Suspected alternator bearing please help

Austin09 · **Posted:** Thu Oct 01, 2015 10:35 am

Hi guys,

I'm investigating a noise on start up, doesn't last more than 20 seconds or so and only does it when the engine is not up to temperature.

It sounds like a bearing or a belt. I'm thinking power steering belt may want to go a tad tighter. When examining the belts, there seems to be a slight wobble on the PAS belt but there isn't much inflection on it, its pretty tight but not overly tight.

My concern is its the water pump, is this a symptom? If so is it a ball ache to change?

DarrylH · **Posted:** Thu Oct 01, 2015 12:23 pm

I'd expect it to be the alternator or power steering belt. Probably just needs tightening a bit

Austin09 · **Posted:** Thu Oct 01, 2015 12:31 pm

Cheers,

Will tighten the PAS belt - its newish and may have stretched. I had to replace the left hand thread nut on the tension when I did that job because some numpty ruined it. At least that will be straight forward!

Endoman · **Posted:** Thu Oct 01, 2015 12:37 pm

Alternator belt screech is is a familiar sound first thing on this housing estate.

tr7v8 · **Posted:** Thu Oct 01, 2015 4:33 pm

Worth checking both, normally the alternator belt. Worth a close look & changing it they are about a tenner!

white944 · **Posted:** Thu Oct 01, 2015 7:46 pm

Take both belts off and see if the noise goes away the next morning.

Austin09 · **Posted:** Sun Oct 04, 2015 2:06 pm

Is there any way of oiling the alternator bearings?

Waylander · **Posted:** Sun Oct 04, 2015 5:25 pm

no there is no way you can oil them, take it off and get it rebuilt by an auto electrician, cost about £90-100 will outlast the car then

Austin09 · **Posted:** Sun Oct 04, 2015 5:38 pm

Could it be anything else?
The sound is in that area for sure. Could be the belt but it's in great condition.
Spinning the bearing with the belt off or testing with a stethoscope and it sounded fine but hard to see what else it could be.
I can get a rebuild kit for £15 and restore it.

Waylander · **Posted:** Sun Oct 04, 2015 9:13 pm

Start it without the belts on, definitive answer. If it only squeals at startup then almost definatley the belt slipping, you should have a max of 10mm deflection in the centre of the belt.

The power steering belt will only slip when the car is on full lock with a bit of pressure on the steering wheel

To rebuild the alternator you will need a few special tools not least of which is a press for the bearings

when were the belts last replaced, they suffer the same fate as the cam and balance belt with age, and should be replaced every 4-5 years.

one of the cheaper things to buy for our cars

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Suspected alternator bearing please help

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