Very Loud Turbo Whine

[3LGODZILA]

sorry for the long read but i tryed to add as much info as possible

car is a series 2 r33 with the infamous nylon compressor wheel

mods = the usual for 200kw with standard turbo (3inch exhaust bellmouth dump decat pipe, FMIC, MBC running 9psi at the time, pod filter, metal intake pipe)

car has been running fine ever since last nite, gave it shit in second gear as i changed into 3rd around redline i head a loud WUUUUUUUUUUUR noise that sounded like a cop siren. and now its constantly making the noise very slightly at idle and as soon as i give it a bit of throttle even when my boost gauge is reading in vaccum. i gave it about 1/3 throttle and it made 2psi but i didnt wanna try see if it makes any more incase the something in the turbo wasnt right and it fed my engine peices. the car did feel slugish on the drive home

soooo immediately i thought my turbo shat itsself so ive pulled most of the piping off everything seems fine. i personaly havnt felt the shaft play in any turbo wether it be brand new or rooted so i duno if mine is acceptable or not but ill try to explain it, i can pull the impeller shaft in and out but only VERY slightly maybe around 1mm? and if i pull the shaft out as much as i can i can very slightly move it up and down maybe around half a mm. i had a look with a torch and the impeller wheel seems fine its all intact spins freely and there no chips on the edges.

what should i look for now is it worth pulling the dump off to see the condition of the exhaust wheel or is it only the compressor wheel that gives way?

and also i checked all my cooler piping to check for any leaks all clamps are tight and seem alrite silicone joiners are good.

is it possilble for the FMIC to shit itself sumhow with a small leak or something, i did buy it second hand about 6 months ago no major dents and i have never hit or scraped it on anything

if its something like a intake manifold gasket how do i check if its rooted, anyway other then pulling the whole thing off???

oh yeh 1 thing i forgot to add, while the engine was running i put a screwdriver to my ear and reved it slightly to get the noise to come on, when i held it on the metal intake pipe comming off the turbo the noise was definately there, i then put it to the intake manifold and it wasnt there. so im leaning towards the turbo but wat could it be the bearings or seals??? car isnt blowing smoke btw

[StealthX]

is it worth pulling the dump off to see the condition of the exhaust wheel

yes! this is the first thing i would do...

is it possilble for the FMIC to shit itself sumhow with a small leak or something,

VERY unlikely...

in and out shaft play is the one thats not tolerable, im think that even a mm or so, isnt too good at all.

having said that, i think the condition of your exhaust wheel is the key here... have a look at that...

[DuFFR32]

My car is doing this atm but not as bad a case as yours sounds...

Its a hot-side leak i think most probably a gasket between turbo to manifold or turbo to dump or small hole in exhaust dump

In mine i found a little hole in the dump pipe which im sure is causing the sound but im going to take the turbo off and check it and make sure its all sealed properly

[Luciano]

my bet is a leaking exhaust manifold gasket, broken studs etc. quite common in rb25det's

i had a few broken studs and a little chunk of gasket missing, causing a very high pitched squeal under boost. very annoying

[3LGODZILA]

had a mate that knows his shit come over and have a look, he recons must be the bearings or internals coz u can feel it vibrate as the noise comes on wen i rev the engine

so im in the process of pulling the turbo off atm, just got that last oil drain that goes to the sump to get off hoping my 1 week old motul wont go to waste ahhahahah

havnt got the car jacked up atm and its dark :S i can feel 2 bolts under the turbo are these the ones to take off the oil drain to avoid losing much oil??

oh yeh dump pipe gasket and the gasket between the turbo and mani were both good, no snapped bolts/studs although all the turbo bolts came off fairly easily but i still had the crack them with a spanner so they weren't finger tight or anything

Edited February 15, 2010 by jimmys-33T