Squawk noise on cold start 1995 XJR
 

Help my thought process along, please.

For several weeks I've been getting a squeek-squawk noise on cold starts. Most anyone would hear the noise and say "Loose belt". It's that type of sound. It is very easily aggravated by increasing electrical load. What begins as a fairly mild squeek turns into a hellacious squawking racket when lights, rear window heater, seat heaters, etc are turned on. Turning them on/off in steps increases/reduces the racket in steps.

After 10-30 seconds the noise goes away and will not reappear until the next cold start.

1) I tightend a slightly loose alternator belt. No change.

2) I observed a leaking water pump and replaced it. No change. (I was hoping the two might be related....coolant migrating onto the belt....no joy)

3) New alternator belt installed on GP (when w/pump was replaced) as I was thinking the coolant may have permeated the belt.

4) Other two belts are new-ish, no cracks or visible wear, properly tensioned. All pulleys clean and aligned.

5) Using stethoscope on all engine driven accesories and pullies I am unable to locate the noise. As luck would have it, the noise was very short duration whenever I tried listening for it and longer duration whenever I wasn't ready with my stethoscope :-)

6) A bit desperate and knowing that, although a bit unusual, alternators can emit odd noises from their innards, I replaced it. No change.

7) Yesterday the noise lasted long enough ....probably a full 60 seconds...to check all engine driven accessories and pulleys with the stethoscope. All quiet, unable to isolate noise.

What next? Ideas? Thoughts?

I am wondering about the harmonic balancer. I'm assuming (a bit ashamed that I don't know) it's a typical two piece bonded affair.....and perhaps the bond is gone? Looks like I'd have to remove the fans and then the crank pulley for a decent inspection.

Any history of balancer bonding problems on these cars?

Cheers
DD

Doug,

Balancer would be my bet. Had one go South on the Excursion and again on the 2003 S-Type. So far, so good after 120k mi. on my X300. But you are describing the exact symptoms. A chirp or squeal? Mine didn't seem to be affected by elec. load on either vehicle. Also, each made the chirp on startup for 6 mo. or better before it started throwing the belt (Exc) or shredding the belt (3.0L S type)

Ide bet on the balancer too. I changed mine when it went bad @125k

What was the problem/symptom with yours? Did you install new or have yours re-bonded or?

Looks like a new one is +/- $1000. Ouch.

If it's a matter of the bonding coming apart I'll send mine to Damper Doctor or similar.

Cheers
DD

Had the Exc renewed at/by the local Ford Dlr - back in the days of not having a spare, so didn't have the luxury of fixing the down ones at my own pace. Anyway, they fitted a new one and I never saw the old one again - think it was $400-600 parts and labor.

I actually never found the S-type...but after changing tensioner, then water pump....then a fair bit later....the drive belt in an effort to chase the squeal away - it started shredding the new belts - one groove at a time. 3 new belts in so, I gave up and took it to Motorcarman - he found and fixed the problem. S-type 3.0L dampers were scarce, and word was the Jag Supplier in Canada had succumbed to the Obama (so-called) Recovery and Jag was looking for a new supplier. He found me one in Houston and I retained the old one for refurbishment by the Damper Doc since I have 2 S-Types. For now I still have it in a box in the shop in a delaminating state. It was making a very slight wobble, almost indistinguishable - in fact, I had an autozone lifetime repl. alternator on there and persuaded them the pully was one groove out of alignment and got a new replacement which also didn't help. Belt on 3.0L comes from Crank-pulley to alt. So look at the nearest pulleys on either side of your crank to see if alignment maybe looks slightly off for an indication - or any wobble.

But yeah, bonding delaminating is the problem. Allegedly the damper-doc can fix you up.

Thanks for the additional commentary.

I have to work out the logistics of having the car down for a few days.

It occurs to me that I just might kill two birds with one stone. I've been experiencing a peculiar vibration that I haven't been able to nail down.

Hmmmmmm.....


Cheers
DD

$1000, owch...

I would have thought that 'borrowing' a car from work would be the least of your problems whilst you are going about this repair. ;)

Too nerve wracking, and too much rain this time of year ! :-)


Cheers
DD

it made a sqwuak noise, i just got a remanned unit from motorcars. i think its was 2 or 300

I think Motorcars (or BPI if you have a wholesale account) sends their dampers to be repaired by someone like Damper Doctors etc.

I had to send my 1992 4.0 XJ40 damper out for repair because it came apart and squealed. A buddy had a 1995 X300 that did the same thing and a new one was about $800 st the time. I sent it to damper doctor and had it repaired for around $200.

bob gauff

Update.

Took the balancer off this morning and you guys were right. It was clearly delaminating.

Cheers
DD

Had balancer re-bonded, reinstalled, the mystery is sol-ved [imagine Jacques Clouseau accent and intonation] :-)


Cheers
DD

Do X308 use the same harmonic balancer?

I don't know but it's a virtually certain bet that the V8 engines use a different balancer than the 6-cylinder engines. Not sure if they have a history of bonding failure.

Cheers
DD

DON'T REPLACE THE DAMPER until you test it to see if that is the problem. I thought mine was failing also due to squealing on cold start. But Bob Gauff told me how to test it and I discovered there was nothing wrong with it. The problem was a slight leak from the water pump and water getting on the belt. Doesn't take much water to cause a belt noise.

You test the damper by taking some white paint (I used white-out) and put a dob on the timing wheel and the other two flanges. Put all three dobs in line with each other. If the damper is bad the dobs will shift. Had mine marked for two weeks and no shifting at all. Some squealing though. Water pump due for replacement.

Looks like mine is bad too.