[carguy138]

In the process of swapping motors and wondering what to do about the oil cooler in the wheel well. I experienced a spun rod bearing and possibly a main bearing and had the normal glitter bomb in the oil filter housing. There were a ton of magnetic metallic fragments that most likely came from the crankshaft.

I used my Motive power bleeder to push 4 quarts of Honda ATF through the oil cooler and then another 5-6 quarts of 5w-30 in both directions. After the oil ran through the cooler I had a magnet on the end of the line so all "waste" oil washed over the magnet. Zero metal particles were picked up.

I figured I would be good to go reuse the oil cooler but came across this TSB that has me second guessing what I did.

The BMW TSB 11 02 20_ENGINE REPLACEMENT AND ENGINE REPAIRS states "If the lubrication circuit is contaminated with metal fragments, then the oil cooler and the oil cooler lines need to be replaced. Cleaning these components will not be effective."

Any suggestions?

[feuer]

I would not and have not without any adverse effect. Besides you clean that oil cooler well.

[carguy138]

Originally Posted by feuer

I would not and have not without any adverse effect. Besides you clean that oil cooler well.

So re-using the oil cooler in this case should probably be OK?

I've already installed all new turbo oil lines and flushed the turbo as well. nothing in there either.

Since the new motor has new bearings and rings, I'm going to do a proper break-in. For the first start-up I plan to bring RPMs up to 1,100 for several minutes and let it get up to operating temperature, then drain the oil. Then will drive moderately for the first 1,000 miles with a few oil changes in between as well to flush any debris.

For oil, should I use non-synthetic to help the rings seat? On my last built motocross engine, the engine builder was adamant about not using synthetic early on for this reason.

Thanks

[335i54n]

will you see any negative effect in your ownership life, probably not. its such a low expense to get a used one or upgrade, why not at this point imo.

https://drivenracingoil.com/c-138919...mbly-oils.html

[witty]

probably not, its recommeneded to change your oil during your bearing breaking in period anyways, so after 500miles you can do your oil change and see if there's any metal residue left in your oil filter, most of the time, they will just end up on your oil pan.

[iqraceworks]

I would just clean it out..no need to replace it.

[feuer]

Originally Posted by LtxDavies

Rod bearings are a typical wear item and more critical on highly stressed engines like a tuned N20 or N54. Although these engines do not rev very high, more mileage with additional boost will eat into bearing life. On our Project 335i we decided to replace the bearings before adding serious power and were surprised to find significant wear at 82,000 miles. Track your bearing wear with regular used oil analysis and plan on rod bearing replacement some time in your engine's future.”

Oil analyzes will tell you very little if any info in respect to rod bearings on these particular engines. Whole deal is nothing more than forum anecdote. Please remember : perfectly healthy bearing can fail at any given point in time for many different reasons. Also opposite applies. Damaged bearing can last quite awhile.

[M-technik-3]

I would, the previous owner of my 88 Alpine Weiss M3 had built an 2.5l out of the 2.3 after it spun a rod bearing and bunch of metal ended up in the oil cooler. Needless to say the 2.5 suffered premature bearing wear and it died after a shot life.

I bought it for short money an put a rebuilt 2.3l that got a new oil cooler. I cut the end cap off and checked it out. Wished I could find the hard drive with the pictures I have of it.

[carguy138]

Thanks for the replies everyone.

How does debris get past the filter? I can understand if it went on for a while or the filter collapsed? In my case, I changed the oil/filter prior to a track day and the bearing spun during the second session. So it all happened pretty quickly.

Looking at the oil circuits, the oil is sucked up from the sump and passes through the oil filter. Then if the OFH thermostat is open, the oil passes through the oil cooler but if it's closed, the oil looped back to the top/bottom end?

Any info is much appreciated.