scratching my head over this one so thought I would appeal to you fine gentlemen (and women!) for any ideas.....

Engine is a Pinto 205 block
Car has been off the road for 18 months - just trying to get her back on the road again....

On startup I get a horrible screaming - just like a slipping fan belt... carries on for a few minutes and then the noise just stops.

Checked belt tensions - all seem ok

took belts off and hand turned the water pump and the alternator (only things being driven) and they turn freely.

I did wonder if it was to do with something warming up - but when the noise stops - if i switch off and start again the noise comes back....

I know it's a wide open question - but if anyone has any bright ideas what to check on i would be most pleased to hear them....

had similar when the belt was loose and the alternator was fully on load, once the load was taking off, it battery recharged, the screaming dropped away.

Can you correlate the noise with the alternator charge?

Does it happen every time?

If it does, try firing it up with the fanbelt removed (it'll run fine for a couple of minutes with no drive to the water pump). That way you can definitely rule out the fan belt, water pump and alternator.

Start it up without the water pump/alternator - ie belt off.
Clutch in/out, ?
In gear or not?

Eliminate or exaggerate to narrow it down a bit

has it go oil in it?
Drain it and try again. No not really!

Starter motor not disengaging? I had this on one of my cars - the noise like you said is a screeching that sounds more like a belt!

some interesting ideas..... things to try tonight

Don't think it is starter motor as I have just replaced it... (it died in the worst way and caused a surge which fried my megasquirt and fuel pump relay!)
noise was present before starter motor change as well.

given its a Pinto that has been stood for 18 months, I was worried it might be the cam shaft not getting oil from the spray bar - but it isn't really the noise i would expect from that....

thanks all

quote:

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Originally posted by DaveFJ

I was worried it might be the cam shaft not getting oil from the spray bar - but it isn't really the noise i would expect from that....

thanks all

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Alternators that are on their last legs electrically can make howling noises when under heavy electrical load.

Edit to Add ==== you have checked the alternator pulley ? Ford alternator pressed steel single V pulleys were notorious for the sides of the pulley opening out causing the belt to run in the bottom of the pulley not in a proper Vee grip this causes belt slip under the heavy heavy load --- in this case replacing the lost charge after start up. Tigthening the belt won't help much.
We used to replace the Ford pulleys on Lucas ACR alternators in Cortinas with BL Marina ones which were cast steel and didn't suffer from the problem.

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[Edited on 18/7/16 by britishtrident]

If it makes the noise with the alternator drive belt removed check for air leaks and also the crankcase venting system. A length of rubber hose held to one ear with the other end near any suspect areas is useful when trying to locate noises, better still a mechanics stephascope with the probe removed .

a shot clutch release bearing makes a horrible noise.

Exhaust manifold. Check all the nuts/studs and check for sooting.

OK... thanks for all advice... removed the belt and noise went away
... so that leaves either alternator or water pump... the fact that it goes away suddenly makes me tend to think alternator....

It's a small denso alternator and I can see that the bottom of the pulley groove is a little polished... so I am guessing that it is running down there.....

Setup hasn't changed so I am wondering why this has started happening... could the alt be on the way out? Would it be significantly harder to turn under load if it Were?

[Edited on 18-7-16 by DaveFJ]

[Edited on 18-7-16 by DaveFJ]

Cheap fix first is to try a new belt, if the pulley is a little wide and the belt a little worn combined it will slip.

Agreed - I will be getting a new belt - but I am also going to do a little work on the mounting of the Alternator to try to make it easier to adjust tension....
Unfortunately there is a pipe in the way preventing a direct line of sight, so I can't use a turnbuckle type arrangement... so just spending my lunchtime dreaming up design changes!

A battery that is not in the best of health will put a heavier load on the alternator after start-up.

[Edited on 19/7/16 by britishtrident]

Brand new battery

Problem now solved
Wasn't until I went to fit the new belt that I realised how worn the old one was!... should be 10mm wide... it was worn down to 6mm!!! Something to keep my eye on!
Thanks all for your help and advice...

[Edited on 21-7-16 by DaveFJ]