Noise goes when clutch pedal pushed down?

[PeteE30Tourer]

Just noticed when i got the car home tonight that there was a new and not very good noise coming from under the car with it idling at a standstill on the drive. To me, it sounded like a large bearing that had run dry, if you see what i mean. Anyway, when i pressed the clutch pedal, it went away. I'd also noticed that the biting point of the clutch was much lower on the travel of the pedal tonight than it has been and it grabbed quite quickly as i began to lift off the pedal.

So, does this mean my clutch has gone?

If so, what sort of damage (i.e. Ԛ£Ã”šÃ‚£Ãƒ”šÃ‚£) should i be prepared for in getting it replaced?

[smithy318i]

That would be your clutch thrust bearing.

[E30BeemerLad]

yep, Smithy hit the nail on the head, thrust bearing/ clutch release bearing.

Gearbox out job, whilst you're doing the bearing it is well worth considering doing the clutch unless it is pretty new. And also replace gearbox seals on the input & output shaft.

Oh and then stick a Z3 short shift!

[smithy318i]

I don't know what car you have, so some prices:

Whole Clutch Kit from ECP.

M10 77.50+VAT
M20 92.00+VAT
M40 75.99+VAT

[Andy325i]

If the noise dissapears when you press the cluch pedal down it is the bearing on the input shaft to the gearbox (I.e. when you depress the cluch you disconnect the gearbox). If it made the noise when you pressed the pedal it would be the thrust bearing as this is when the thrust bearing is under load.


Andy

[smithy318i]

You (I) learn something new every day!

[E30BeemerLad]

:yeahthat:

[PeteE30Tourer]

The car is a 325, i.e. M20 (always forget to state this in my posts!)

I'm confused by the answers here though - some say it's the thrust bearing, someone else says it's the input bearing to the gearbox.

I'd already looked up the clutch kits from GSF, but do these include both bearings and the clutch itself? As Beemerlad said, it's got to be worth doing everything whilst the gearbox is out.

I've already got the Z3 short-shift - took me a whole weekend to fit (mainly due to that nasty little bearing at the back of the gearbox) but definitely worth it.

[Gwynleym10]

Also if you o have the gearbox out i't may be worth reaplaceing the engine rear seal and some of the gearbox oil seals.


It is a job that you can do on axle stands, (as longs as they are set at there highest position)

Otherwise is going to be at least Ԛ£100 labour.

[cabrio327i]

Hi Pete, Andy325 is right with this one, its not the release bearing! its the gearbox internals making the noise from the input shaft spining with the engine, what gets rid of the noise or definately makes it less is a change of gearbox oil, some boxes were filled with auto trans oil dexron2 etc and with a lot of miles on its too thin causing the geartrain to rattle, change the oil to EP80w90 and it should be lots better. cheers Dave

[Jimbob]

Gearbox internals as I've been told by MANY people, I have the same prob. It's nothing to worry about and I've heard that even a rebuild wouldn't sort it. Just an irritating noise (sometimes, doesnt always do it in neutral)

[E30Adam]

If you don't have a rattly gearbox on an M2 engined car then you're a very lucky person.

Nothing wrong with the 'box itself, I've known people to spend hundreds on rebuilt 'boxes only to find the noise is still there.

Everyone I know with an E30 has a rattly 'box, nothing to worry about, just annoying.

[jmc330i]

I know its difficult to judge noises on forum but, going by Petes description, its sounds exactly like the noise mine made. A grating noise when the car is at idle, that goes when you depress the clutch pedal. Mine did it for about 2 years.

The problem was the clutch release bearing...


The gearbox was fitted into another car as it came out of mine, with a new clutch and bearing and the noise was gone.

[Sooty]

Andy325i wrote

If the noise dissapears when you press the cluch pedal down it is the bearing on the input shaft to the gearbox (I.e. when you depress the cluch you disconnect the gearbox). If it made the noise when you pressed the pedal it would be the thrust bearing as this is when the thrust bearing is under load.

