I recently purchased a 1998 XJ8 L. I've noticed a soft whistle noise when I accelerate with the AC on. This occurs only when the AC is on, and the it sounds like it is coming from inside the cabin. Could this possible just a simple crack in a vacuum hose?

 

I've got the same problem, and also assumed it's a vacuum leak which is harmless (albeit less efficient) until it sets off an error code (mine hasn't)

Fyi, make sure your radio is off - I also get some whiny radio feedback from the transmission, lol

 

I've noticed a similar issue. Soft whine when AC is on, increases with revs, seems to be more pronounced soon after starting the car. Noticeable inside the cabin, I can even feel it slightly in body-connected parts like the parking lever. Outside the car I can't hear anything, and even when I put a stethoscope on the AC compressor I couldn't hear any whining at all.

I'm at a loss, but I haven't had a chance to look at AC system diagrams yet.

 

VDPNYC, I haven't had any radio 'interference' or feed back and the 'whistle' noise occurs with or without the radio on. As with NILANIUM I haven't had a chance to look at the diagrams yet either to determine where there are any vacuum lines in the cabin.

 

Why no one reads the TSBs is still a mystery. Jaguar answered this question 15 years ago.

bob

 

Thanks MOTORCARMAN for attaching the TSB! Where can one find any of the other TSBs? --I'm new to Jaguar.

 

Wow that is a lot of repair work to fix a noise, lol. The A/C works, so I'm leaving it alone...

 

Agreed on the effort to fix being too much to do anything about it for now. Does the system work the same for supercharged x308's? The tsb says it is only on NA cars.

 

It does not matter how much work it is when we had to repair the car during factory warranty. We just repaired it and sent the customer on their way!!

Customer pay is another story. The repair bill was something to consider.

bob