Amazon, 2.2, Auto, transmission noise?

[apc]

Amazon, 4.2 TDi, Auto, 1998, 100 series, 105K miles.

I have a noise which suddenly appeared which appears to originate from the transmission. The noce is not present if I rev the engine in neutral, and it occurs before the turbo spools up.

It is never easy to descibe a noise, but the basically it sounds as if something is "loose" - a sort of bearing sound - which increases with speed.

There are no warning lights and the car seems to be performing as usual, although obviously I have not pushed it.

Any ideas what this could be? I would sooner troubleshoot it before something potentially fails.

Thanks very much.

 

[Jon Wildsmith]

Does the sound vary with speed, does it change depending if you're on the throttle, coasting or engine braking and does it change if you put the gearbox into neutral while moving?

 

[apc]

Does the sound vary with speed, does it change depending if you're on the throttle, coasting or engine braking and does it change if you put the gearbox into neutral while moving?

I would say that the primary factor is throttle, and then resultant road speed.

If the car is in neutral and I rev the engine, the noise is not there.

Once the car is moving, and I take my foot off the throttle, the noise slows, independant of road speed.

Thanks.

 

[frank rabbets]

I have a slight metalic vibration noise on mine under the circumstances you describe. Another one I test drove had the same. It is very slight and sometimes I don't hear it for a day or so.

Frank

 

[Graham]

Does the sound vary with speed, does it change depending if you're on the throttle, coasting or engine braking and does it change if you put the gearbox into neutral while moving?

I would say that the primary factor is throttle, and then resultant road speed.

If the car is in neutral and I rev the engine, the noise is not there.

Once the car is moving, and I take my foot off the throttle, the noise slows, independant of road speed.

Thanks.

.
A differential bearing, hub bearing ?

Gra

 

[Jon Wildsmith]

From the description it isn't road speed related as a diff or hub bearing would be, sounds like it's engine speed related so engine or gearbox input area which makes it hard to think of any suggestions as to what it might be or how to diagnose it further

 

[apc]

From the description it isn't road speed related as a diff or hub bearing would be, sounds like it's engine speed related so engine or gearbox input area which makes it hard to think of any suggestions as to what it might be or how to diagnose it further

Thanks for your suggestions so far.

I have been carefully listening to the noise over the last couple of days, and I can say that that it appears to be more noisy under engine load.

If I am gentle on the accelerator, it is hardly noticeable, but if I if I give it more acclerator it becomes highly noticable.

One thought that it could be the Turbo, but then again, the noice is not present if the engine is revved while out of gear. Could the turbo only make the noice under load, independant of engine revs?

I know this is not easy to diagnose on a forum, but I don't want to have to pay a workshop to take things to pieces in the hope of finding something

This is a new one on me - had the vehicle for 14 years this month - so I would like to at least narrow it down.

Thanks again.

 

[Jon Wildsmith]

Does the slowing of the noise lag behind engine speed? A turbo lags behind engine RPM a bit, so you can usually hear them slowing down, but the bits in your gearbox that turn with the engine will be matching engine speed without any lag. How's your exhaust front pipe especially by the flexy section behind the front wheel? Even a small hole that doesn't sound blowy at all can mean you suddenly hear the turbo spinning much louder than usual.

How about trying to describe the nature of the sound itself as well

 

[apc]

Does the slowing of the noise lag behind engine speed? A turbo lags behind engine RPM a bit, so you can usually hear them slowing down, but the bits in your gearbox that turn with the engine will be matching engine speed without any lag. How's your exhaust front pipe especially by the flexy section behind the front wheel? Even a small hole that doesn't sound blowy at all can mean you suddenly hear the turbo spinning much louder than usual.

How about trying to describe the nature of the sound itself as well

First - I typoed the Subject - the vehicle is of course an Amazon Land Cruiser VX 4.2 TDi, Auto, 100 Series.

I will take it out for a spin and listen carefully. It is more noticeble when the engine warms up.

It passed it's MOT last week, so I would assume that any exhuast issues would have been picked up.