Squealing from Engine Bay!

[myatt1972]

My coolant sensor only puts a light on, dont think it makes a noise.

[Ian65]

Ian
 
When I picked the car up from the bloke he started the engine and he claimed it was the first he had heard it. He disconnected it and cleaned the contacts which appeared to work, until about 20 miles down the road and was then on and off for the further 180 miles home. If it was the fan belt wouldn\'t I hear that noise whilst out of the car?

The most common cause of the belt slipping is the viscous coupler going bad and starting to lock up. If this happens, when you rev the engine, it can\'t spin the fan fast enough and the belt slips.
If you\'re out of the car it\'s only on tickover so the problem wouldn\'t occur.
Next time it happens, give it plenty of revs and see if the noise gets worse.
You might even get a whiff of burning fanbelt.
It sounds like a mechanical problem to me rather than an electrical one but there again.......

[ossie747]

Have you tried disconnecting the coolant sensor when the noise is audible to hear if it stops?
Without actually hearing the noise I would say trial and error with switching components on/off until perhaps you manage to find the culprit.

I tried this and sometimes it works but not usually, I\'ll have to dig deeper re playing around. I must say this response is fantastic lads, thanks for all the suggestions.

[captainbizzaro]

Just turn the radio up:Giggle

[CHC (RIP)]

This is a real far fetched one - if the noise is only audible in the ....pit, its nothing to do with interference and a mobile phone by any chance?

[syebba]

Just turn the radio up:Giggle

Would you plz be serious & try to be of some assistance,that sort of comment,helps nobody at all:2Rolleyes
 
It\'s the sort of crass comment i\'d do:Giggle.

[ossie747]

Just turn the radio up:Giggle

I\'ve found that this is by far the best solution to the problem.

[David Nock (RIP)]

Now doesn\'t the coolant warning make a noise as well as put the light up??
Sooo... if the coolant\'s a tad low...just a bit....the engine will be fine but it would be in warning mode. But if the warning bulb\'s gone then the buzzer will buzz...and buzzz...and buzzzzzzzzz.....until it gets tired, then it might sound like a fly in a jam jar?
Disconnecting the sensor will probably have no effect since it will earth through the coolant for silence in normal use - warning fails safe?
So I\'d double and treble check for that little air bubble in the top of the rad that triggers the sensor.

[David Nock (RIP)]

Because as they get old, they become an unreliable piece of junk.... you didn\'t touch it and all by itself it started playing up..... you then fiddle with it a bit and it starts working again. They\'re horrible things that just act like an enormous brake on the engine. I\'ve had grief with these things on each of the last 3 1st gens I\'ve owned.
All electric now.... I\'ve seen the light. No hassle.....reliability..... more responsive engine.... no flymo sound effects from under the bonnet...... I\'ve seen the light!

Refresh as to why doing next-to-nothing achieved a fix on Sid Vicious.

Thinking back to when I took the brass pin out...I was a bit disappointed not to find anything and just pushed the pin back in.....and the pressed it a bit with my screwdriver! I think now that the oil valve might have freed off as I pressed the pin in and out?

In 25 years I might have to do the same again...hopefully.

[myatt1972]

Its on the slippery slope now David so will probably only last 15 years till next time :chat

[Ian65]

Refresh as to why doing next-to-nothing achieved a fix on Sid Vicious.

Thinking back to when I took the brass pin out...I was a bit disappointed not to find anything and just pushed the pin back in.....and the pressed it a bit with my screwdriver! I think now that the oil valve might have freed off as I pressed the pin in and out?

In 25 years I might have to do the same again...hopefully.

Keep an eye on your temp for the next few drives Dave because although 8/10 these fans start to go stiff, sometimes they can go the opposite way and start to \'freewheel\' so that the fan starts to spin slower and then doesn\'t cool the engine.

[David Nock (RIP)]

Yes, thanks, I had thought of that. It\'s still making the old wooshing like a wind tunnel when I accelerate so may be OK. Will watch it though.

[ossie747]

Now doesn\'t the coolant warning make a noise as well as put the light up??
Sooo... if the coolant\'s a tad low...just a bit....the engine will be fine but it would be in warning mode. But if the warning bulb\'s gone then the buzzer will buzz...and buzzz...and buzzzzzzzzz.....until it gets tired, then it might sound like a fly in a jam jar?
Disconnecting the sensor will probably have no effect since it will earth through the coolant for silence in normal use - warning fails safe?
So I\'d double and treble check for that little air bubble in the top of the rad that triggers the sensor.

I think you could have hit the nail on the head here Dave, didn\'t think about the bulb having gone. I can confirm that there is no shortage of coolant as it\'s literally full to the brim. I\'ll check and let you know although it could be a couple of days due to work at the mo.

[David Nock (RIP)]

On thinking about this, bulb check is simple - do all the warnings come on when the key is turned to ignition? If not the check relay (\'U\' shaped metal can thing on the inner wing) wants looking at.
Also the warnings trigger an electronic chime.....put the sidelights on with the door open....there\'s a whistle type electronic chime - I think it\'s the same one used for both functions?