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

[SteelGreyM]

Anyone have an answer to number 1?

OP, did you check compression, if it held compression you may be able to get away without touching the cylinder walls, or maybe have it resleeved?

Yea general consensus is pre ignition. Which I agree with because I heard it happening.

I never had it compression tested because I was 1000% certain the headgasket was blown and I was removing it anyway. Part of me wants to bolt everything back up and compression test with the new head gasket. The other (and probably right) side of me is saying to just bite the bullet and do this properly with a new block and pistons.

Re hone and new rings will get you a better seal, not sure if you have go with different sized rings though.

I may just hot tank and re-hone the new block that I get and re use the rings on the pistons I get if thats okay. I figure while the block is out i'll have it cleaned up nicely

[Halftim3]

Re hone and new rings will get you a better seal, not sure if you have go with different sized rings though.

[Halftim3]

Anyone have an answer to number 1?

OP, did you check compression, if it held compression you may be able to get away without touching the cylinder walls, or maybe have it resleeved?

[SteelGreyM]

Thank you guys for all your input. I’ve already got a crane and all that and I’m fully prepped to do an engine swap. I had a feeling that this was pre detonation pitting. The head gasket had been blown a while and around 2500rpm I would always hear a tiny rattle. I never imagined it was head gasket.

I will probably end up buying a new bottom end. Since it was pre detonating does that mean my crank + bearings are toast?

I found an s54 block with pistons. I was debating going for that. Would I need to get new piston rings or can I just re use those rings? Is there a way to check how well they seal?

About the head... I’ll take it to a machine shop and get their opinion on it.

for now I think that’s all right? Just pistons, block, and maybe crank?

[Papermaker]

I don't see any evidence of detonation, if you have small pieces of aluminum on your plug center electrodes that would be a sign light detonation. If you had severe detonation your combustion chambers and piston would show pitting to actual holes through the pistons crowns. The larger danger is the forces applied to the rods and main bearings and to the crankcase. I also think that you'd have knock sensor codes.

[Kdubski]

You can probably just bore to +.20 and re ring with +.20 oversize ring. Consult with a local machine shop cause they'll advise you best.

[Speed Monkey]

Here is a ramble for your consideration... That chip in the cylinder wall, if it is above the 2nd piston ring’s sealing point against the cylinder wall @ TDC, the oil control ring will be properly shielded against hot combustion gas, which is what you want. The top two rings seal the combustion gases. If the oil control ring isn’t damaged, that’s good. I’m guessing just replace the beat up piston with a good used one. Knock down the sharp high spots on the head where it’s beat up, install a new head gasket, bolt it back up, and this is quite possibly the most minimum & ultra cheap way to repair your engine. If it explodes after a year, at least you’ll have a year to save up for a good replacement engine. 😁

[Titaniu//M]

Would agree with the others here. You wouldn't want to bore out the cylinder (even slightly) and reuse the stock pistons + rings because that will cause blow by issues at a minimum. Debatable whether that cylinder head is reusable based on the damage.

Most cost effective option is probably getting a used bottom end, cylinder head and a shop crane from Harbor Freight to swap it yourself. Bare minimum you can probably get away for around $2-3k. Similar thing happened to my old 335i when I walnut blasted it and let debris fall into one of the cylinders.

[erickhoyos]

Consensus would agree on getting another S54. Or perhaps a very familiar and popular LS V8 swap...?

[Sharocks]

It's an iron block so you can always try but I'd go for another S54. Will be cheaper as well. Sorry to see OP.

[Slideways]

Whoa, that is a lot of pre-det pitting on that piston. Sorry to see this OP. Best solution might be to find another S54.

[SteelGreyM]

Well guys here I am. The first truly f*cked engine on the new forum.

Earlier tonight I got my s54 head off to replace the head gasket... only to see a horrible sight. Im not sure how the hell this even happened but if I had to guess i'd say that a decent chunk of head gasket broke off and fell into the cylinder. Incredibly, the car ran like this but barely. The point of this post is to get some opinions on what the most logical decision here is. I am a college student so cost is unfortunately one of the biggest deciding factors.

At this point I think I would need a new set of pistons, and to rehone/ machine the cylinder. If thats even a thing. Believe it or not from the photos the scoring isn't super deep and my fingernail *barely* catches on it. My biggest concern is that there is a slight "chip" in the cylinder wall. I think this will be the thing that makes my engine toast. I have circled the chip in the photo. Also it looks like there is peppering all over the cylinder but in reality it's just a reflection.

There is corresponding damage on my head. Unbelievably, the valves came out without a scratch and it seems like they are all good. However, I dont know what im talking about to be honest and im just trying to go off of what little I know. I guess I just need to see if I can repair all damage on the head by only resurfacing less than .25mm right?

So heres my questions:

1) What in the hell do you think caused this damage?

2) Will re-honing my cylinder repair that "chip?" ( I think he answer is no but im not sure)

3) If I slightly bore out the cylinder to solve the chip damage will stock pistons + piston rings fit properly? (I guess it depends on how much I need bored out?)

4) Is the chip high enough in the cylinder by chance that it is above the piston rings and won't really affect things?

5) Is it even worth trying to salvage this block and having potential issues? Or should I just get a new block and pistons and call it a day?

6) If the valves and valves seats are okay my head is technically alright after being resurfaced right? Its not like the damaged bit is getting in contact with the pistons or anything.

Sorry if these are the dumbest questions...

I guess thats all for now. I'm sure I will have a million more questions later on once I narrow down my options. I really appreciate the advice and input...