Hey all, couldn't quite find a similar post to what I'm experiencing in my Jag, so I thought I'd make a new thread about it. Also, I posted this in the wrong forum, so I am making another post here, sorry for the double post.

My Jag is the 1996 4.0L XJ6 - VanDen Plas Edition

Here goes: I leave to go to work at 3:40 AM, every time I start the my car, about a second later, a terrible squealing starts. I step on the gas, it goes away. It is RPM dependent, and the longer the car is on, the lower the rpms have to be for the squealing to happen. The noise is only there at below 40mph, anywhere above that and it doesn't happen.

I did replace the drive belts a few months ago because I thought they were the culprit. Apparently they weren't, however one was cracked a bit and so it needed replacing anyways. I took it in to Rizzoli's twice now and left it overnight so that they could cold-start it in the morning, however on both occasions it did not make that noise. Very frustrating.

If anyone can help me out with this, it would be most appreciated. A beautiful car should not sound like this.

-Zach

 

Sometimes new belts stretch a bit and need to be re-tensioned.

Although a rattle-grind noise is a more common symptom, sometimes the belt driven devices themselves---alternator, a/c compressor, water pump---can squeek, screech, or squawk, usually signaling impending bearing failure. Same applies to the belt idler pulleys

One trick that may help isolate the problem is increasing the electrical load by turning on your lights, rear windown defogger, heated seats etc. If the noises suddenly worsens it's probably the alternator.

Cheers
DD

 

So I took it in to the shop again today and they were able to hear the squeal and it turned out that the water pump's bearings were loose (i think) so I need to get a new water pump, but they want to charge a LOT so i'm gonna look for some DIY manuals and change it out myself.

 

The belt tensioner pulleys can also squeak as the grease ages & the bearings run dry. I had this problem on my previous 1995 Daimler Double Six & have it now on my 2001 XJR.

 

I have a 1996 XJ12 that would has a similar problem. It turns out the harmonic balancer pulley that holds the belt for the alternator has come loose from the harmonic balancer. I mention this because it is not obvious. The pulleys still spin, it is just the alternator doesn't get full rpms and at times it squeeks, especially after a cold start.