A Tale of Two Engines...Rod Failures

[MPACT]

Hello all. I had an engine fail 100mi after installing an ESS S/C on my 2011.75 M3 with 67k miles. Upon inspection, it was a failure of #1 and/or #5 rods. See pic below.

After swapping to another donor engine with 20k miles it popped again. I just bought another 25K mi donor engine but want to figure out what is going on before installing this one.

So, please any suggestions as to what may be happening would be greatly appreciated!!


Anyone seen this?


2022 Update:

Adding some context to this since I think I figured out what it was. So first engine, original at 67K miles, just let go with a standard rod bearing failure. Super bad luck but that is what it was.

After that I picked up a 20k mi donor engine and had a shop in SLC do the work. The guys there really botched that job, leaving several things wrong with the engine install and it went at 200mi post-install. Very bad news, shop refunded me all the money and took responsibility. I thought many times about selling the car, building a stroker, or just trying to decide what to do. I ended up just scrapping both engines and starting over.

I ended up buying another 25k mi donor engine, this time I went through the whole thing, changing rod bearings to coated OEM, changed all the gaskets, and then I took it to a high-end shop in UT and had it all put back together as an NA setup. I then moved to TX and had MPorium go through every detail to make sure the car was mechanically perfect. Since then I have put ~15k miles on it just to make sure it was all running fine. Changed water pumps, thermostat, throttle actuators and added all the upgrades. Ended up getting one of the last Harrop kits and being invited into the Stage 2 beta group.

[Green-Eggs]

In this engine, your main bearings look like they failed first and threw debris into the #1, #5 rod journals. That's why they are destroyed too. Superchargers do put extra load on the #1 main bearing. We've seen this same failure before. If your previous motor failed on the same two rods, it's very likely also caused by #1 main bearing failure too.

[kawasaki00]

I was going to say that main bearing look smoked. When both rods are in the same condition main bearing failure was first.

[CSMRX7]

What PSI and tune were you running?

[opihi5]

Sounds like you need to find yourself a new car..

[pbonsalb]

Lets say one wants to rebuild the motor for boost. What change would be made to the main bearings?

[MPACT]

Green-Eggs: Thanks for your response. I know you guys see a lot of these. Any idea why I might have seen 2 main bearing failures with so little miles? (100mi and 200mi) Anything preventative we can do? I am working with the shop to see what ideas they have.

This was the ESS 625 kit. Stock ESS tune, with the "altitude" pulley, I was seeing ~6psi at 5000'.

And yes, I am really wondering if I should just "start over". I already sold the ESS kit, and will be going NA stroker I think if I can figure out what is going on. Either way, I need to fix this.

[Mvy]

Did you use the same ESS kit on both motors? If so it seems something might have been up with your kit?

[MPACT]

Yes, same kit.

[Patrón]

I don't believe much in coincidences but there is two variables, 1) the original motor may have had bad bearings and the blower amplified the problem. 2) the installation of the bearings could have been incorrect. Can you share the experience of the person that did the install on the bearings? How many have they done on s65 motors, how many on other s motors?

[deansbimmer]

I agree that the main bearings look like they failed first and took out the rod bearings. Out of the dozens of S65's I've dismantled for parts, the only two with failed mains were supercharged with failures that looked just like yours. I believe the blower pulley simply places too much radial force on the crankshaft and it overworks the first main.

While I am a huge fan of blowers I have not installed one on mine just because I don't want to gamble. If I were to install one, I would also install VAC's coated main bearings if I could get the clearances right. If someone would engineer some type of girdle to support the crankshaft in supercharged S65's, I believe we'd see fewer of these main failures.

[MPACT]

This was the first S65 for this shop, they usually do Audis and Lambos. They currently run in PWC with a couple of Huracans.

[deansbimmer]

There is a very good chance that the engine block is ruined. When the main overheats like that it cracks the block journal at the oiling hole.

[MPACT]

Originally Posted by deansbimmer

There is a very good chance that the engine block is ruined. When the main overheats like that it cracks the block journal at the oiling hole.

That is what I am worried about. We will have the crank out today but with the heat discoloration I already see around the main bearing, I am not loving the idea of reusing the block but didn't want to ditch it if it wasn't bad.

[Properstyle]

I really think that was a improper bearing install. 1200 miles and pop on 25k mile motor. What oil were you using. what weight.

[MPACT]

Factory BMW Oil. Yeah, I am thinking that too, I just am used to seeing improper bearing install not even last 1200mi, but I am not familiar with S65s before this.

[MPACT]

So I just heard back from the shop. Engine block #2 is also done. So 2 complete engines down. That is enough for me, time to buy a P-Car with warranty. The part out begins: http://www.m3post.com/forums/showthread.php?t=1311693

[Patrón]

Originally Posted by MPACT

So I just heard back from the shop. Engine block #2 is also done. So 2 complete engines down. That is enough for me, time to buy a P-Car with warranty. The part out begins: http://www.m3post.com/forums/showthread.php?t=1311693

I'm sorry to hear. Good luck. Do you think the shop messed up the install, if you had to guess?

[X5-User]

Damn man...2 engine failures due to supercharging...

[kawasaki00]

Had nothing to do with improper install of the rod bearings when the main bearings is cooked. Even if they were installed wrong that has nothing to do with the mains

[Mvy]

Could the kit have been giving boost out higher than expected or other type of problem with the supercharger pressure release system? I know the OP said he ruled out over pressure, but twice with the same kit??This cant be normal as there are lots of ESS users who mash on their cars with that kit on all day long and this doesn't happen. Sure, adding a SC may increase engine wear,but this is not normal.

[Patrón]

Originally Posted by Mvy

Could the kit have been giving boost out higher than expected or other type of problem with the supercharger pressure release system? I know the OP said he ruled out over pressure, but twice with the same kit??This cant be normal as there are lots of ESS users who mash on their cars with that kit on all day long and this doesn't happen. Sure, adding a SC may increase engine wear,but this is not normal.

a member posted that it's the force applied to the main pulley, that is why #1 and #5 mains are what failed. this is the first that i've read where the blower pulley, tensioners and belt have caused wear or stress at the main pulley. spinning the blower pulley is pretty easy, don't imagine it could cause that much stress unless the tension is extreme compared to stock.