During the last few days, my daily driver '97 XK8 convertible would on startup show a voltage below 12 volts on the voltmeter with its red low voltage RED warning light lit up. If I do not drive off immediately but let it idle for 1.5 to 2 minutes, the voltage would slowly and gradually creep back up to normal with the voltmeter pointer pointing straight up. Gents, please advise if the alternator or its parts such as voltage regulator and/or brushes are failing and need replacing?

Coincidentally, I've 2 weeks ago replaced the fan belt 7PK2322 with a 7PK2325 which has been quoted online as a suitable replacement. The vehicle on daily initial startup and immediate drive off would seem to lack power-steering assist and moan when you turn the steering wheel. Only if I sit and let it idle for a minute or two will the power assist return to normal. The power steering reservoir has been checked and the fluid level is normal. What is wrong with the power-steering assist and how can I remedy the situation?

Many thanks TIA.

 

First thing I would check is the idler arm to make sure the spring is getting the belt tight. They do loose some of the spring over time.
If the new belt was longer, it may not get tight on the pullies until it warms up enough to grab.
Keep us informed, sounds like one of the weird ones we get once in a while.

 

I agree with Wayne. Sure sounds like a slipping belt. (Thats good news)

John

 

My OEM belt in the parts museum also carries a 7PK2327 identifier along with the Jaguar part #, so you should be fine with the 2325 (2 mm shorter).

Give the pulleys a spin with the belt off to check they're free and not grumbling if you haven't done this already.

Also, don't place too much reliance on the reading from the car gauge - it's pretty approximate - check with a voltmeter. Since you're not reporting window resets and random error messages it's likely your battery is OK. Should read ~12.6V across the terminals when the car is resting.

 

Thank you Gents for your comments. I would try to determine if there is belt slippage due to belt stretch, and/or if there is insufficient spring tension in the tensioner.

I'm having difficulty in releasing the tensioner arm; a 14mm socket would not fit the nut at the tensioner pulley, but a 15mm socket seems just too loose. What size socket should I use to move the tensioner arm?

 

Be very careful there... Try a 9/16ths 6 sided...
But don't get frustrated and turn it of things don't feel right.

 

Mine loosens with a 3/8" drive ratchet. The drive of the ratchet - with no socket. My car is a 2006, though.
I always keep this picture close by when changing the belt (attached).

 

I don't understand how an imperial size bolt gets adopted. Since all my tools are metric, I'll just resolve to use an adjustable wrench for this job.

 

Do you mean your tensioner release bolt has a 3/8" drive hollow built into its face to allow you to slip the ratchet on? My bolt face is flat so cannot use your method. Maybe the newer version belt tensioners carry your improvement.

 

My wife's 2006 XK8 also needs just the 3/8-inch extension bar to fit into the square hole on the tensioner arm. No socket required. Sure makes it much easier to release....