I replaced the alternator about 8 months ago and things were fairly normal sound wise. Then about a month ago this high pitch whine starts.
I assume it is the Alternator. It could be the air pump. This sound comes
from the area on the AJ6 engine where the air pump and the alternator
are located.
I really don't like to go into the alternator replacement again.
But, I do have the replacement process from the top on the AJ6 engine down to about 1 hour.
I only go under the car to get the belts lined up on the pulleys.

I'm thinking of repairing the old alternator myself if the current unit has bad bearings. The old unit which I still have needs a new diode pack.
For some reason the supplier didn't want the old alternator back as
an exchange.
I paid $130 for the current Nippon-Denso unit.
The Nippon-Denso units are now handled by Delco Remy now.

Ahhhh, the XJS demands more attention. My wife is getting jealous.

POR - Press On Regardless

 

This is where a mechanic's stethoscope comes in handy. About $8.00 at the local auto parts store


Nothing ventured, nothing gained !



With global marketing and manufacturing, and label engineering, everybody handles everything these days. Open a box and anything could be inside !

That's part of the fun, isn't it ?

Cheers
DD

 

Lubed for life bearing and/or bushing in that Nippo Denso?


New as opposed to rebuild, so no use for a core.


An alternator on my "low mileage" 65 Corvair made an awful racket.
Still charged, though!!! Wifey not happy, her car primarily. So, I took it apart. Wow, what a mess. Too far gone. Swapped it for a rebuilt one. Then the starter. Same mess. After a time, I devined that the car was low mileage. But, the engine and trans had been replaced, by a well worn pair.... Bought used , "as is" from GM dealer's used lot.
They did spring for resealing it's leaky transmission and balancing it's carbs. Looked nice. Black in and out. Ran well, but just a tad smokey. Oh, and Corvair oil leaks to chase down and fix...


Carll

 

Is there a possibility that it's the drive belt slipping as that can make a horrible screaming noise.

The alternator belt especially on high output alternator (120A) is high tension and will stretch with aging.

 

The noise sounds like a turbine type of whine.
It maybe the bearings in the alternator which is the only new
piece aside from the belts that was introduced into the engine setup.
But, most bearing noises I've heard are a roaring type of noise.
It is not like the screeching noise a slipping belt makes.
I do have a mechanics stethoscope. I forgot about it until Doug reminded me.

"Code Blue !"
"What? I can't hear you because of the turbine whine from the engine!"
"Get a stethoscope and another alternator, STAT !" "We have a sick kitty here!"
"I'm not going to have it's lights go out again while I'm on duty!"
Cut away to scene of Dr. POR holding a stethoscope to the XJS alternator.
- Episode of Dr. POR -

I replaced the belts while I was replacing the alternator.
I just noticed that those small vacuum hoses that are all over the engine bay
are in need of replacement. They are looking a little grimy and cracked in places.

Oh, when will I ever see daylight again, Miss Jaguar?

Regards,
P O R - Press On Regardless

 

Gee, I went on errands yesterday, my lumped 83 XJ wuzza six just purred.... It's serpentine belt handles the 140 amp alternator and other stuff so much better. Efans and ewater pump so much better. Load is
PS, AC, alternator only....


Carl