I have been hearing a ticking noise from just behind my air filter. It has got worse after fitting a K&N cone, sounds like something electrical like a relay opening and closing any ideas? and what is the cylinder behind the airfilter?.(uk turbo 98)

 

Hiya, mounted on the OS suspension turret is a selection of relays etc. the tall cylindrical one [ I'm being deliberately un technical here ] is mounted on two rubber spacers. they go hard and rattle like mad. IF it's them undo the screws take out the spacer tube and re-tighten to squash the rubber spacers and then fit a locknut to keep the whole job tight. It's a good cure if that's the problem. Good luck David API Engines

 

boost solenoid valve. i have a k+n aswell