Rod Bearings?

[TopJimmy]

Originally Posted by sly1types

Thanks, I just ordered all the colors of the OE rod bearings hoping that its just some worn bearings. Plan is to pull it apart in the new couple weeks. I couldn't find all the colors of WPC coated ones in stock.

Talking to some people it could be a bent rod, but unlikely with stock turbos and good tunes, my tunes torque don't come on too early and i never hit it below 3k rpms...

In the event of a bent rod i'm going to do some Forged CP pistons and Forged Corrillo rods from Lang Racing then put in some supertech springs and have the head gone through and ported/polished.

How did your built engine turn out? Any pointers or things you wish you would or wouldn't have done?

CP sounds like a good plan if needed. My only suggestion is to keep all stock sizes instead of going "wider clearances" (wall gap and rings), which reduces daily drivability. On the head no real need for CNC but a HG Pocket Port R would be perfect.

[papasmurf_m3]

Originally Posted by sly1types

Looks like I might be needing some rod bearings. I just started tracking this car last year, so maybe 12 days. It's a 2016 that I bought in 2018 with like 28k miles. It has been tuned since 35k miles.

So frustrating, I didn't think this car would have the rod bearing issues like my E46M3. Also I have been doing oil samples on the X5m.

What's the go to bearing replacement on these S55s?

Did you change the oil and check again?

Did you say you heard knocking sound?

[sly1types]

Originally Posted by TopJimmy

CP sounds like a good plan if needed. My only suggestion is to keep all stock sizes instead of going "wider clearances" (wall gap and rings), which reduces daily drivability. On the head no real need for CNC but a HG Pocket Port R would be perfect.

I would only do the head work because a good buddy owns a big performance head shop…

[sly1types]

Originally Posted by papasmurf_m3

Did you change the oil and check again?

Did you say you heard knocking sound?

No ticking or knocking sound. I filled it back up with fresh oil and filter, but will only be starting it to put it on and off the trailer when I take it to the shop next week.

Plan is to have them pull the pan and see what the bearings and rods look like and go from there. I have all the colors of the OE rod bearings ordered.

I don't want to risk driving it around and ruining the crank or block. This car is will be hitting the track for 20-30 sessions and i don't want to risk it.

[Gunzy]

When you drained the oil pan was there similar debris present?

[sly1types]

Originally Posted by Gunzy

When you drained the oil pan was there similar debris present?

Nope, looked great when it was draining. This is all metal that didn't make it through the filter…so the filter was doing it's job

[Gunzy]

Were you able to see Shavings in the filter? Curious to see how the bearings look when you dive in. Report back after tear down.

[papasmurf_m3]

I've seen and heard it looks normal.

If you were messing things up you would have started knocking already. the moment you get metal to metal contact it's done. You will hear it.

If you do take things apart. Make sure those rod bolts are not one time use stretch to yield...

I've seen people take bearings out and they look fine but, people start fear mongering look how scuffed etc etc.Uhhhm, Its a bearing.... They all look like that. It's fine. As long as there is no copper flake you're good.

Or simply drag your nail across the bearing if it doesn't catch your good.

GL. But, think you'll be fine with the oil change.

Cheers!

[sly1types]

Maybe this is "normal" as the engine gets older. This is what blackstone said. I took a baby spoon and shoveled like 10 scoops the metal oil in the sample jar.

Not sure what my plan is now

[IamFODI]

Originally Posted by sly1types

I took a baby spoon and shoveled like 10 scoops the metal oil in the sample jar.

AFAIK this kind of oil analysis is blind to particles that are big enough to be seen. There are wear modes that’ll produce particles that big without generating particles small enough for this kind of oil analysis to catch.

(Not that I have any idea what’s going on in your engine of course)

[sly1types]

So here is what the bearings look like and here is my oil history.

[IamFODI]

That discoloration looks like the same stuff we E9x folks observed that turned out to be superficial – i.e. not "the last layer before they spin."

If you / your boy still has those bearings, try sanding down the discolored parts. I bet the discoloration will go away before you hit copper.

[hC1001]

Originally Posted by sly1types

So here is what the bearings look like and here is my oil history.

Wouldnt plasti gauge be the best method to determine if bearings are actually worn?

The pic of the bearings on their "last layer before they spin" dont look bad at all but im no expert.

