There is a squeal when I first start the engine, it stops after a few seconds, and when it does stop, the alternator starts to charge. I have a separate voltmeter aside from the gauge on the dash. to confirm this action. I have replaced the alternator, the idler, and the damper, but after the last time, it seems to be worse. Is there some sort of load on the charging system when first starting cold, as it doesn't happen once warmed up and restarted several times?

 

Itis just a bit of belt slippage.
Any sugar-based liquid such as molasses or golden syrup applied lightly to the belt will give it greater grip.
Doesn't take much more than a light smear.
Alternatively industrial machinery outlets have belt gripping "sticks" which are basically semi solidified sugar.

 

Caution on tightening the alternator belt too tight as this puts excessive wear on the alternator front bearing , had one go out on me but is an old X year old bearing

 

Search for DELAMINATED CRANK DAMPER or HARMONIC BALANCER.

https://www.jaguarforums.com/forum/x...estion-103084/

https://www.jaguarforums.com/forum/x...cement-144126/

 

I have already replaced the damper pulley with a refurbished one, new belt, new alternator, is it possible there is an electronic load on the alternator as it starts charging as the noise goes away?

 

the alternator will be under a high natural load after draining the battery after start , on top of the seat heaters , cabin blowers and maybe headlights

It is a large alternator rated at 120 amps to handle that

White stripes on harmonic balancer for easy check of a good part received ? no belt removal needed

Good pic from Al that may be in Motorcarman's links

My alternator front bearing gave up smoke as a tell saying look at me but that would not account for your charging indication lagging observation unluss the alternator guts were prevented from spinning ( bad bearing acting as a brake )

You can also cautiously feel the alternator pully area for heat

The alternator belt is sensitive to size as there is little adjustment throw ( or belt stretch ) of that long adjustment bolt from the front engine block , I measured my belts out as a new Jaguar stamped part # s from the previous owner

Alternator fault dash light ?

Between cold and warm engine start a warm engine requires less drain of the battery

There may be a time lag from the voltage regulator ( bad ) that doesn't in turn put a load on the pully which may be counter to your immediately timed ( during cranking and after ignition key release ) observation

The alternator should always be alive or active during the whole start cycle unlike other items

Alternator field excitation ( voltage regulator function ) Fuse # 10 right engine bay fuse box is hot while the same fuse box fuses # 12 , #14 , and # 16 are hot to power the ECU and engine sensors . So there is no alternator "cut out / load shedding " only it's electrical drains downstream of alternator like cabin blowers which are gated by the relays in the corners of other fuse boxes going back open / relaxed / no continuity power contacts

 

Oddly, my car appears to do the same thing… less so in the summer when ambient temps are higher. I’ve been trying to keep the battery on a tender, which seems to help somewhat. Car is basically parked for the winter so will likely revisit this in a few months.

 

Mine did the same on cold starts recently as I hadn’t tightened up the “fan”’belt to its old setting after replacing a noisy water pump with worn bearings as I was trying to avoid over tightening.
Didn’t take much adjustment to quell it without the belt being excessively tight.

 

Thanks for the detailed info, I tightened the belt just a little bit, it stopped the squealing for now, as mentioned earlier, the idler pulley, alternator, belt, and damper have replaced in the past year, time will tell.......