Loud squeal when car start from cold, stops when I press clutch pedal?

[mickburkesnr]

Right so the weather's getting colder and this Corolla has had a squeal the odd time it's started up. It doesn't squeal all the time when it's cold, but in the last week or so the car will start with a squeal and it'll go away when everything starts to warm up, but come back again after about a minute or two when I'm driving. I then notice when I change gear the squeal stops, and I localised it to when I press the clutch pedal all the way down the squeal stops. However, again, after about half a minute the squeal stops and doesn't come back again.

Does anyone know where this squeal is coming from? I thought it was belt squeal but the belts were changed a few months ago (as documented on the forum) but if the clutch pedal being pressed stops it then I'm wondering if it's the clutch? There is no clutch slip, I did try for that, so I think the clutch plate itself is OK. But I'd like a second/third/another opinion. 

[fordulike]

Might still just be belt squeal. When you are driving, as you dip the clutch, the engine revs drop. This causes the engine drive belt pulley to decelerate rapidly. This quick change in rotational speed could cause the belt to slip slightly, causing the squeal. Slight hardening of drive belt rubber in cold weather, doesn't help matters either.

If you pinpoint it to a drive belt, try using some belt spray to stop the squeal:

Belt Spray

 

 

[mickburkesnr]

I though this but if it was belt squeal it would change on revving the engine. This doesn't happen. I can rev the engine, the squeal's tone or pitch doesn't change. The minute the clutch is pressed in though the squeal stops until I engage the clutch again.

[fordulike]

The only other thing I can think of is clutch release bearing.

[oldcodger]

Have to agree with fordulike, think you need to rule out any belt problem first.

How about slackening off the belt considerably, then starting up from cold, or even removing it , to prove the point.

If it was in the clutch, does not matter what part, you need to replace the whole assembly, false economy not to.

The flywheel face might also need reskimming,  all a big diy job. c £300+ from places like Mr. Clutch .

Not something I have experienced but suppose it could also be a screaming crankshaft or gearbox shaft bearing ?? ie when you have pressed the clutch in then the load is reduced on those parts ?   Gearbox oil ok ?

 

[mickburkesnr]

I'll slacken them off over the weekend I think and see. Only problem is that it doesn't happen all the time, just the odd time in the last week or two since the weather has turned.

There is an oil leak from the gearbox, I think it's the driveshaft seal? I topped up the oil before I drove to Ireland after changing the oil. So there was about 2,500 miles done between me changing the oil and topping it up, and when I topped it up it didn't go down much (if at all).