Alternator Woes

Lee S

Lee S

Member
When I had my car in at Stealth, they changed all the belts and tensioners and water pump, etc, but after re-assembly and just before the rolling road tune-up, Vince called me over to have a listen to the squealing coming from the engine bay. It was still there !! I had noticed this squealing, twittering, tinkling noise coming from the engine for about a week before I took it in and thought good job it's going in. However, after all the work it was still there. What could it be?

Vince seemed convinced it was the energy saving pulley at the end of the alternator and suggested that I go back at a later date to have it sorted. £50+ for another energy saver or £20 for a fixed pulley. What would you more experienced folks recommend? Is this a common fault with the alternator? Will it make much difference to performance/economy/reliability by swapping this for the fixed version? Could it be anything else? Would a whole new alternator be a better idea or would that be a waste of cash? It seems worse at tick-over and it goes when the engine is pulling the car. Is this a sign of the energy saving pulley? We also noticed what could only be described as a light covering of rusty coloured dust on the alternator and pulley. Could it be the alternator bearings instead?

I have also had a spate of battery warning lights that come on for a second and then go out. That has happened about 4 times in the last 4 months. Is this linked or just coincidence? All electrical systems seem fine.

Thanks all.
 
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Hi Lee
First, I would always be totally comfortable with the diagnosis made by Vince but a second opinion is always good and may clear up that last 1% of doubt -
An article by Ben Williamson in the March 2009 edition of Audi Driver suggests failure of the energy saving pulley is quite a common problem on many Audi models. The symptoms are generally as you describe - belt squeel at idle, made worse if the power steering is used. The belt can also go slack under certain operating conditions which would cause the charging light to illuminate momentarily.
The article also suggests the belt tensioner is designed to operate with the special alternator pully so the tensioner may not do its job if a solid pulley is used.

Cheers Spike
 
Just thought I would update everyone with this ongoing tale of woe. Got back from holiday yesterday and went out in the car this morning. The noise had got substantially worse. It was now making a grinding, rattling squealing noise with the battery light being on more than it was off. I was going down the M4 keeping the speed down a little and then it came. a big BANG and then silence. No more noise. Battery light now on permanently. Got to work, took the bonnet off and I found the alternator pulley wedged in the OSF chassis leg and the belt just resting on the now bare shaft. I took the belt off altogether just for safety.

I am hoping that the battery will last enough to get me home tonight and then onto the garage in two weeks to get fixed.

The bearings inside the pulley were absolutely wrecked. It has obviously been going for a while.

Looks like it should be an easy fix though. New pulley and belt and away we go.

Questions:

Will it be OK to drive like this? Obviously I have no charging or CC compressor, so how long will my battery last considering I have had no problems with the battery before and it is original.

Also, would it be wise to replace the tensioner as well as the belt and pulley?

Cheers,
 
you power steering will drain it hard as you turn, so will the hydraulic clutch when changing gear. Front lights are 50W so I wouldn't bet on it. May be borrow a charger or buy one (which can be useful when you're away anyway) just in case.
 
I could be wrong, a typical lead acid battery is not designed to handle deep discharge so you may even shorten your battery's life to let it go completely flat. But this can easily be googled for fact or not.
 
Typical. It was all grey and wet as I drove home, so I had to have lights and wipers on for 5 mins or so. Other than that it went fine. Managed to drive the 17 miles home with no problems. I have it booked in at Stealth now, so it will be sorted the day I get back from my business trip. Hopefully it will be a nice bright day and the battery will last the 80 miles or so to get there for Vince to fix. If not I will have to call the AA wherever it stops.

If the battery runs flat whilst driving, will the engine still run or will the ECU/control units fail and the engine stall?

I guess I could get a Maplins solar charger to trickle charge it whilst I am away. That would keep it topped up when not in use I guess.
 
I've been given one of those maplin solar trickle charger. It generates about 30mA on a good day, just about enough to feed the alarm system :)

Good luck!
 
Well drove 2 hours up to see Mr Vince again today in howling winds, driving rain and terrible light. Sod's law really. The one day I don't have an alternator and I need lights, wipers and de-misting and I have to limp along on battery power alone, just after having lovely weather for the last week or so. Ah well... Got there without issue and the battery was still strong after the drive.

Vince has replaced the belt and fitted a new freewheel pulley. All is well now. The light is off, no horrible noises and everything works fine. However...... :rolleyes:

They must have had the battery off for a period as they removed the alternator to fit the new pulley. The date/time needed resetting on the dash. The stereo seems alright though. Didnt need any codes inputing. Good. But now neither of the front electric windows respond to the one touch press. They go up and down fine if you press and hold the switch, but if you give it one good jab it no longer goes up/down all the way as it used to. Is this something that could have been caused by battery removal? Is it fixable or is something broken? It's both sides too. The only other thing done today is Vince used the VAG-COM to reset the long-life service indicator as he didnt have time last time. Could something have happened here too? Any ideas anyone? Is there anything I can do to remedy this myself?

Cheers,
 
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fix it yourself in less than three minutes;
press + hold the window button. let the window go all the way down. Hold the switch down for a couple of seconds. Then to the top, hold again. Repeat to the bottom and then try again with the "one shot".

Repeat for both sides.

Bret
 
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