Alternator Noise?

twaymouth, Jun 12, 10:43pm
I have a 94 Caldina (Diesel) that has started making a rather unpleasant noise, I think it may be from the alternator but I am not sure. I started by dropping the belt that drives the air con pump and power steering pump but the noise still persists. It sounds like the noise is coming from the cam belt area but it is hard to tell. Next I removed the alternator belt and the noise disappeared but the alternator appears to be fine, No movement in the pulley and its generating power fine. Has anyone got any ideas where I might look next!This is the sound with the alternator connected: http://www.supload.com/listen!s=hWDzVO.

intrade, Jun 12, 10:55pm
Sorry, - is no longer available!

intrade, Jun 12, 11:00pm
the most common noise on these would be the idler pulley from the airconditioning .does it got aircon!it be like a bird tweeting twititwitwit
nowif you removed all outer drive belt and its still there. alternator not turning then it can only be the cambelt or waterpump.

skin1235, Jun 12, 11:00pm
diesel alts also have a vac pump on the back of them for the brake vac assist, they (the vac pump) are usually supplied with oil to the vanes and rear bush and if that oil supply is failing the vac pump throws a squealing hissy fit
disconnect the banjo on the back of the alt and drop in a few drops of oil, reconnect the banjo and try checking it again - if it improves then you have found the cause, then find a cure ( oil gunk in pipes - is the usual cause)

ashwattau, Jun 12, 11:02pm

intrade, Jun 12, 11:03pm
skin1235 is probably on to it as it only done it with alternator and stoped when alt was off!

intrade, Jun 12, 11:05pm
check the main crank pulley is not loose . ! that sound is not a bearing but a flapping noise

twaymouth, Jun 12, 11:09pm
It is a newer 2C diesel with a cam driven vac pump, the pump hangs out on the rocker cover rather than on the back of the alternator. This leads me to believe that it may be the water pump however the noise went away when the alternator belt was removed which is strange as the alternator appears fine.

tmenz, Jun 12, 11:13pm
Is anything else driven by the alternator belt!
Have you checked all the alternator mounting bolts - sounds like a rattling clamp or mounting to me.
Belt tensioner or idler maybe - if there is one!

twaymouth, Jun 12, 11:13pm
The main crank pulley looks fine, It has no movement but produces a slight high pitched noise when the engine is run with no belts connected. Maybe the load from the alternator is upsetting it! Nothing else is driven from the alternator belt, I have checked the alternators bolts and they are all tight.

intrade, Jun 12, 11:14pm
the belts pull on the harmonic balancer . check that and check the belts for damage could be a cut on a belt making that noise also.

twaymouth, Jun 13, 5:13am
Thanks for the help, I am now fairly confident that it is the harmonic balancer making the noise. I will get it replaced and hopefully it fixes the problem.

intrade, Jun 13, 5:21am
if the harmonic balancer makes the noise then it be split in 2 peaces put it in a vice and find out if the outer parts move if they do then its poked .

bigfatmat1, Jun 7, 12:58pm
a whine can be caused by a phase out on the alternator would still charge ok but would prob drop away after you turn lights on ect