My M3 engine sound's like a diesel engine!!!! Help!

[nas320]

After i experienced the worst nightmare in my life Hydro locked engine!!! and a flooded car, i took my car to a garage for engine rebuild after we noticed a broken piston (number 1) and a bent rod.it took almost a month to get the car ready!!!!
when i start the engine and when it goes to almost idle power at around 600rpm i noticed the engine sound's not like before!!! it sounds like a Diesel engine!!!!!
Pls any help to solve this problem!!!!!!

[Eugene-TAIWAN]

I would suggest to find a bmw dealer and have a look

[elm3]

Originally Posted by nas320

After i experienced the worst nightmare in my life Hydro locked engine!!! and a flooded car, i took my car to a garage for engine rebuild after we noticed a broken piston (number 1) and a bent rod.it took almost a month to get the car ready!!!!
when i start the engine and when it goes to almost idle power at around 600rpm i noticed the engine sound's not like before!!! it sounds like a Diesel engine!!!!!
Pls any help to solve this problem!!!!!!

Sounds like the idle is too low at 600rpm, it should be more like 750rpm, if I'm not mistaken. Low RPMs will make your engine sound rough. So it could be your RPMs. Try to take it to the dealer and see if the can adjust it.

[FStop7]

Who did the rebuild? Was it under warranty?

[RevFreak14]

Originally Posted by elm3

Sounds like the idle is too low at 600rpm, it should be more like 750rpm, if I'm not mistaken. Low RPMs will make your engine sound rough. So it could be your RPMs. Try to take it to the dealer and see if the can adjust it.

+1, 600 RPM is too low IMO. Should be around 750-800 at idle. Just bite the bullet and take it to the dealer. They'll be able to tell you for sure.

[nas320]

Originally Posted by FStop7

Who did the rebuild? Was it under warranty?

i did a rebuild in a friend garage! as here in UAE, AGMC witch represent BMW they don't do engine rebuild??? they said even you have to change all ur engine charging me almost 40000 USD!!!!

[nas320]

same friends advised me to do valve adjustment??? or to change the spark-plugs??? is that can help?THX.

[nas320]

Originally Posted by RevFreak14

+1, 600 RPM is too low IMO. Should be around 750-800 at idle. Just bite the bullet and take it to the dealer. They'll be able to tell you for sure.

thanks for the advise!!!

[JCtx]

Originally Posted by RevFreak14

600 RPM is too low IMO. Should be around 750-800 at idle.

ALL M3s I've driven (4) idle around 550 in N. And a little higher with clutch depressed. Yes, that's pretty low to me too (thank the EPA ), but if engine is making noises now, it's something else.

By doing an amateur rebuild on this engine you probably killed 1/2 the value on your car. You didn't answer the question what the heck were you doing that you weren't covered by your insurance .

[nas320]

Originally Posted by elp_jc

ALL M3s I've driven (4) idle around 550 in N. And a little higher with clutch depressed. Yes, that's pretty low to me too (thank the EPA ), but if engine is making noises now, it's something else.

By doing an amateur rebuild on this engine you probably killed 1/2 the value on your car. You didn't answer the question what the heck were you doing that you weren't covered by your insurance .

Insurance in uae does not cover natural disaster!
and the engine is rebuild with a well known garage!
Driving the car is perfect no power loss and all the Systems are ok! Except that anoying diesel sound at idle power!

[MrHarris]

Originally Posted by RevFreak14

+1, 600 RPM is too low IMO. Should be around 750-800 at idle. Just bite the bullet and take it to the dealer. They'll be able to tell you for sure.

My car idles at 600 when it's completely warmed up. I think that's normal. It definitely shouldn't sound like a diesel engine. Get that checked by someone reputable.

[nas320]

Originally Posted by MrHarris

My car idles at 600 when it's completely warmed up. I think that's normal. It definitely shouldn't sound like a diesel engine. Get that checked by someone reputable.

600 rpm that's the normal idle power after eng warm up!!!! totally agree !!!!
in cold start rpm will jump to 1000, 1200 rpm then will stabilize at around 600 rpm.

but i really don't wich to anyone of u guys to experience what i did!!!! it's really a nightmare...... i don't wanna go out of topics but if there is any advise u r the most welcome!!!!thx!

[gemini330zhp]

I wonder if you can put a Chevy Small Block in the M3??? Cheaper more power and new. I know this sucks. Seems like you need to find a good engine builder or try new things. No matter what its going to cost you. What did your insurance company say??? This should have been covered under you insurance policy????

[FStop7]

I'm concerned the diesel sound you describe is rod knock.

If you put the car in neutral and slowly press the gas pedal, does the knocking sound speed up as the RPMs increase?

[JCtx]

Originally Posted by nas320

Insurance in uae does not cover natural disaster!

Sorry for what you're going thru, but you need to be honest: Driving thru enough water to hydrolock an engine is not a natural disaster; it's driver error. However, you should be covered regardless. Who's going to finance a car if it can't be insured against flooding related damage? I bet there's more to the story, but obviously you don't want to talk about it.

Anyway, that 'diesel' sound is bad news. It can be anything from rods to improperly installed hydraulic tappets, leaving too much valve clearance. You need to take it back. My question to them would be: What the hell did you change, and what parts did you use? Without being honest what's going on, don't expect much useful help. Good luck man.

[Tio///M]

Word to the post above

[BPMSport]

Could be a number of things that would cause that. 600 idle is not abnormal.

Are you positive they installed the cams and vanos units correctly?

[vm]

I dont' know what you mean that is sounds like a diesel but check the exhaust manifolds for leaks at the head because this can cause unusual engine sounds.