[SimonB]

What would be the primary symptoms of an alternator which is not performing properly, specifically one that might be about to seize (and don't say take the belts off and check )

Also, I had an episode today after I climbed in the car and started her up, she died on me. This happened about a dozen times - switch on and she dies if I don't keep my foot on the accelerator. It wasn't as if it she shuddered before stalling, she just died. Eventually she took and held her idle revs. Any ideas?

[4ePikanini]

could be many things but the first thing that sprang to mind was the cold start valve overfueling. Go and check for black spitting where she was standing when you tried to start her over and over again.

[Family_Dog]

Simon, it sounds as if your alternator is presenting a heavy load to your engine whilst idling. This could be caused by it attempting to deliver an excessive rate of charge (not too likely, unless your battery is severely drained) - although the drop in idling speed should be compensated for by the vehicle's Idle Control Valve - or it might be due to a mechanical problem with the alternator, such as a bearing beginning to seize. This would normally be accompanied by some sort of metallic scraping sound.

You might want to get it checked out fairly quickly, because if the alternator does seize, it could perhaps snap your fan belt, thus creating an even bigger problem with an over-heating engine due to no water-pump operation or possibly fan. I'm not sure how the Paj's water-pump and fan work, so this is simply surmising, but those fancy new fan belts tend to be very expensive too.


-F_D

[CATS]

First check the basics, if you have not already done so. Is there not maybe a loose connection on the battery? This could lead to an undercharged battery as well as a drop in current from the battery under normal operating.

Trying to think less expensive here

CATS

[SimonB]

This would normally be accompanied by some sort of metallic scraping sound.

Well this is the concern - for a while I have had a "belt squeal" but only when cold.. but I'd say it's more metallic... but two mechs I have spoken to have said that's a belt. I've checkeed the tension. Looks fine. Sprayed belt dressing where I can.

My gut feel says it's a bearing on it's way out which explains
a) low charging voltage 13.6V
b) the squeal
c) the much higher resistance when cold, causing the engine to die suddenly.

I would bet it's not a fuel problem, because it starts fine and runs evenly at about 1000 rpm with foot gently on the accelerator. As soon as I managed ot get the motor to run for more than a couple of minutes it was fine and idled perfectly

BTW, it is due for a service in the next 500km anyway

[HBannink]

An alternator does not just give in it usually gives ample warning. First sign of bearings going is a rumbling sound that can be traced better with a long screwdriver held against the ear and the other side pressed against the front or rear of the alternator. Brushes are favorite to wear down and can be seen by a dim warning light or a low charge rate. This is a simple part to replace and a new set from mitsu is about R 40-00, the only specialist tool you will need is a soldering iron and some solder. As for the belt screeching it can be due to being too loose and after a start it works harder to replace the used energy for the start. A piece of normal candle held under the belt while running would lubricate the belt and not perish the rubber compound. Check the condition of the battery as a faulty cell can put unnecessary strain on the alternator and cause low voltage that can confuse the computer. A quick check is to open all the cells and let the engine run if any cell starts bubbling it should be checked out by a specialist.

[SimonB]

Same thing happened again this morning.

Startup with usual squeal, and engine dies immediately you take the foot off the accelerator. Not even a splutter or cough. If I start her up and then rev for a minute or two at around 1500 to 2000rpm then she idles properly thereafter.

[SimonB]

Ok, so it seems were closer to the problem. The tensioner pulley bearing is shot, as is the compressor bearing. The alternator itself seems ok, but the guys suggest to replace all bearings at the same time, together wiht the belts. The fact that the engine dies immediately after a cold start could be as a result of the bearings, so that say to change those first and have a look afterwards.

Alternator charging is fine apparently as my NL monitor is underreading a little.

[SimonB]

Ok, so it seems were closer to the problem. The tensioner pulley bearing is shot, as is the compressor bearing. The alternator itself seems ok, but the guys suggest to replace all bearings at the same time, together wiht the belts. The fact that the engine dies immediately after a cold start could be as a result of the bearings, so that say to change those first and have a look afterwards.

Alternator charging is fine apparently as my NL monitor is underreading a little.

Amazing what opinions people offer without really looking at the vehicle.

The tensioner pulley was incorrectly installed such that it was misaligned, and the alleged rumble on the bearings was the v-belts. All bearings were removed and checked.

The cold start idle problem was because of a dirty fuel filter

The alternator is 100%

The only issue is "overrun" on the starter motor which must be attended to - Dunno what this means but I'll get the starter motor overhauled sometime soon, and this actually the cause of the metallic squeal I hear when starting the the engine when cold.

Oh, and I can heartily recommend ANG Service Centre for work on Pajeros in Cape Town - Alan seems to know his stuff and his attention to detail is amazing.

[JDV]

Hi Simon,

What's the adress of ANG Service Centre please?