[A_Wesker]

Hey guys, I have a G80 that would crank but not start so I took it to BMW, and they got it started. They told me they unseized the engine and now, it makes a knocking sound when the engine is on. The BMW I went to said I need a whole new motor. They said they do not do engine builds, so they need to replace it. I asked a buddy of mine who works at a BMW in Florida, he said that they do engine work over there. I showed him a video of the sound but he is unable to give a 100% diagnosis over video call. Someone offered to buy the car as is even knowing it needs a new motor. I would like to find out the fix and still keep the car though. If anyone can give any ideas from watching the video it would be greatly appreciated. Thank you.

https://youtube.com/shorts/obepldMLJ...mtTbvbP5ilUixR

[SwankPeRFection]

What year is it? Is it not under warranty? If the engine cranked, it wasn’t seized. Maybe something got lost in translation. A motor that doesn’t create compression will crank and not start, but there are a ton of other things that could keep it from starting. No spark, no fuel, etc. At minimum a compression check needs to be done to know for sure. I haven’t listened to your video, but if the knocking increases and decreases with RPM, then it’s rod knock… unless it’s something up top on the valvetrain.

Also, keep in mind that these engines have water based intercooler/heat exchangers, so if you pop a leak in that, you can suck in coolant and cause similar issues to hydrolocking, but that rare because I/C core leaks, it’s usually minor and leads to rough running or misfires before a much bigger failure.

[Ximian]

The fix is replacing the engine. Is this not covered under warranty?

The cost for the amount of time techs at the dealership would need to spend diagnosing and fixing each issue with the engine is comparable to the cost for replacing the engine, with a risk of another significant failure if something was missed during diagnostic stage.

[SwankPeRFection]

I watched the video and more importantly than the sound, where is that smoke coming from? Looks like possible exhaust leak or something else… oil residue or leak from valve covers.

Overall, we’re missing info on what possible codes were stored when they scanned it, etc. You got any more info you can add?

[Needsdecaf]

You need to give us a LOT more info.

Why wouldn't this be covered under warranty?
Mods?
What happened prior to "would not start"?
What do you mean "un-seized"?
What was done to "un-seize" it?
When you say BMW, are you referring to a dealer?
If a dealer, have you taken it to an independent shop?
Why are you calling a shop in FL if you are in NY?

Your post is super mysterious and missing way too much info for anyone to be helpful.

['Cane]

Originally Posted by Needsdecaf

You need to give us a LOT more info.

Why wouldn't this be covered under warranty?
Mods?
What happened prior to "would not start"?
What do you mean "un-seized"?
What was done to "un-seize" it?
When you say BMW, are you referring to a dealer?
If a dealer, have you taken it to an independent shop?
Why are you calling a shop in FL if you are in NY?

Your post is super mysterious and missing way too much info for anyone to be helpful.

Exactly, something (a lot) is missing here.

[Jax327]

A car with only 6k miles on it and needs a new engine....not covered under warranty??? Something doesn't add up here.

[ksa]

Only thing I can think of is perhaps it's modded extensively and that voided the warranty but ya post missing too much info. Hopefully the op will provide clarification soon.

[M4Lou]

New member - prolly troll until proven otherwise.

['Cane]

Originally Posted by M4Lou

New member - prolly troll until proven otherwise.

Not that new, member since December 2022.

[Gottagofast]

"Guys, I forgot to tell you that I put an ECU tune on it and took it to 800 BHP before the break in service and used launch control like 200 times in a row"

Yeah, warranty will cover you, bud.

[OUGrad05]

Originally Posted by Gottagofast

"Guys, I forgot to tell you that I put an ECU tune on it and took it to 800 BHP before the break in service and used launch control like 200 times in a row"

Yeah, warranty will cover you, bud.

Yeah something is missing here.