Cracked engine block on ESS G1 kit M3

[Andrew T.]

Hi guys, I bought a 2010 E90 DCT M3 3 years ago with everything stock and 100k miles on it. Till today I have drove another 35k miles. For the modification, I’ve installed ESS G1 kit with ACL rod bearing and ARP bolts around 120k miles. I’ve only tracked it once on DEC, 2020. Change oil every 4000 miles.

Few days ago, I went for a tire change and found oil leaking which never happened before. After some inspection, we found a crack on engine block as shown in the picture.


So far me and the workshop guys are still discussing whether welding the crack will work or changing the whole block is needed. (Or maybe find another engine with lower mileage)

Also, we are still looking for the cause of cracking.We have many other E9x M3 with similar setup locally and no other vehicle had this happened before. However, they are all with ESS 625/650 kit, mine is the first new generation ESS kit here. So we are now suspecting whether the new blower cause the problem or just another unknown reason. Any opinion or suggestion are welcomed.

[Redd]

Is there a bolt/screw or bracket near there? Over torque?

[alfalfa]

You can drive it until it's complete junk but you can not save it anymore. Welding will also not work.
When the block is cracked you just can reuse it as a table.

[Andrew T.]

Originally Posted by Redd

Is there a bolt/screw or bracket near there? Over torque?

Yes, originally there’s a bolt to hold the generator. And the ESS G1 kit uses a longer screw on the same hole to hold the supercharger, too. But we followed the instruction to install the supercharger, so it shouldn’t be over torque.

[Andrew T.]

Originally Posted by alfalfa

You can drive it until it's complete junk but you can not save it anymore. Welding will also not work.
When the block is cracked you just can reuse it as a table.

So we can only replace the whole block? That’s quite some money though…
But we still want to find the cause of the crack to make sure it won’t happen again on the new block

[Redd]

Originally Posted by Andrew T.

Yes, originally there’s a bolt to hold the generator. And the ESS G1 kit uses a longer screw on the same hole to hold the supercharger, too. But we followed the instruction to install the supercharger, so it shouldn’t be over torque.

Looks to me like something heavy hanging off that corner caused the crack. Maybe due to vibrations or maybe there was just a defect in the block casting which gave way when you hung the supercharger off that bolt hole.

[drrust]

There was an extensive discussion on welding blocks.

Broke down my engine block and god knows what else https://www.m3post.com/forums/showthread.php?t=1851485

Even though one can find weld repaired blocks on EBay,on has to question the soundness of the weld. Welding aluminum requires really clean surfaces. One likely couldn't get it clean enough with the motor fully assembled.

As an example, Deansbimmer refurbishes oil pans. The pans are ultrasonically cleaned then baked prior to any welding. If one did that to a block the engine would need to be disassembled. At that point there would be significant labor involved and it would seem foolish to reassemble with a questionable block.

[Andrew T.]

Thanks for all the reply. Seems like the only way for me is to buy a new block and other stuff to rebuild my engine
The cost of buying an used engine is pretty much the same.
We will take a close look into the crack after we disassemble the engine. Hope it’s not the extra weight of the supercharger.

[Nebo]

Originally Posted by drrust

There was an extensive discussion on welding blocks.

Broke down my engine block and god knows what else https://www.m3post.com/forums/showthread.php?t=1851485

Even though one can find weld repaired blocks on EBay,on has to question the soundness of the weld. Welding aluminum requires really clean surfaces. One likely couldn't get it clean enough with the motor fully assembled.

As an example, Deansbimmer refurbishes oil pans. The pans are ultrasonically cleaned then baked prior to any welding. If one did that to a block the engine would need to be disassembled. At that point there would be significant labor involved and it would seem foolish to reassemble with a questionable block.

Worth mentioning from the linked thread that it's not just aluminum but an alloy and that makes it even more unadvisable.

[Pedalkick]

Maybe a bolt that was too long was tightened too much pulling up the threaded section?

[amrazM]

send bracket back to ess i think the bracket might have been defective which was putting an uneven force to that mounting point which holds the majority of the torque

[jp1984]

do you have a picture of the bracket?

[Andrew T.]

Originally Posted by Pedalkick

Maybe a bolt that was too long was tightened too much pulling up the threaded section?

We have measured it but the bolt hadn't even touch the end

Originally Posted by amrazM

send bracket back to ess i think the bracket might have been defective which was putting an uneven force to that mounting point which holds the majority of the torque

Sad news is that I live oversea and it would take a long time to send the bracket to ESS for an inspection.

[Andrew T.]

Bracket looks normal though.

[tom @ eas]

Your kit wasn't purchased from us but I did forward a copy of your post to ESS, hoping to provide a bit more info on this, and they were able to look into this a bit further.

The SC bracket isn't the case - the production goes through a number of documented QC checks during the CNC process - it's very unlikely one would get out that does not pass inspection, if at all. However, they would be willing to exchange the bracket/hardware if this is what you want for peace of mind.

Most likely this is a block defect that was exacerbated by the additional stress from the bracket and rotating assembly. IMHO - it's a fluke as there are literally hundreds of these kits out there - I've never experienced this before. Luckily, it is in the non critical location of the block and should be able to be TIG welded easily - so the engine shouldn't be compromised.

Please get in touch with me at the email in my signature and I'll get you in contact with ESS.

[SAMM3Y]

What a guy!! ^^^

[Redd]

Originally Posted by tom @ eas

Most likely this is a block defect that was exacerbated by the additional stress from the bracket and rotating assembly. IMHO - it's a fluke as there are literally hundreds of these kits out there - I've never experienced this before. Luckily, it is in the non critical location of the block and should be able to able TIG welded easily - so the engine shouldn't be compromised.

I also think a casting defect is most likely. Can Alusil be welded like normal aluminum? If yes and you intend to weld then might be a good idea to also weld in additional bracing to prevent it from happening again in the future.

[tom @ eas]

Originally Posted by Redd

I also think a casting defect is most likely. Can Alusil be welded like normal aluminum? If yes and you intend to weld then might be a good idea to also weld in additional bracing to prevent it from happening again in the future.

Alusil is a coating, only on the block surface. Engine block itself is aluminum.

[Andrew T.]

Originally Posted by tom @ eas

Your kit wasn't purchased from us but I did forward a copy of your post to ESS, hoping to provide a bit more info on this, and they were able to look into this a bit further.

The SC bracket isn't the case - the production goes through a number of documented QC checks during the CNC process - it's very unlikely one would get out that does not pass inspection, if at all. However, they would be willing to exchange the bracket/hardware if this is what you want for peace of mind.

Most likely this is a block defect that was exacerbated by the additional stress from the bracket and rotating assembly. IMHO - it's a fluke as there are literally hundreds of these kits out there - I've never experienced this before. Luckily, it is in the non critical location of the block and should be able to be TIG welded easily - so the engine shouldn't be compromised.

Please get in touch with me at the email in my signature and I'll get you in contact with ESS.

Thanks for your help! Right now they are still tearing the engine apart. Due to the crack is too long, removing the whole block to weld might be needed. So I am thinking to install a new block though, god knows how many defect I have on this one

IMO, buying a engine and install it might save more time for me. However it’s hard to find an engine in good condition and low mileage with reasonable price in my current location…

[tdott]

Do you have a more zoomed out picture of the crack? Trying to picture where on the block that is.

[alfalfa]

Originally Posted by tom @ eas

Alusil is a coating, only on the block surface. Engine block itself is aluminum.

Sorry but this is wrong!
Nikasil is a coating. The S65 block is complete Alusil.