says that to actually do this job right, you should pull the motor and overhaul it completely.... pistons, rings, etc. AAaaaaaand that's a LOT more work than dropping the pan and gettin' her done from the underside. Aaaaaand a LOT more money.

I just was curious as to what people really think about this direction of a complete pull and over-haul when addressing the rod bearing issue. Total over-kill or ?? And listen, once again, I'm a total motor rookie so I can't speak to this issue very well. But I'm interested in learning about the issue and will continue to read up on it as well.

[steffenme1]

There are a TON of threads around the bearings, and a lot of really good resources out there but if you're not having any other problems pulling the engine to do it just to do the pistons/rings/etc seems like a bit of overkill.

I'd also ask why are you doing the bearings? Are you getting high lead lead levels or just as a preventative measure? Any other engine issues you're trying to solve? How many miles on your Roadster?

[tominizer]

No signs that I've found yet. I have 108000 km. But I know people that have had issues a lot sooner as well with these bearings, and their oil analysis showed nothing (which surprised/worried me). So now I'm thinking of doing this job sooner than late just to be safe on my 2007 Z4M roadster.

And pulling the engine based on some of the reading I'm doing did seem like massive over-kill and got me wondering more about it Pretty big job. But what I'm wondering is this...... is it possibly the right thing to do ?? Is it really fixing the problem just pulling off the pan and doing the repair from the underside and that's what I'm looking into now as I'm keeping this car for the long haul.

I was reading this and it's what got me thinking:

https://www.langracing.com/finding-a...aring-failure/

[proboner]

Relatively new to these motors, but full engine rebuild sounds quite overkill. Just do the bearings with the motor in the car and do oil analysis from a known state. It's hard to put a ton of faith into the oil analysis when you're not actually sure where you started.

[pyshin]

Complete overkill and unnecessary.

A quick search on various forums about the S54 will show the weak points as the VANOS and rod bearings.. I haven't seen someone pulling the entire engine as a preventative measure; if they do it's to build the motor for track use.

[yousefnjr]

Definitely overkill, sounds like this dude wants your labor dollars

[bwright657]

Unless you're going to build a race car and have Lang Racing do the work, a full rebuild is overkill. Otherwise, you'll be fine with WPC treated bearings.

My car has similar mileage to yours (70k miles = 112k km) and I'll probably do the rod bearings closer to 100k miles or when the oil pan gasket leaks, whichever comes first.

[XMetal]

Lang Racing swapped my bearings - done from the underside. He didn't even mentioned or suggested an engine rebuild.

[Sergio19]

I wouldn't worry about it. There are M3's with 200k miles on original bearings.

[ANILE8]

Gonna drive mine till she blows then LS swap her.

[CTMP4me]

I just did my bearings this spring at ~110K km (before winter storage, Blackstone analysis in fall 2019 came back with elevated lead and copper for the first time). Cylinder 2 and 3 bearings were well through the copper layer, potentially a track day away from a spun bearing, car did around 30-35K km at the track on OE bearings.

If the car is only summer driven, warmed up thoroughly, and not tracked, feel free to push the interval. IMO 80-100K km is a reasonably safe interval if you track the car / motor literally spends 50% of time above 5K rpm.

[XMetal]

Originally Posted by CTMP4me

If the car is only summer driven, warmed up thoroughly, and not tracked, feel free to push the interval. IMO 80-100K km is a reasonably safe interval if you track the car / motor literally spends 50% of time above 5K rpm.

Mine was only summer driven (Southern California weather...so same thing ), warmed up thoroughly, and not tracked. They weren't pretty at about 52K miles.