Loud Turbo Whine When Stopping/switching Car Off

[Sunkist]

Hey Forced induction nuts!

My first turbo so forgive me for my noobness. Not even too sure if any of you can help.

Sinse I've have my Turbo Garret M24N highflowed to a Ball Bearing, ive noticed that after getting it back onto the car whenever I stop as a set of lights from acceleration, or turning of the car, the turbo has a loud whining sound as it slows to halt.

I just thought this may be a tiny leak just after the dump(hoping it is stil) letting the noise of the BB get through..

But having a mate listen to it.. reckons that it may not be getting enough oil and to open up the Banjo(something?)

Is it normal for Ball Bearings to be loud? or is it purely because of the leak right at the end of the dump-front pipe?

IF you need any specific info I may have missed ask me n I'll try and answer it as best I can.

EDIT: Ohhh and Thanks!

Edited January 11, 2011 by AaronNM35

[Duncan]

it is normal to hear some noise when you turn the car off, it can keep spinning for a second or 2. but I would not call it "loud". and you should not really be able to pick it from inside the cabin if the motor is running like at lights.

generally when they are stuffed though it turns up as a whining under load ie when you first hit max boost, so that may not be the problem.

i think you should be concerned....get a workshop to check it out. if it is failing the sooner you pull it apart, the less damage you will do to the turb and potentially motor.

[Sunkist]

it is normal to hear some noise when you turn the car off, it can keep spinning for a second or 2. but I would not call it "loud". and you should not really be able to pick it from inside the cabin if the motor is running like at lights.

generally when they are stuffed though it turns up as a whining under load ie when you first hit max boost, so that may not be the problem.

i think you should be concerned....get a workshop to check it out. if it is failing the sooner you pull it apart, the less damage you will do to the turb and potentially motor.

its not making any weird noises under load. Its runs at 14psi, and sound like the normal turbo once it come onto boost. I can only hear it in the cabin if all the windows are down, i forgot to mention sorry, so that could be why Im hearing it in the car, and its not so loud. If the windows are closed i cant hear it..and this is only when Im accelerating and then all of a sudden the lights go orange and I plant the brake, so the turbo would have been spinning as just off a higher rev.

Yeh I want to take it to the guy who did the Turbo, or should I try and cancel out the exhaust leak first? as i said it's leaking just after the dump about 5-6 inch from the Turbo, or would I rule this one out n just get the turbo checked.

(to get the turbo checked I have to drop the whole engine - $1500.00 + just for that - so Im trying to avoid)

Should I put up a sound clip tonight??

Edited January 11, 2011 by AaronNM35

[Beer Baron]

well I'm with duncan. yes ball bearing turbos will 'spin down' when you shut the engine off and you can hear them do it if your head is near the engine bay but I'm surprised you can hear it in car with the engine on even with windows down. I'd be a bit concerned too but don't know if I'd go so far to spend $1500 to get it checked. I would take it to the mechanic or turbo specialist and get them to listen to the noise. they should know by listening whether it's normal spin down noise or whether it's wheel touching housing noise, or bearing noise etc. either way get it to a mechanic.

[Sunkist]

well I'm with duncan. yes ball bearing turbos will 'spin down' when you shut the engine off and you can hear them do it if your head is near the engine bay but I'm surprised you can hear it in car with the engine on even with windows down. I'd be a bit concerned too but don't know if I'd go so far to spend $1500 to get it checked. I would take it to the mechanic or turbo specialist and get them to listen to the noise. they should know by listening whether it's normal spin down noise or whether it's wheel touching housing noise, or bearing noise etc. either way get it to a mechanic.

thanks mate. I called the turbo guy earlier today and he said they are generally loud(Im the only in Vic with a High flow BB[i think] which means im the first one so i cant compare it) especially with the very leaky gasket(wouldnt know why)

He's back on monday from holidays he said he would check it out then. its been in the car for 6 months now. it shouldve gone by now IMO if something were to be wrong.

Anyway Ill show him n let you guys know!

Thanks for the help people.

[Deano 1]

it also depends on how free flowing your exhaust is, i remember on my s13 track car with just a straight pipe for a exhaust you could here the BB of the turbo when it was just siting there at idle, same as my mates WRX with a decent sized exhaust you can here the turbo spining at idle, i wouldnt be worried.

[Sunkist]

it also depends on how free flowing your exhaust is, i remember on my s13 track car with just a straight pipe for a exhaust you could here the BB of the turbo when it was just siting there at idle, same as my mates WRX with a decent sized exhaust you can here the turbo spining at idle, i wouldnt be worried.

3.5 inch turbo back exhaust. one hi flow cat. and a couple of mufflers that dont do much.. lol.

the silencer is also taken of the intake "suction" pipe and blanked up.

[hypergear]

You normally hear a a spool down noise but a zz zz zz or abnormal high pitch sound would mean the bearing in it is on its way out. Also check the turbine wheel. Pretty much all GTxxBB high flowed RB25 turbos I've had for service / turbine housing upgrade had burnt turbine wheels.

[Sunkist]

well today i got the dump exhaust off..to try the exhaust gasket idea i thought off.. turns out there was maybe 1mm of the flange that wasnt leaking. when I pulled it off, it looks like the exhaust shop that did the exhaust did a dodgy, and shrunk the 3" to about 2.5" and put the stock flange back on. Scotty (another SAU'er and a f**kING GOOD fabricator) cut some of the exhaust off put it back to 3" with a new flange.. fixed.

Ok so made up a new gasket from Gasket material, with some gasket/exhaust seal. n put it back together..

it set.

Started the car.. i'de safely say about 50% of the turbo whine went away...sounds normal now..

still gonna take it to the turbo shop on monday to let him have a listen first..

Thanks people.

[Beer Baron]

sounds like you are on the right track. definitely still get it checked out. if the turbo guy has even half a clue he will be able to tell straight away if there is any abnormal noises there.

[Sunkist]

so a week ago i took the car to the turbo shop, and he said that the turbo was fine.

it is now a week later and this morning the turbo blew up.

Snapped shaft.

good thing for warranty.

You guys were right! thanks people.

[joeyjoejoejuniorshabadoo]

you can hear my turbo spin for around a minute after the engine is shut off

[ARTZ]

same here..

was it like that when u first got it though joe?

[Duncan]

so a week ago i took the car to the turbo shop, and he said that the turbo was fine.

it is now a week later and this morning the turbo blew up.

Snapped shaft.

good thing for warranty.

You guys were right! thanks people.

don' tell me...the guy that said it was fine is the same guy that should be warranting it

[joeyjoejoejuniorshabadoo]

same here..

was it like that when u first got it though joe?

ja

[Sunkist]

don' tell me...the guy that said it was fine is the same guy that should be warranting it

yeh he is warranting it. after he looked at it today he was shocked as, n hes lucky that there wasnt any eng damage. the compressor wheel was it pretty good nik apart from the fact it had seized.

he admitted his fault. is strange because ive never heard bad about his shop. but my turbo was the first turbo he converted to ball bearing. and hes the only guy in vic who said ill do it. he did another stagea. No Problems!

im just glad he is one of the few shops with after sale service.

cant wait for stage two sierra comp wheels.

[DVS JEZ]

Thats what i call a good shop. One that if they make a mistake (which everyone does) he admits to it and fixes it.

[Sunkist]

+1 on that, and not only rebuilds but upgrades and machines it to fit stage two sierra comp wheels

[Duncan]

Thats what i call a good shop. One that if they make a mistake (which everyone does) he admits to it and fixes it.

totally agree....big thumbs up to them

every workshop makes mistakes sometimes.