Crank issues during engine rebuilt

rick881

New Member
Mar 31, 2019
5
0
0
Ride
335i e90
hi all,
im in the middle of my engine rebuilt. At the start of June my car (335i 2009 e90) start smoking a lot after removing 2nd cats. Meanwhile I ordered a s363 borg warner speedtech kit to remedy smoking (i had one turbo seal gone). After 2 months waiting i got vanos exhaust code after a long highway pull (full bolt on on map2 jb4) and when i opened my oil filter i found full of metal shaves.
Took engine out and removed oil pan. I got 2 main bearings gone, but the others looks in good condition.
I found n.5 rod bearing with a +0.25 bearings, and crank machined only in that side to a +0.35. Got 49.67mm there and 50.02 in the other rods
Main bearings was kolbenschmidt +0.25
When i bought this car, i know it had a complete head rebuilt under bmw warranty, with 2 cams, 2 vanos, all valve etc replaced but in 2014 at 60k km, now i have 105k km.
In my opinion, previous owner spun bearing on piston 5, sold the car to the dealer who sold me, they machined crank to +0.25 (+0.35 lol) and all main bearings to +0.25 (dont know if they were std originally).
All maintenaince was done by me in the car, all the stuff in the engine looks like new expect for that.
I bought all the parts to rebuild the engine with a friend of mine who's a 10year master technician.
We bought a set of kolbeschmidt main bearings +0.25 to try if they fit well, but after torque the bedplate down, the crank didnt move, not even with a wrench. We tried many combination for bedplate torquing without success. A local shop found that crank was "oval" because on n.3 and n.4 bearing seat on crank were 5cent ouf of circle.

Thinking of many solution/causes of this.
Bent my crank when spun bearings (but it was very light damage and stopped the car immediatly)
The dealer machined the crank to +0.25 without termic treatment and crank deformed in the 10000km i drove
Dealer put a kolbenschmid +0.25 bearings without using right bmw colours causing bad clearence
Me and my friend installed the bedplate without using alignment jig (we didnt know the existence of it)

Anyone can direct me to a possible solution? i dont know where to hit my head lol
I will buy a new oem crank directly for german since i live in Italy (and sorry for my bad english)
DO you think I have to bore and realigne holes before install new crank?
I have the italian dealer for King bearings 100km from me, but dont they use color for main bearings?

thanks to all
 

colo_evo

Corporal
Jun 6, 2017
159
111
0
Ride
E90 335i MT
Start over completely with an engine from a junkyard.

Way to many people have touched that engine.
 
  • Agree
Reactions: Jeffman