Sorry Andy but I think I'm going to have to disagree with you on this one

Surely the noise comes from the thrust bearing because it's worn and there is excessive play between the race bearings and their retaining cage? With no load, it can rattle around to it's hearts content.
When you press the clutch pedal, it places the bearing under load, takes up the play and the noise disappears.
This has been the case on every car I've ever heard this on for the past 30 odd years (be it F**d, V**xhall, R**er, Japanese, etc, etc).

If someone can explain different, then I'm prepared to be flamed

[LOOPYLEE1965]

:yeahthat: normally the thrust bearing mate

[Brianmoooore]

Andy325i wrote

If the noise dissapears when you press the cluch pedal down it is the bearing on the input shaft to the gearbox (I.e. when you depress the cluch you disconnect the gearbox). If it made the noise when you pressed the pedal it would be the thrust bearing as this is when the thrust bearing is under load.

Sorry Andy but I think I'm going to have to disagree with you on this one

Surely the noise comes from the thrust bearing because it's worn and there is excessive play between the race bearings and their retaining cage? With no load, it can rattle around to it's hearts content.
When you press the clutch pedal, it places the bearing under load, takes up the play and the noise disappears.
This has been the case on every car I've ever heard this on for the past 30 odd years (be it F**d, V**xhall, R**er, Japanese, etc, etc).

If someone can explain different, then I'm prepared to be flamed

You should be able to differentiate between the two by only partly depressing the clutch, so that the engine thrust bearings are under load, but the input shaft is still turning.

[Sooty]

You should be able to differentiate between the two by only partly depressing the clutch, so that the engine thrust bearings are under load, but the input shaft is still turning.

Engine thrust bearings? Aren't they on the crankshaft Brian?

I'll get me coat.

[PeteE30Tourer]

Interesting debate i've openned here! Thanks for all your comments. I'll definitely try the oil change first - at my last MoT, they said i had a bit of an oil leak from the gearbox, so perhaps it's just run dry a little. Having said that though, i'm pretty sure the clutch is worn so i may just bite the bullet and get it all changed - more bl**dy expense!!

[Adammcf]

Ive always thought it was the release bearing. It has worked on any other cars. Was going to wait until my clutch needs done as my car is making this noise as well.

[zaust]

Hi Pete, Andy325 is right with this one, its not the release bearing! its the gearbox internals making the noise from the input shaft spining with the engine, what gets rid of the noise or definately makes it less is a change of gearbox oil, some boxes were filled with auto trans oil dexron2 etc and with a lot of miles on its too thin causing the geartrain to rattle, change the oil to EP80w90 and it should be lots better. cheers Dave

this is what i call death rattle not much you can do about it. Change oil as above but the box will rattle all the same but wll still last for years and years to come..

[hogweed]

The noise I always took to be tappets or injectors on mine (that's EXACTLY what it sounds like), I suddenly realised goes away if I rest my foot on th clutch.

I took it to my local BM independent - who I trust - and they said clutch release bearing but not to worry, it's be ages before it caused problems.

But based on much previous scouring of posts about everythign on here, Mr Mooooooooooooooooooooooooooooooooooooooooooooooore seems to know what he's talking about.

[dazleeds]

:yeahthat:

[Brianmoooore]

If resting your foot very lightly on the clutch changes the noise, then it might well be the clutch release bearing. Nothing unusual in one of those failing.
The gearbox rattling happens when the car is in neutral and with the foot well away from the clutch pedal. Nothing unusual about that either, and nothing to worry about, within reason.

[Simon13]

i've told u about this i'm sure pete all M20's gearboxes do it, especially sport boxes! mine does and an oil change didn't remove the noise.

I've asked an ex-bmw master technician about this and he said it's nothing to worry about! if he says so it's good enough for me.

This question gets asked all the time!

[jamie325isport]

Its when you put your foot on the clutch and the noise gets worse is when you need to start worrying so i found. Pedal also got really heavy to push down.

[PeteE30Tourer]

Got the oil changed last night - apparently the level of oil in there was very low - i've got a leak from the rear of the box. Anyway, topping it up with fresh oil made little difference to the noise, but i'm just going to carry on driving it and see what happens.

Thanks for all your input to this.