E92 Rod Bearing rnr

[tighfitzgerald]

These are the rod bearing from 2011 m3 coupe. Previous owner said, “previous owner said they were done.” I dont know enough to say either way, but these are nothing like some of the horror show images being posted. Any thoughts apprciated.

[Redd]

They look absolutely fine to me. The wear surface is inside the curve, not outside.

[RocketyMan]

Seems like alot of junk got imbedded in the bearings. Not sure what I'd amount that to exactly other than dirty oil with physical contaminates. You can see the many black spots signifying this.

Maybe you're running a K&N air filter?

[tighfitzgerald]

Macht Schnell… Dude, I cant stop grinning. That call was spot on. Ill need to see about. Cool man, thx dude

[tdott]

Decent amount of wear, typically you don't want to see those dark spots.

If mileage is under 80k, it's pretty bad. Higher mileage, it would just be okay but not terrible.

[tighfitzgerald]

Originally Posted by tdott

Decent amount of wear, typically you don't want to see those dark spots.

If mileage is under 80k, it's pretty bad. Higher mileage, it would just be okay but not terrible.

136.6k mi

[nycplumber]

Originally Posted by tighfitzgerald

136.6k mi

I haven't taken apart many engines but I don't know any V8s that rev passed 8000 whose bearings will look that good after 136k miles

[Reddevils7]

Originally Posted by tighfitzgerald

136.6k mi

136k miles on the engine or on this set of bearings. You mentioned the previous owner did them, at what mileage?

[Eric335]

Originally Posted by RocketyMan

Seems like alot of junk got imbedded in the bearings. Not sure what I'd amount that to exactly other than dirty oil with physical contaminates. You can see the many black spots signifying this.

Maybe you're running a K&N air filter?

Dumb clarification for my sake: Is the K&N/Macht Schnell air filter comment a joke or are they somehow actually tied to contaminants in the bearings/oil?

[RocketyMan]

Originally Posted by Eric335

Dumb clarification for my sake: Is the K&N/Macht Schnell air filter comment a joke or are they somehow actually tied to contaminants in the bearings/oil?

No. Not at all.

K&N filters, and the like, let in more deposits into the combustion chamber by means of airflow over filtration when compared to OEM filters. You will get more deposits and "ceramics" mixed in the oil--such as elevated silicon, aka "sand" like substance or "dirt." You can see the pinholes through the media by holding up the K&N filter up to the light.

Then combine way too long of OCI with extra stuff floating around in the oil--I can see it happening as far as excess deposits in the oil.

[deansbimmer]

The date stamps on the back of the shells indicate late 2010 manufacturing, so that suggests they were original and never actually replaced as the sellers had asserted.
A prime example as to why it should be assumed that the work hasn't been done unless there's documentation. Good thing you went ahead with the service.

They do tend to have more debris embedment than usually observed.

[tighfitzgerald]

Originally Posted by Reddevils7

136k miles on the engine or on this set of bearings. You mentioned the previous owner did them, at what mileage?

It’s all hear-say dude… no records provided. I picked up the car with 131k mi and “he said that, he said, they were done” thanks for the reply tho, i love picking the collective brains of all you junkies!

[tighfitzgerald]

Originally Posted by deansbimmer

The date stamps on the back of the shells indicate late 2010 manufacturing, so that suggests they were original and never actually replaced as the sellers had asserted.
A prime example as to why it should be assumed that the work hasn't been done unless there's documentation. Good thing you went ahead with the service.

They do tend to have more debris embedment than usually observed.

I can rip.. err rest easily now that the $15k time bomb is reset. Thanks again, boys!