I notice this in the cold weather nad it goes away after a minute or two of driving. The squeeling SEEMS to be coming from the front/left of the engine bay and only at low speeds when the car is first getting warmed up.

I've also noticed that even after as long as a 90-mile drive, my car's temperature never moved from Cold more than a negligible amount and only seems to do that when I'm driving heavy-footed.

Related most likely?

Thanks!

 

Hi Dan,
Just shooting the dark here, but sounds like a loose or worn belt for the squealing and the thermostat being stuck wide open for engine not getting warm.
Either way they are both easy to check.

 

Thanks. I should have mentioned that two belts were replaced recently because I thought the squeal was from them. One was worn pretty bad anyhow so I asked them to just replace both in hopes that this covered it.

How would I check the thermostat? I read somewhere that the water pump could squeal like this? I'm no car guy but am learning. I assume the thermostat and water pump work somewhat hand-in-hand?

I may be adding too much to this but I'm also noticing some voltage drops from time to time when cold only....I'm thinking maybe that's the new belts needing tightening already (brand new battery installed as well as it tested bad two weeks ago).

Just trying to keep on top of the issues and understand this car cause I love it.

 

Hi Dan,
With the voltage drop, it could just be the cold weather.
How often do you drive the car and how far, and do you lock the car at night?
Locking the car and setting the alarm effectively puts the car to sleep and reduces the drain on the battery. Keep the battery fully charged and you should then be ok.

As you suggest, it may be the water pump at fault. Look in the how to videos at the top of the forum page for removal and replacement.

The thermostat you can remove quite easily. Check the general condition, see if it is already open. If not, put it in a pan of water with a temperature sensor and heat it up, see if it then opens.

However, from what you have said I would probably change both especially with a car of this age.

Hope this helps a little,

 

Not unsual for needs belts to stretch a bit need re-tensioning after a short time.

Yes, a water pump or alternator can make a squeel sound due to an internal problem.

The next possibility...perhaps more likely than a water pump problem.... is that your harmonic balancer is delaminating. As these cars age it seems to be cropping up more and more often:

https://www.jaguarforums.com/forum/x...995-xjr-84032/

Your voltage drop could be related to balancer delam as well.

Your thermostat is almost certainly stuck open, as previously suggested. They're known to fail "open" on these cars.

Cheers
DD

 

If you are going to change the thermostat yourself, make sure you cover the belts so that you do not get coolant on them, they will squeel if they get wet with coolant. The first thing I did with my XJ6 was change the thermostat because it was not getting up to temp.
Try tightening the alternator belt and see if that stops the noise, like Doug said. Hopefully, you do not have a balancer delaminating.

 

Dan I hope its not your harmonic balancer the one in my xj40 went at 175,000k,s yet my xjr has 240,000 k,s and is all right so far (hope I just didn't jinx myself)

 

Sound like alternator and/or alternator belt. And thermostat failed open. Just sorted those two issues myself.

95 XJ6

 

I'm having the same issues as well. How do I find and remove the thermostat? Also I notice in my car that on very cold mornings (which are rare here) it takes quite a while for the heater to warm up the interior. Would that be caused by a thermostat which had failed while open?

Thanks,
Aaron

 

If the temp gauge needle gets to the half way mark within 10 min. and you still do not have hot air from the heater, it could be that the heater core needs flushing or the heater pump is not working. But chances are it's the thermostat, the don't hold up forever.
The thermostat cover is at the end of the hose that comes from the top of the radiator and has two bolts securing it to the front of the cylinder head. It is a good idea to get a workshop manual CD which has parts diagrams and torque values as well as instructions for doing many repairs. I got mine on ebay for $15 + shipping. The parts diagrams are handy for identifying those mysterious things attached to the engine. While your at it, how does that radiator hose look? Is it bulging a little? A cheap replacement.

 

One additional comment: Look carefully how thermostat is oriented before you remove it. The little jiggle valve should be at the top.

 

Thanks for the info! I was just researching it and found the same info. Also learned that when too much coolant is getting through it can negatively affect your mpg.

I'll have to look at the hose and let you know.

Regarding the CD manual, I had completely forgotten that the guy I bought my Jag from gave me copies with the car. (I've had her less than a year.) I'll have to check them out.

 

I've had the harmonic balancer let go on both the Excursion and a 3.0L S-Type. I'd call it more of a chirp than a squeal - both sounded the same...a high=pitched chirping on cold start. THere's a test with painting white dots - maybe in the link Doug posted. +1 on stuck thermostat, they are popular on this model. Be careful not to break an ear off the elbow.