Alternator fault

Got an annoying shrieking noise on my 300tdi.

Only happens for about the first mile of driving. Stop and it a good rev it goes away and Its hard then to say where the noise is coming from.

Have swapped the fan belt for a new dayco one, swapped the belt tensioner pulley as the bearing was a bit noisy.

Buggers still doing it.

Sounds like the noise is coming from the alternator side when I am driving.

Could the alternator be a bit knackered?

Driving me nuts, good ideas appreciated.

Ian

Just check the water pump for play, mine collapsed and made one mighty shrieking noise, I thought it was the tensioner.

You may need to swap the whole tensioner not just the pulley, as they wear at a slight angle making the belt screech. If not look up penny trick on the stickies in 300 TdI I think. It didn't work for me but it might help diagnose.

Hi Kes

Thanks for the reply. I did swap the whole tensioner.

I will take a look at the pump and see if there is any play in that.

Strange thing is it only does if for about the first mile then it's fine. Part of me thinks ignore it but I don't really want to trash it just in case it's something more like the water pump.

Will take another look tomorrow in the daylight

Oh bugger. Investigation shows a weeping p gasket. Reading up it looks likes its either an easy job or a bugger if the 3 bolts won't come out that go into the block.

Anything else to watch out for. Will have a good look at the pump at the same time...

Ian

Get a new set of bolts (cheap), yours will be corroded. Ensure you get a metal P gasket and not fibre. Change the pump anyway. Make sure you have coolant ready before you start. Flush the rad, heater and block out while it is in bits.

Read up on the correct way to fill the coolant (its on here somewhere). Get a proper viscous fan spanner (also fairly cheap)

Thanks Kwakerman!

Will get all those parts on order. Going to throw a new rad on as well as its a bit knackered.

If the bolts are corroded are they a pig to get out?

Ian

Nearly all stripped down. New parts tomorrow and away we go

Smear of silicon on P gasket is advised, it's better to be sure than have to do it again.

Thanks Kes, that was going to be my next question, dry or a smear of sealant as belt and braces. Don't want to be doing this again in two weeks

Back to the original issue had a guy call in last month convinced of a noisy alternator and a brief squeal at starts of journeys
Turned out to be a dry collapsing front prop uj

I used to have a couple of shorter polyvee belts lying around some narrower but they were shorter and ideal for fitting in place to say miss out the alternator pulley or pump. Certainly only a worst case thing when tracking down noise was tricky and defo only for a very short run but they worked for me really well
Best of all they were free from the scrappy )

found out today why my alternator was making funny noises and producing random voltages: