[TheClaw]

Hey all, I'm looking for some advice. I am approaching 70,000 with my M235i and am preparing to do some sort of precautionary work done as far as the longevity of the car. My shop which I trust and have done all of the work on my car tells me I should get new "race" rod bearings since I plan on keeping the car.

Is this the right call?

Keep in mind I have been great with service on this car and timely oil changes every 4k or 5k miles. But I have been running the car with at least Stage 1 tunes since 22k miles. Thank you!

[XutvJet]

I wouldn't waste my money. The 2014+ EWG N55s don't suffer from rod bearing issues unless you track on high G road courses. The bearings in these motors are from the S55 and the crank in the M235 is forged and the motor has additional oil squirters.

[Cos270]

I’m coming up on the same mileage and from all my research I think upgraded bearings are a waste unless you’re going to track the car or are pushing huge power.
I just plan on doing spark plugs, pads and rotors (depending on wear) and changing my Mickey Mouse flange to the metal version. Maybe a crank seal guard if I feel like it.

[mecheng77]

Originally Posted by XutvJet

I wouldn't waste my money. The 2014+ EWG N55s don't suffer from rod bearing issues unless you track on high G road courses. The bearings in these motors are from the S55 and the crank in the M235 is forged and the motor has additional oil squirters.

I’ve never heard of the M235i having the S55 bearings, yes it has the forged crank.


OP: if you need to change your oil pan gasket then yes put aftermarket bearings but otherwise leave them. Only track days put extreme strain on them due to poor oiling

[XutvJet]

Originally Posted by mecheng77

I’ve never heard of the M235i having the S55 bearings, yes it has the forged crank.

All EWG N55s get the S55 rod bearings and forged connecting rods. Only the N55 in the M235 and M2 get a forged crank.

[mecheng77]

Originally Posted by XutvJet

All EWG N55s get the S55 rod bearings and forged connecting rods. Only the N55 in the M235 and M2 get a forged crank.

That doesn’t make sense, the M235i and M2 have EWG

[Kernel Kurtz]

There are MWG N55s that probably have neither.

[mecheng77]

Originally Posted by Kernel Kurtz

There are MWG N55s that probably have neither.

Yes the 335i

[XutvJet]

Originally Posted by mecheng77

That doesn’t make sense, the M235i and M2 have EWG

All 2 series M235s and N55 M2s have electronic wastegates (EWGs). Save for a few oddball BMWs like the X3, all 2014+ N55s are EWG. ALL EWG N55s use the S55 rod bearings and S55 forged connecting rods. Or you could look at as all S55s use 2014+ EWGs N55 rod bearings and connecting rods.

The pre-2014 N55s had pneumatic wastegates and weaker rod bearings that were somewhat prone to spinning.

The only N55s to use forged cranks are the N55s found in the M235 and M2.

All this information is gathered from RealOEM.

[mecheng77]

Originally Posted by XutvJet

All 2 series M235s and N55 M2s have electronic wastegates (EWGs). Save for a few oddball BMWs like the X3, all 2014+ N55s are EWG. ALL EWG N55s use the S55 rod bearings and S55 forged connecting rods. Or you could look at as all S55s use 2014+ EWGs N55 rod bearings and connecting rods.

The pre-2014 N55s had pneumatic wastegates and weaker rod bearings that were somewhat prone to spinning.

The only N55s to use forged cranks are the N55s found in the M235 and M2.

All this information is gathered from RealOEM.

M235i vs 2011 335i which has pneumatic waste gate

Realoem shows identical parts except for the crank. Rod and piston are identical!!

Click on any of the M235i bearings and you will see how many cars they are used on!

[mecheng77]

Originally Posted by mecheng77

M235i vs 2011 335i which has pneumatic waste gate

Realoem shows identical parts except for the crank. Rod and piston are identical!!

Nothing unique about the bearings