I took the Jag out for a quick spin today - first time I've had the chance in about three weeks. The plan was to give it a run, then park it on the drive and swap in the new headlamp units. I notice there's oil in the garage floor, which is odd. Just a few drops, but the old girl never usually leaks anything, ever (except water from the AC, which pisses out just above the lambda sensors).

Darkness came and I'd got both sides swapped, with just the grill and bumper to refit. Well, that'll do for now - I'll put it in the garage.

I jumped in and fired it up. It normally has a bit of a growl on startup, which stops after a second or so and it's usually just when it's cold. This time, the growl seemed louder. The engine fired OK, but there was a terrible whining noise. It was just like when you turn your bike upside down, spin up the rear wheel a bit, and slow it down with your fingers on the tyre. I turned it off straight away.

Then I saw a neighbour reversing down the road. Silly me I thought - it's just a straight cut whine from the reversing car. I fired it up again - same noise. I turned it off straight away and retired for the evening. The noise was not there with the ignition on but the engine not running, so it's not the fan.

I'll see if I can get my mechanic brother over here tomorrow. My first thought would be to pop the belts off and see if the noise continues. If it continues, could it be the tensioners or slippers? We've not checked the state of the chains at all since I've had it, and it's done 171,000 miles. I would have thought a lack of tension would lead to it jumping a tooth and trashing something. Maybe an ancillary is more likely and the noise will stop with the belt off.

Most annoying is it's the local car club's 20th anniversary rally in Ely on Saturday, and I'd sneaked it in to the BLARG day at Peterborough on Sunday. Bugger!

 

Hi theJPster,

My first suspicion would be that the noise has something to do with your work on the headlamp exchange. Is it possible that something has come into contact with a moving part, such as a belt-driven pulley, causing a rubbing sound? Or that something has obstructed the air intake nozzle on the air cleaner housing (which fits into a hole in the left inner wing), causing a change in induction noise?

Cheers,

Don

 

It's the alternator.

The car was fully charged all day Thursday because the battery was dead after 3 weeks standing. Friday morning, it was towed to the garage and the battery was flat again. The car was run for a few minutes and the alternator was hot and smelly.

So, fresh diode pack or new alternator?

 

Hi theJPster,

I'm not sure of the year or model of your car (always a good idea to add that info to your signature line), but did the garage confirm that the alternator was the source of the whine? If so, was the whine due to siezing bearings in the alternator? If your alternator is by Denso, it is quite possible you could just rebuild it with new bearings, brushes and rectifier. The rebuild kits I've seen are very reasonably priced.

Cheers,

Don

 

Yes, it was definitely the alternator. I've decided to put a new one on so I can refurb the old one in my own time. Are there any good guides online that people would recommend?

It's a 3.2, for the record.

Thanks,

JP

 

Hi theJPster,

If you search YouTube for "Denso Alternator Rebuild," or "How to rebuild a denso alternator," you'll find some videos that may be helpful.

Note that Denso is a former division of Toyota, so these are sometimes referred to as Toyota alternators.

P.S. If you add the year, model and engine (3.2L) to your signature line, others won't have to ask and it may help avoid getting incorrect replies to your questions. I still have no idea of the model year of your car, or if it's even an X300. You may discover that your alternator was made by Bosch rather than Denso.

Cheers,

Don