Throwout bearing or input shaft bearing?

[JarHeadP]

Hi all,
So my ibiza has developed a strange knocking kind of noise when the car is in neutral with the clutch up, but as soon as i push the clutch pedal the noise goes away, also when you rev the car the noise turns into a sort of whirring sound but im guessing thats just because the its rotating faster so it sounds a bit different.

Another scenario when i hear this noise is when i downshift mainly from third to second, when i put it into gear when the clutch is still pushed down the whirring sound comes back again but slows down as the car slows down, you cant really hear it once the clutch is up and the gear is engaged but that maybe just because the sound of the engine is overpowering it. You can also hear it when the car is creeping maybe around 10mph when slowing down and i put it into first.

It's the 1.4 100hp model and has 56'000 miles on it (Still disappointed that I'm having a gearbox problem like this at that kind of mileage )

Pretty sure its the input shaft bearing after a bit of googling but a few forums have suggested throwout bearing too so thought i'd see if anyone else on here could confirm, also if it is one of these bearing would it be cheaper to just buy a new box and have it fitted than to get the bearing replaced?

Thanks in advance

 

[Arkaig]

Basically if it makes the noise with the clutch pedal up, it's the ISB or something in the gearbox.

If it makes it with the clutch down, it's the throwout bearing. Sometimes a clattering with the pedal down can also be the flywheel as if the dampeners are gone the plates will smash together with each engine power stroke.

Really unusual for these boxes to have symptoms at such a low mileage though. I'd first of all make sure there is enough oil in the box! Low oil can cause all sorts of noises as some of the bearings will be drying out.

There's no cheap fix for the ISB, but some recommend an oil additive which can sometimes quieten down the bearings. I tried this in my Vivaro van (which DOES have a knackered ISB) and it made a small difference, but it's just delaying the inevitable.

 

[Arkaig]

I seem to remember the boxes in these cars are fairly easy to get out so maybe it will cost less than you think to get it refurbished. If you can get it out yourself and take it to a specialist you will save even more.

The ISB can be done DIY if you have some bearing pullers and slide hammers but I've never seen inside a VAG box so I can't advise further.