Hi fellows,

I have a 98 1.0 Polo and I could really do with some help to identify the cause of a rather "frightening" sound that has been driving me mad over the last couple of weeks. I'll fill you in on the details:

It starts and runs normally for some miles, but then, there comes a whining noise that grows into a screech and a lot of rattling that remains even when the engine is only idling and in neutral. At first I thought it was the secondary belt, then the valve train, and many other things, such is paranoia. Finally I discovered that the noise and the rattling appear to come from under the engine, apparently from the bell housing. It breaks my heart to hear it, so I'm not using the car. It was suggested to me that it has to do with the clutch thrust bearing, but I'm not that convinced. since I have never heard such a noise associated with the clutch. Is there anyone out there who can cast a light on this issue and set me on the right path? I would sincerely appreciate it.

Enjoy your day, whoever reads this post.

Does the noise change when the clutch pedal is depressed?

It could well be the thrust bearing. If it's been run dry of grease the metal on metal contact between bearing race and rollers will cause a screech, and probably a rattle when the clutch pedal is released...

Edited 5 August, 201313 yr by Phataz1

Identifying noises that you can't hear is always difficult.

The first thing that came into my mind when I read your posting was - - - Clutch release bearing (or thrust bearing)- - -Mainly because there is not much else in the bell housing that can make a noise.

As said above, does pressing the clutch pedal make any difference?

Before you do much else, you really ought to make sure that it IS the release bearing that is at fault, as it is also possible (though less likely) that the noise is from the gearbox.

A simple test is (obviously whilst the noise is present) with the car stationary, put it in gear, this will lock the gearbox,now press the clutch and start the engine - if the noise is still there, then it ISN'T from the gearbox. BUT before you go pulling out the gearbox, make sure that the noise is not from the starter motor which MIGHT not be disengaging from the ring gear - Have you had any starter problems???

A 'listening stick' (length of dowel or long screwdriver or even a Mechanics Stethoscope) (not very expensive) might help you to pin-point the noise.

Regards.

i had exactly the same noise and in my case it was the thrust bearing, took the gearbox off to have a look and half the balls that were supposed to be in the thrust bearing were sat in the bell housing

Thank you indeed Phataz1 and caretakerplus for your advice. I shall test the gearbox as recommended and will post the results.

Nice of you, guys!

Would be interested in the 'results' of this...

(shame alot of threads dont end up with the results to help others)