Bit of a screech!

Post by **grahamt7** » Thu Mar 30, 2006 11:10 pm

Scarlett has developed a brief screeeeeech

when changing down the gears (and still having reasonably high revs).

Any clues chap(esse)(s)?

Also now developed nice "exhaust blowing" type rasp.

Just had an unleaded head fitted and I'm still doing the initial milage before it is retightened.

Cheers for any info.

Graham.

Post by **chrisd87** » Thu Mar 30, 2006 11:38 pm

Are you sure the fan-belt is properly tightened?

Post by **grahamt7** » Thu Mar 30, 2006 11:40 pm

No idea, man from the AA replaced the fan belt about 5 months ago. I'll try to check in the morning. Cheers.

Post by **Packedup** » Fri Mar 31, 2006 12:46 am

I've yet to fit a new belt and not have it go through an initial stretch and need a quick nip up, so if it's causing the noise or not it's probably a good idea to double check it's tight enough

Post by **Cam** » Fri Mar 31, 2006 2:05 am

Does it happen when your clutch pedal is pressed down only? If so then it might be the carbon thrust bearing. Let's hope not though as you have to remove either the engine or gearbox to get at it.

Post by **grahamt7** » Fri Mar 31, 2006 7:16 am

It happens when releasing (raising) the clutch to re-engage gear. Specifically when going from 4th to second but also a little going from 4th to 3rd. I think the thrust bearing was changed last October.

Graham.

Post by **RogerRust** » Fri Mar 31, 2006 7:38 am

You probably have a mouse behind the dash board. I had that problem once with a Ital.
Sorry couldn't resist it.

Post by **chickenjohn** » Fri Mar 31, 2006 8:57 am

Try greasing the clutch linkages and get some oil on the pedal shaft. If that doesn't work, then I'm afraid, as Cam said it could be the release bearing.

Post by **bmcecosse** » Fri Mar 31, 2006 9:55 am

4th to 2nd is going to wreck the syncro very quickly - unless you are double-de-clutching. Don't do it. Tighten the fan belt and hope that's it - but likely it's the carbon thrust.

Post by **rayofleamington** » Fri Mar 31, 2006 10:23 am

changing down 4th to 2nd will cause a rapid rise in engine speed as you release the clutch - this is likely to add to any problems with a slipping fanbelt (the rate of change of speed means a lot more load is put on the belt as it has to accelerate the alternator very quickly)

Post by **bmcecosse** » Fri Mar 31, 2006 10:50 am

Modern L driver teaching is NOT to go down through the gears - brakes for slowing and gears for going! I don't entirely agree with this - but you should certainly try to minimise wear and tear on the gearbox - unles you like rebuliding gearboxes of course!

Post by **rayofleamington** » Fri Mar 31, 2006 9:07 pm

Modern L driver teaching is NOT to go down through the gears

The guys who teach this are complete idiots. Gearboxes are designed and tested to be robust against upshifts and downshifts. Gearboxes will wear out quicker if you shift in a heavy handed way (drastic increase in synchro wear) but if you drive properly the clutch and gearbox will last just fine.

This lack of proper driving skill is very dangerous and occaionally leads to accidents. Modern cars have heavily over-servo'd brakes so if an engine stalls whilst driving, often people just rash complaining of 'no brakes'. I've read of many instances of this in the press, and so far none of the articles have raised the really obvious point - if the driver had not been useless, they would have used engine braking, and whilst using the car momentum to turn the engine, the servo would have been driven and the brakes would have been fine.

Maybe if people are killed, the motoring industry will lobby parliament to make basic driving skill (including engine braking) a compulsary part of the driving test.

Post by **Peetee** » Fri Mar 31, 2006 9:32 pm

The guys who teach this are complete idiots.

I can see where your coming from but that's a bit severe.
I would suspect they are suggesting it's not good to rely on the existance engine braking. I have driven more than one engine management equipped car that has precious little engine braking ability. more alarmingly the retardation does not seem to be consistant with engine revs. It's as if the engine management system just doesn't understand what it is supposed to be doing.

Post by **grahamt7** » Sat Apr 01, 2006 12:12 pm

Fan be3lt tightened, can't get it to screech now.

Post by **bigginger** » Sat Apr 01, 2006 12:53 pm

Loosen it off again then

Post by **bmcecosse** » Sat Apr 01, 2006 2:15 pm

Well done !
On subject of poor driving - the lad whose throttle stuck open recently - and he continued down the A1 for miles on end at high speed before rolling the car - If this happens to anyone on here - SWITCH IT OFF ! I would have thought that was obvious. Of course on modern car - just switch it off by one notch - then the steering will not be locked. Alternatively - stall the thing by pressing the brakes really really hard - before they fade away to nothing as seemed to happen with this lad - he slowed the car on brakes for mile after mile until they had faded out! His performance must deserve the Worst Driver of the year award!

Post by **chrisd87** » Sat Apr 01, 2006 2:37 pm

I saw that in the paper too! He seemed to be under the impression that if he turned the engine off, he'd lose the steering and brakes. Surely he must have known that it is possible to drive a car without power-assisted everything! By the sounds of it he was very lucky to survive.