My 07 XK X150 4.2 NA has a very pronounced squeal just after starting the engine. It goes away after 30-60 seconds. Alternator is new and all the pulleys, tensioners, water pump, drive belt, auxiliary coolant pump have been recently replaced. I've run out off ideas what is causing the noise. I'm hoping y'all might have an idea.

Details:
Noise occurs when engine is cold. It starts ~5 seconds after the engine starts. It goes away after ~60 seconds.
Higher RPMs don't change the sound.
Noise sounds like it's on the right hand side near the radiator/alternator.
Car is RHD.
If you turn the engine off before the squeal goes away, the noise continues for a second or two, sounding like something spinning down.
Pulling relay #3 under dash before starting engine has no noise. When car is running and plug in relay #3, noise occurs as above. So I assume the problem is on that circuit.
Air condition system was empty of gas.

What's been tried:
Belt dressing
Replacing tension, idler pully, water pump, hoses, auxillary coolant pump(attached to radiator).
Alternator was replaced almost 1 year ago. Noise was there before alternator was replaced.

Thanks much for any help or ideas of what to look at.

A

 

Belt dressings are never the fix. To pinpoint an issue, a stethoscope is your friend.
But without being there, I'd bet $1 that its a belt tensioner, the generator spindle, or something similar.

 

I use a flexible tube as a stethoscope. My go-to is a vacuum cleaner tube. Works everytime, just move it around and listen.
Rick

 

And belt was not installed inside out?

 

on my 1994 xjs, had this and had to replace the hydraulic damper. "2007-2009 Jaguar XK Vibration Damper AJ811116"

 

From your description that sounds like the secondary air injection pump.

 

I agree!
WJ

 

Funny you should say that. The one detail I forgot to add was on my way home, I got a fault for the Secondary Air Injection Pump. I'd never seen that before hand.

How deep in the engine bay is it located? The radiator, fans, etc are out right now.

And is there only one? There was mention of one of the banks was running lean. is there one for each bank?

Greatly appreciate your insight.

 

Did you look at the Workshop manual?

Where do I send the $1?

 

remove right side front wheel well liner and you'll have acess or remove r headlight, same scenario.
wj