Whistling noise at dashboard area
 

Hi all

I hear a whistling noise that seems to come from my XK 2008 dashboard area.
It changes and follows engine revs. It's present without A/C and radio/CD. Never stops while engine is on.
Attached a short audio file over several locations around the dash

Any idea what may be the source ?

Thanks

The engine air intake has a hose that pipes intake noise to the passenger compartment. Perhaps this is the source of the noise that you have noticed?

I don't know...
where is it ?

Can you hear it in your XK as a whistle ?

1. Find the engine air intake black plastic tube which runs along the front of the engine. Note that it has a rubber hose which connects to the engine compartment firewall. That hose transmits sound.
2. See if you can hear this whistling sound while you are standing outside the car, the hood is open and the engine is running. If you can hear it, try to localize the source of the sound. Maybe you have a slight leak in the air intake which allows the whistling to develop.
3. Disconnect the rubber hose mentioned in #1 above and see if that affects the whistle as heard in the passenger compartment.

I do not hear a whistle sound in my 2007 XK.

Thank you Patrick for the detailed explanation
Do you mean the hose coming out of the red arrow in the attached picture?
https://cimg6.ibsrv.net/gimg/www.jag...68a447574b.jpg

It's not at 1200 rpm. It is continously at all rpm's even with A/C off

Well Patrick, yes the whistle is very similar to what I hear just near the air intake hoses.
I don't know if there is a leak and how to find it...???

If can't find the source of the noise/leak, is it ok if I disconnect the hose going in the cabin?

Thanks
Danny

The hose that leads from the intake air box/tube to the firewall is only there to provide intake sound, so the you get a "sportier" sound in the cabin. I found it anoying (eventhough mine is a vert) and pulled the hose off, pushed a wine cork in it (being careful to not shove it in too far to easily pull back off) then reassembled the hose to the intake air box. The result was a much quieter cabin with the top up and might stop the sound you are experiencing. If I'm off base on what you are seeing please excuse my post.
If you disconnect it at the air box you have to cap off port so as not to allow unfiltered air into the intake stream.

Did you push the cork into the hose or into the air box ?

I made sure the cork was clean, ie. not flaking little pieces off, slid it into the airbox port then reattached the hose. I have a hose clamp tool that allows the clamps to not get damaged so that made the job a breeze but, as you probably know, pliers will do the trick too. I also made sure the cork only entered the port part way so that it was easy to remove if I wanted and also did not enter the air stream within the air box. The cork was a tight fit so I was confident it wouldn't work it's way forward into the box.
Hope that helps.

Sure, thanks

Thus the expression ' Put a cork in it will ya'

Solved
 

It was the alternator. There was no charge warning or so but at least on of the diodes was shot. Somehow the whining resonated into the cabin as it was under the dash.

Hope it will help someone