Odd noise coming from Engine Bay
 

Hi ,would really like some ideas with this problem .I have a RHD Uk spec 1992 944 S2 and have developed a strange noise from the front of the car somewhere .It only happens when driving soI can't lift the bonnet and listen for it .The only way to really describe this noise is if you can imagine someone playing a trombone or an oboe but only holding one deep bass note, strange I know but it's definetly not a rattling or grinding noise .Never happens when the car is cold, only when warmed up.

If you drive the car gently it doesn't seem tohappen for ages(but eventually does) but the minute you give it a bit ofaccelerationthe noiseappearsat the exact point when you've lifted the clutch and engaged a lower gear. as soon as you depress the throttle that's when it happens. The aforementioned noise will continue and sometimes will slowly die off or you can get rid of it by depressing the clutch but the minute you let the pedal up, it's back. The noise will continue until you get to about 5 miles an hour then disappears . You can feel slight vibration through the steering wheeland pedals. I disconnected the steering pump to find the noise was still occuring but could feel nothing through the wheel .

Also disconnected the alternator but made no difference.It sounds as if it is coming from directly in line with the steering wheel out in front somewhere but my wife insists it's coming from the clutch area. Definetly sounds like it's directly in front when you're in the drivers seat My clutch release bearing does make a fairly noticeable noise when the engine is idling in neutral, could it be connected? I also checked the chain and tensioner and all seems well . Another point worth mentioning is that when the car is slowing down without the noise present, I can hear a whirring noise which gets quieter as the engine slows which is definetly coming from the clutch area . The clutch was replaced 40,000 miles ago by a decent garage so should've been fitted ok but I would've thought it a bit premature to get release bearing noise. Again, could this point to something more sinister?

Hope this all makes sense as it's really hard to describe

Any help would be appreciated and many thanks in advance.