Screeching sound when starting up

With Winter weather besetting my area of New York State already, I noticed a screeching sound on a couple of occasions when I took my '93 XJ6 out. Both times it was at or shortly after start-up, and then the screeching stopped. The temperature was in the mid to upper 30s, and I may have been using the heater / de-mister for the first time. When salt and snow don’t threaten my car, I plan to take it to the shop to have it looked at. My guess is an aged belt, but I don’t pride myself on having a large breadth of mechanical knowledge. That’s why I rely on you kind ladies and gentlemen. Thank you.

Not sure where the noise on your car is coming from and don’t know what model or year Jaguar you have but here’s one anecdotal story. A number of years ago my 1990 XJ40 had the viscus clutch for the fan seize up. This caused a heavy load on the drive belt when first starting up and when the RPM went over about 3000, the belt, even though properly tensioned, would slip, causing the squeal. New fan clutch solved the issue. You might post your year and model of Jaguar, and location, with your heading to assist others in solving your issue.

The OP’s car is a '93, so no viscous clutch, John.
I didn’t want to bring up the possibility of the harmonic balancer delaminating but that’s what the noise was on my '94. :expressionless:

Hopefully, just a slipping belt.

1 Like

Thank you John and Larry for your input. Knowledge is power, so knowing what I can prior to visiting the shop will be helpful, especially since I have yet to find a true Jaguar specialist nearby.

Get some white out and mark the harmonic balancer inner and outer areas with a straight line. This will indicate if the two parts are still in harmony (pun intended) :slight_smile:

1 Like

I must say that not having ever driven another XJ40 especially new or even low miles, I don’t have a benchmark to compare mine to. I say this because maybe more information that I can add to this personal conundrum is that I notice some vibration in the steering wheel, particularly at idle. In the back of my mind, it has always been, “This is not how a Jaguar would drive.” I am strongly leaning toward the harmonic balancer, and will try to do what you suggest, Robin, with the white out test. (Incidentally, thanks for the strimmer line suggestion regarding water pooling under the fuel filler door. I am sure a local garage would gladly have alieviated the weight of my wallet at the same time as addressing that problem.

Larry, if the harmonic balancer happens to be the issue in my situation, what kind of repair costs might I expect, based on your experience?

I’m not sure Philip, I did the job myself, following Joe’s youtube video - it isn’t a huge job and if it isn’t too annoying/slipping all the time, you can drive the car like that for quite a while.
Apart from the labour of getting it off, the main cost is the rebuilding of the balancer. Fortunately that service is offered by a couple of places and the turnaround is pretty quick.

I’ll look for the thread that has all the details and post it in a sec.

here you go, the blow by blow including my attempt at a Krazy glue repair …:face_with_head_bandage:

https://forums.jag-lovers.com/t/xj40-harmonic-balancer-failure/285796

Thanks for the link, Larry! The magic of youtube / Internet makes ownership more affordable and a greater connection with the car. I will probably have a shop do the work this time because I don’t want this car to be a guinea pig for my novice mechanical skills, but understanding the procedure will help build my courage to begin some DIY tasks I feel comfortable undertaking. Again, thanks so much for the guidance on this.

Yes indeed there is lots of experience here on the forum!

Did you check that the “screech” is the balancer for sure, using Robin’s white line tip? It’s a lot of work to go to if it’s just a slipping belt! :astonished:

I haven’t yet, but am looking to see how to do this the correct way. I watched a video online a couple of days ago, and need to see how to do this properly.

Just start towards the centre of the harmonic balancer and draw the line out to the extremity.

Of course, but first I need to find the harmonic balancer. As I mentioned, I have limited mechanical knowledge. It took the acquisition of a Jaguar to pique my innate mechanical inclinations.

This is what you are looking for;
https://images.app.goo.gl/KY42WXwMiLkK35vZ6
Its at the front of the engine behind the radiator.