I noticed it yesterday and today. When accelerating from a stop a whistling kind of sound for two or three seconds. Almost sounds like a bearing. Today I noticed that it only does it when the AC is running. The noise is similar to brake pad squeal but higher pitched. Does this sound familiar to anybody?

 

Yes Yes I have this exact same sound on my e550 ...will teach me to fit up a Chinese branded AC pump

Id say the bearing on the AC unit are on their way out

 

But your AC works OK?

 

Air con still works fine but yes I get the noise when it's switched on

 

You have a 2007, yes? This may not apply to you, but two strange questions:

- does the noise sound like it's coming from behind the instrument cluster, sort of? Sounds like it's coming from a specific location in front of you?
- does it get stronger when you accelerate, or rev the engine? Especially accelerating between like 1500 and 2500 rpm?

And this "whine" is a single, very-high-pitched noise that kind of fades in and out, and ONLY occurs when the A/C is on? I had a noise like that which is a known problem, it's an A/C-related issue that is fixable at a dealer, costs about $200, and there are threads on it elsewhere here.

It drove me crazy, and the fix worked perfectly. But... I think it only occurred on 2010 and after model years. Not sure.

 

Mine is a 2010 and I think you are right. i just found a mention of a AC whistle type sound and a Jaguar bulletin on it: JTB00207. It's apparently not anything to worry about, just annoying. I'll get it taken care of next time I'm in for service.

 

Yep. Interesting story that I relayed elsewhere:
It's one of the few things may warranty would not pay on. Why? Because even though the TSB implies a defect in the original design... the fix, which requires the addition of an O-ring and spacer, involves parts not original to the car. Even though they're Jaguar parts, and the o-ring and spacer setup is built into newer cars. Oh well. (The problem, as I understand it, is there's a hard, right-angle bend that it's hard for the coolant to go around, and the fix addresses that. Something like that. Anyway, it works.)