I have noticed a slight groan, for half a second or so, when the turbos first start to boost!

 

Any ideas?

Is it more like a 'honk'? If so this is normal. If not - then I've no idea!

If you have removed the std air box you will hear the recirculation valves (like blow off valves) when you back off the turbos. Is more of a honk though mine sound like a train siren and last for 3 or 4 seconds. If you have std airbox you shouldn't hear it. Then it would be something else. Are u sure its turbos and not something else groaning as the power kicks in?

It would (should) be the wastegate actuator you hear when you back off the turbos as you describe it, a standard fitment recirc valve shouldnt make any noise.

If its a bit like a hoot when spooling up, the recirc valve could be leaking, but it does just sound like a normal kind of a sound.

 

[This message has been edited by Ay3388 (edited 18-12-2001).]

Also check the intake for quality of filter and/or any cracks in piping, cos it also sounds like it could be taking air in through a small crack in the piping.

But i could be talking crap.