Recently my S40 has developed a strange whistling noise when accelerating. It is loudest when first driven in the morning. It gets louder as the revs increase and seems to be coming from the front of the engine.

It does it when standing in "N" so it's not a wind thing... any ideas?

 

Check all the rubber hoses from the intercooler to the turbo for holes and cracks.

 

Hi there.

Could it be a loose pipe clip or a hole in a pipe? Gap/hole might seal as things expand on warmed-up engine. Is the air filter box sealed properly & air filter seated as it should be? Seals around throttle body? Process of elimination.

Normally I would suspect a leak in a turbo hose, but not sure whether yours is normally aspirated or turbocharged.

Other than this, could it be a belt noise? From your description, noise doesn't sound mechanical.

Good luck tracking it down Daniel.

BB

 

Thanks, i'll have a good poke around in there and see if anything looks lose. It's the 2L NA, so not a turbo issue.