... seems to be only on cold start up and lasts 5-10mins.

Sounds like its coming from maybes the belt pulleys??

Its a '97 WRX, belts done 12 month ago by subaru and full engine rebuild (forged) done about 8 month ago, last serviced about 3-4month ago.

Any ideas?

 

Slack aircon and/or alternator belts?

 

Yeah it sounds like a belt.

 

I had a similar noise coming from the crank pulley. Very squeeky noise. It went away after i sprayed some WD40 whilst it is was spinning.

 

Aye, WD40 is the next move, its quite rare it happens and isnt even that loud, its just canny annoying with windows down.

Would the air con belt spin if the air con wasnt turned on? Something i've never thought about... just trying to narrow down which belt it may be

 

AFAIK, the compressor doesn't run when the aircon button is "OFF" or no power to it.

So make sure button is off, then start car again, etc. to rule out/in the aircon belt...

 

Ok, cheers ya'll