Sti Version 4 Type R

Hi needin some answers to what this could be - just really noticed tonight as I decided to take things easy and drive home very slow and no music - so whats happenin - basically when I drive the car and take the revs to about 3 - 3/5 thousand ( I am just touching the throttle here and giving it no pressure so the revs rise to this mark but the turbo aint really in, if that makes sense ) so at 2,750 - 3,000 rpm its makes a very very weird low pitched kinda grinding noise coming from the turbo ( I think ) it dosnt sound like grinding like normall but thats the best way a can explain. - after 3,250 it dissapears.....

Very worried - its due its 1,000 mile service in a few days after its just had a full rebuild.

Sti Version 4 Type R

23 views and no one able to help out - am gettin worried as a have just forked out major cash top fix this and am extreme paranoid -

Pedro_79

Is it a metallic flapping kinda noise? If so, it's most likely the turbo heatshield...

Dark Blue Mark

Probably as above. Pop the lid and use the throttle body arm to rev the engine, you should be able to trace the noise after a while...

MB

Sti Version 4 Type R

that was ma 1st thoughts - they all seem to be solid - the noise sounds like its internal - like a groaning from the turbo just before it boosts - its almost like a power steering belt whining but a think its form the engine? am sure its starting to get worse

Dark Blue Mark

Turbo bearings are your next bet if you're sure its from there.

MB

mannyfold

sorry to jump in but if turbo bearings are gone how expensive is it to sort out? are parts the same on jdm tdo4 as uk? and if you don't sort it quick are you gonna kill the turbo?

i only ask since i think mine are going.

cheers

Dark Blue Mark

Its not a problem you want to leave, as the turbo / compressor may decide to self destruct and you are then in the lap of the gods as to how much of the blades ends up inside your engine

Not sure on turbo interchagability, but somewhere like APi breakers will see you right. Standard refurb turbo's aren't too pricey.

MB

mannyfold

would failing turbo bearings be audible when at a stand still? will it be after you relase the gas pedal or whilst revving?

Dark Blue Mark

Only when spinning, you can get it to boost on the driveway using the throttle body. Will spin for a while after so you can hear it run down. Note - roller bearing types do whine a bit more than others. Not sure what you have?

MB

Engineer@Uni

I can't help wondering why the noise seems to go away when past 3500. I am tempted to think that it's something irrelevant thats just hitting it's natural frequency and vibrating. That would explain why you get it at such a small band of revs. If it is the turbo, it should do it when spooling up and down, irrespective of the engine's revs. In fact, the turbo's speed is pretty much close to irrelevant as far as engne revs are concerned.
frictional losses are proportional to the cube of the speed, so if a non-spooling turbo (as in, not boosting) is running at a few hundred RPM and then the bearings start to grind just as it's getting on boost (say, 10-20k rpm) then surely it would blow appart on full boost at 120-130k rpm which isn't particularly fast for a turbo. I'd second the idea that it's the heat shield or possibly some flapping bit of plastic/sheet metal. This looks too suspicious to be anything other than a little resonation.

APIDavid

iTrader: (4)

I'd go for a rattly turbo heatshield or possibly a fractured turbo up pipe. Especially as the engine has been disturbed quite recently.

VF [STi ] turbos usually whine a bit from the roller bearings but don't usually grind. I don't think it's much to be bothered about.

How about taking it back where the rebuild was done and getting them to look-see.??

David APi Engines / APi Impreza

Dark Blue Mark

Agreed a heatshield is more likely -

Engineer at uni, not sure what the critical speed of these turbo's is, but as the turbo goes through this it would be one of the most likely points for it to blow, or at full speed as you say. (Critical speeds much less of an issue on somehting this size however)

Note there are heatshields on the underside of the turbo and on the manifold. I would repeat that you should be able to hear where its coming from if you put your ear on it and rev the car.

MB

STIPPP

I have just posted a new topic on this, as i have the smae thing occurring and at the same RPM range. It seems to be doing it between 2K to 3K and then the noise disappears. I have a new 2005 STI with PPP, and used to have a standard WRX with PPP and that never did it. I spoke to my dealer and they want me to take them out in it to see if they can see what the problem is. If you are driving hard, you don't even notice it, but only when you are chilling out in the car and under very slow acceleration. Glad that there are two of us that are paranoid about it!! Surely there are more out there that have had the problem, if so let us know! I shall have a look under the bonnet properly when i give it a spring clean at the weekend.

chriswrx94

shouldnt be anything major with the turbo at that miledge etc, id put it down to a heat shield somewhere, possible front pipe etc, they tend to like to resonate at a certain idle.