Opened engine to find my worst nightmare... advice needed.

[Obioban]

Unless the tune turned them down, the knock sensors should protect the engine from detonation.

OP: what tune are you running?

Unrelated: I think you'll end up regretting fixing this engine instead of buying a used one.

[Syfon]

If you want to keep the same motor, that's a full tear down and rebuild. No way around it.

Of course the other option is to find a cheap s54, do the bearings/vanos and any other items needed then put it in your m3 and part out your current motor.

[Syfon]

This might be a silly question but how would you guys recommend removing my block? The head and the engine lifting bracket is off the car...

I was thinking just pull the front end off and slide it out with the trans right? Since there is no support bracket up top should I like... tie ratchet traps around my engine and into the crane hook?

I removed the engine/trans in my garage. Disassembled the entire front end and pulled the engine trans as one then broke them apart and started the process of tearing down the s54. Was a lengthy job and fun to see it all in pieces lol

[SteelGreyM]

Unless the tune turned them down, the knock sensors should protect the engine from detonation.

OP: what tune are you running?

Unrelated: I think you'll end up regretting fixing this engine instead of buying a used one.

I just have the build journal B-spec tune. It's worth noting that I had an e85 flex fuel kit. I never ran more than e65 and I never ran more than maybe 15 tanks of the stuff.

Before I sent build journal my file for the b-spec tune they made me scan my car with a BMW scanner and we found out one or more of my knock sensors was bad. I replaced all of them with new OEM. IIRC this was well before I started noticing any of these symptoms.

And yea ive decided against repairing this engine. Could I get it running? sure. Would I *really* be comfortable with it? Hell no.

Im going back and forth between 2 choices at the moment.

Choice 1: Just get a used, ~120k mile engine and slap that bad boy in after doing rod bearings and transferring my VANOS.

Choice 2: Get a good used block and pistons and rehone the block (NOT bore). Transfer my crank and replace rod and main bearings with OEM. Replace the piston rings with OEM. Replace head gasket with OEM. For the head, i'm gonna call up lang racing and get their opinion on it. Worst case scenario I buy a used good head. After that, all damaged pieces are repaired. Id basically have a brand new engine minus the pistons and block. I dont plan on running any boost so perhaps this is the way to go...

The only thing stopping me from doing choice 2 is the possibility that i'll mess something up somehow. But I have done tons of research and every other job ive done on this car has been a success because of the hours of research I do to make sure things go right. Id imagine as long as I triple check all my clearances I should be good.

[Obioban]

I’d say do choice 1 and go back to a stock tune to not repeat your experience.

[heinzboehmer]

Another vote for choice 1. Obioban any particular reason why you're implying the tune caused this?

[SteelGreyM]

I’d say do choice 1 and go back to a stock tune to not repeat your experience.

Why do you suggest choice one? Im certainly going back to stock tune and getting rid of the e85 setup. I havent had or heard of issues with headers so ill keep my headers.

What potential complications would there be from doing choice 2 as long as all clearances are accounted for?

Another vote for choice 1. Obioban any particular reason why you're implying the tune caused this?

I think he is saying that to eliminate any potential factors that have may caused this.

[Obioban]

Another vote for choice 1. Obioban any particular reason why you're implying the tune caused this?

It looks very possible there was detonation, and reasonable knock values would have stopped that.

[Obioban]

Why do you suggest choice one? Im certainly going back to stock tune and getting rid of the e85 setup. I havent had or heard of issues with headers so ill keep my headers.

What potential complications would there be from doing choice 2 as long as all clearances are accounted for?

It won't end up being cheaper once all the labor/parts are paid for, it won't have a power benefit, and it is more likely to have issues.

[SteelGreyM]

It won't end up being cheaper once all the labor/parts are paid for, it won't have a power benefit, and it is more likely to have issues.

After doing all the math it turns out it will be cheaper actually because I will be doing all the labor myself.

Just got off the phone with Andrew at Lang ring to get his professional opinion. He suggested I get my block bored out slightly, upgrade to slightly oversized pistons that come with new rings (CP forged. Its the one they use all the time in their builds.) My rods and crank are fine so keep that. After that just go with OEM rod bearings and king main bearings (clearances checked of course). He also said that while my head may be salvageable, its not worth the time and money to find out and that I should just get a new one.

Doing this would negate the price I would pay for a fresh block (that may end up having problems!) and used pistons.

I know this is probably not the smartest and most reliable idea but im confident that this can turn out okay. Something inside is telling me to just go through with this plan.

[heinzboehmer]

It looks very possible there was detonation, and reasonable knock values would have stopped that.

Makes sense.

[Arith2]

It looks very possible there was detonation, and reasonable knock values would have stopped that.

I did also have an engine blow with the B Spec tune. That engine wasn't in the great condition but the piston EXPLODED! I'm starting to become a skeptic.

[Icecream]

After doing all the math it turns out it will be cheaper actually because I will be doing all the labor myself.

Just got off the phone with Andrew at Lang ring to get his professional opinion. He suggested I get my block bored out slightly, upgrade to slightly oversized pistons that come with new rings (CP forged. Its the one they use all the time in their builds.) My rods and crank are fine so keep that. After that just go with OEM rod bearings and king main bearings (clearances checked of course). He also said that while my head may be salvageable, its not worth the time and money to find out and that I should just get a new one.

Doing this would negate the price I would pay for a fresh block (that may end up having problems!) and used pistons.

I know this is probably not the smartest and most reliable idea but im confident that this can turn out okay. Something inside is telling me to just go through with this plan.

Getting a good block and heads will be cheaper, smarter and more reliable than trying to salvage that one. If you wanted to 'build' a motor, then maybe use that one since you will be spending tons anyway and taking the risks with it. I am not an expert by any means once you start talking boring things out and rebuilding from the damage i see in the pics you are just going down a rabbit hole. You can probably find a good block near you head (with a spun bearing or something) for around 2k. Swap your crank over, new rod bearings and maybe a new head gasket for good measure and you're done for under $3000.

[sapote]

The chipped cylinder wall is above piston ring and so no issue. But from the photos I think here is what happened: gasket leaked between 2 cylinders which led to pre-detonation and damaged piston. The prolong hot exhaust gas leaking had been eating the thin section between cylinders on both block and head. This means they have to be measured and see if after resurface, the thickest head gasket is within spec or not. If not then you need another engine.

This detonation was caused by leaking gasket between cylinders and maybe not related to tuning.

[x Spades x]

Dude you are crazy trying to fix this. The cost will be almost the same as getting another engine (give or take $500-ish). Get a new block... toss it in, and call it a day. You need to be saving all of your money for a house, not dumping into this engine that MAY need additional parts .