Jump to content

XK 8 Faulty Alternator – Symptoms And Cure.


Recommended Posts

XK 8 Faulty Alternator – Symptoms And Cure.

I suffered this last week and it was a little confusing so I thought that I’d post my experience here in the hope that it might help and reassure anyone else that develops the same problem.

The car had been standing for a week and on starting up I noticed that the Odometer/mpg display was flickering, at this point everything else seemed normal, no fault indications. Then I noticed that the Voltmeter had gone up to 17 Volts, the first time ever that I had seen this go over the top dead centre position.

I tested the battery voltage with a digital meter whilst the engine was running, this fluctuated from around 11 Volts up to 17 Volts, something wasn’t right.

On looking more closely at things this is what I discovered :-

There was no indication of Alternator failed or failing – this confused me more than I usually am.

Odometer/mpg display – flickering and going from normal brightness to very low brightness and then to very bright.

All other lights flickering.

Traction Control Fail message.

Stability Control Fail message.

Gearbox Fault message.

ABS Failed indication.

Autodrop on windows behaving even worse than usual !

Indicators “ Ticker “ making abnormal noises, double tick, fast tick and normal tick, usually the dashboard indicator not showing, not sure if the indicators were working or not, I didn’t check.

Gearstick locked in “ Park, “ on pressing the brake pedal the clicking that indicates that the unlocking solenoid was working was not there. I resolved this temporally by stopping and then restarting the engine. If this hadn’t worked I would have had to remove the TORX screw adjacent to the Gearstick and mechanically released the lock by pressing the lever under here.

When driving ( don’t risk things by driving any further than you absolutely have to ) engine RPM was sluggish to respond and seemed that it may have been limited.

There may have been more indications that I didn’t notice but this is more than enough to be going on with – I was already in full panic mode and didn’t need any top up of stress juice………..

A little later, having calmed down, rational thought kicked in and I exercised some of the few remaining grey cells that I still have.

It seemed to me that a faulty Alternator was the cause of all these problems, probably the Regulator Pack. I think that it was still providing some charge, hence no Alternator warning light, and even at times too much charge but that the charging voltage probably had a fair bit of unwanted AC voltage along with the very desirable and much needed DC……..

I went with this diagnosis and did some searching for a replacement Alternator. I found that there are a few options :-

Non-OEM Re Manufactured exchange guaranteed for two years – about £120

Non-OEM new guaranteed for two years – about £145

Original part, not sure about the guarantee – about £190

I went for the Non-OEM re manufactured one as not only was it the cheapest AND guaranteed but it was also immediately available locally. My local indy obtained  and fitted this for me, took two hours in labour costs.

Panic over ! Everything back to normal. The car that is, not that sure about me!

If you ever get similar confusing symptoms bear these notes in mind and don’t immediately roll up your sleeves and reach for the razor blades, you may find that things are not as bad as they appear, I hope that, like me, you will be lucky.




Link to comment
Share on other sites

A quick update. After leaving the garage noticed a squeal from the Alternator Belt area at certain revs. Took it back to fix and it turned out that the Pulley which came with the re manufactured Alternator was ever so slightly different so it was trying to push the Belt off.

Moral is very simple - save yourself work and/or hassle and check very carefully that the new Pulley is identical to the old one.. If in doubt put the old Pulley on to the new Alternator.

Link to comment
Share on other sites

View all the latest Jaguar leasing deals here:

Limited Stock*for early 2022

*Due to the on-going semiconductor issues, the supply of new cars and vans has been dramatically hit. If you are due to change your vehicle/s in the next year or so you will NEED to start looking now to avoid disappointment or potentially being without a vehicle.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...