[brad65ford]

great thread with a lot of good posters here. I'm on my 3 S55 motor (1 m3 and 2 M2 comps) never thought much into this but having now had a few new high performance cars and taking apart their filters from the first oil changes to see a lot of metal shaving in the filter pleats,, its a little scary. But we all understand this is normal but there shouldn't be any more after the 2nd or 3rd oil change..... Which leads me to my newest 2020 M2 Comp that had 11k miles and 2 pervious oil changes before my 3rd. Today we opened up the filter and seen a small metal flakes in the pleats, and they are magnetic. One would think there wouldn't be any metal flakes at 12k miles and 3 oil changes so I'm a bit concerned. Going to purchase another oil filter and see what it looks like after 500 miles.

[TOXIC.M4]

please advise rod bearing bolt torque, was trying to find out bolt torque value but but w/o successful result. I will do rod bearing inspection and if bearing are good will put them back with same bolts. please advise if you know required tension.

[BzsBimmer]

Originally Posted by TOXIC.M4

please advise rod bearing bolt torque, was trying to find out bolt torque value but but w/o successful result. I will do rod bearing inspection and if bearing are good will put them back with same bolts. please advise if you know required tension.

Please do not use your same bolts. These are TTY bolts and should be new.
Do it right or don’t do it at all.

You can find torque + angle through ISTA IIRC

[NickyC]

Shows you how reliable the S55 is when we need to start bringing up rod bearings in a quest for something to worry about.

This ain't the S54 (even the issues with that motor are vastly overstated). Relax.

[BzsBimmer]

Originally Posted by NickyC

Shows you how reliable the S55 is when we need to start bringing up rod bearings in a quest for something to worry about.

This ain't the S54 (even the issues with that motor are vastly overstated). Relax.

Totally agree… have said this from day 1.

[TOXIC.M4]

Originally Posted by BzsBimmer

Please do not use your same bolts. These are TTY bolts and should be new.
Do it right or don’t do it at all.

You can find torque + angle through ISTA IIRC

many thanks for reply. will try to describe reason, the car has 12k miles, I owner, so car engine was tested on auction if it runs or not and due to car was w/o thermostat during start all oil was thrown out, as I assume engine was running few seconds but enough for doubts, after purchase when I drain remaining oil there was about 2 ltr of old oil.... after oil and filter replacement car was running 50 km or less. I open engine cover due to valvetronic motor has fault. we found that intake camshaft needs replacement, however oil filter is clean w/o any metal particles. that's why I want to know condition of rod bearings.

[IamFODI]

Originally Posted by TOXIC.M4

many thanks for reply. will try to describe reason, the car has 12k miles, I owner, so car engine was tested on auction if it runs or not and due to car was w/o thermostat during start all oil was thrown out, as I assume engine was running few seconds but enough for doubts, after purchase when I drain remaining oil there was about 2 ltr of old oil.... after oil and filter replacement car was running 50 km or less. I open engine cover due to valvetronic motor has fault. we found that intake camshaft needs replacement, however oil filter is clean w/o any metal particles. that's why I want to know condition of rod bearings.

Not that I’m the guy to ask, but I feel like I’d want to tear the engine all the way down in this case.

[BzsBimmer]

Originally Posted by TOXIC.M4

many thanks for reply. will try to describe reason, the car has 12k miles, I owner, so car engine was tested on auction if it runs or not and due to car was w/o thermostat during start all oil was thrown out, as I assume engine was running few seconds but enough for doubts, after purchase when I drain remaining oil there was about 2 ltr of old oil.... after oil and filter replacement car was running 50 km or less. I open engine cover due to valvetronic motor has fault. we found that intake camshaft needs replacement, however oil filter is clean w/o any metal particles. that's why I want to know condition of rod bearings.

Seems justifiable enough I guess, however, if going through all of that, why cut corners and reuse bolts that countless engineers and material scientists have concluded that certain bolts should be one time use, therefore given the TTY classification?

[FaRKle!]

Originally Posted by TOXIC.M4

please advise rod bearing bolt torque, was trying to find out bolt torque value but but w/o successful result. I will do rod bearing inspection and if bearing are good will put them back with same bolts. please advise if you know required tension.

With oil on the bolts the spec is 20Nm + 70deg, then another 70deg for the con rod bolts holding the cap to the rod. As BzsBimmer mentioned, use new bolts (old bolts are OK to use if checking with plastigauge).