Hi

I have a rumbling/vibation/rattle noise coming from, what appears to be the underneath of the car, the rear passenger side. 

I have, however, opened the bonnet and the noise appears to come from the fan belt area.

The noise can only be heard when the engine is revved at less than 2000 revs. Over 2000 rpm it can't be heard. More audible in cold weather.

I've brought to a mechanic and he confirmed that the noise in coming from the fan belt area, but he's not exactly sure what it is without stripping it down.

Anyone else experienced anything silimar? 

Thanks.

Hello Gareth,

Any such noise must be considered serious, either in terms of the current cause, or the potential for catastrophic failure of another component . 

If this were mine, I would be getting the auxiliary belt removed as a matter of urgency, to see if this influences or eliminated the noise. Further, I would not be using this until this issue is sorted. 

Kind regards,

Gareth. 

On 1/31/2021 at 8:32 AM, Magnet said:

Hello Gareth,

Any such noise must be considered serious, either in terms of the current cause, or the potential for catastrophic failure of another component . 

If this were mine, I would be getting the auxiliary belt removed as a matter of urgency, to see if this influences or eliminated the noise. Further, I would not be using this until this issue is sorted. 

Kind regards,

Gareth. 

Hi, the man is right if the belt becomes damaged it can potentially get bits of debris into the lower part of the cam belt drive, game over, I think there are only three main suspects, 1, the auxiliary belt tensioner, this can be checked by observing the pulley whilst at idle and then turning on every electrical service available, aircon, lights, blower motor, if it starts moving thats your kiddie the motion of the jockey wheel should be uniform and level regardless of load.

2, the aircon clutch bearing, run the engine then turn on the aircon if the noise ceases then you have your answer, it's the electromagnetic clutch engagement that takes up any slack in the bearing.

3, the free wheeling clutch on the alternator this can be tested by removing the belt and running the engine.

I wish you luck.

Many thanks lads

Let us know how you get on Gareth.