First let me say i'm not sure wether it is an issue or not.

in fact i noticed recently an hissing fan noice coming from the engine compartment of my 2003 4.2 xk8.

it only appears when the engine has reached operating temperature and it increases when engine is reved up, regardless the electrical fans are operating or not. To exclude the a/c compressor i pulled the clutch relay, no changes so far.

i appreciate every opinion,

thanks, fritz

 

Fritz,

Can you identify whether it's coming from the engine or from the auxilliary components?

If it's engine then the primary/secondary chains are a possibility although problems are rare in this area on the 4.2 litre.

If it's definitely not coming from the engine itself then eliminate the auxilliary components one by one. You've already investigated the AC Compressor so move on to Water Pump bearing, Alternator bearing or Drive Belt tensioner.

Posting a video or audio clip might help.

Graham

 

Hi Graham,

don´t know exactly where it comes from, i assume its coming from the engine itself because if the engine is cold there is no noise. i think if it were caused by an auxillary item it should hearable on cold engine too.

"noise" is actually kind of exaggerated, sounds just like a rev depending fan. the annoying thing is, there is no rev depending fan.

i´ll try to post a clip the coming days.

thanks so far,

fritz