Hi,

 

I have a 2005 1.9 TDi Fabia with 233,000 on the clock. For a while now I've been getting a rhythmic repetitive knock from the transmission whenever the load is lightened on the front of the car - going over the brow of a hill at speed for example. The repetition rate of the noise is realted to road speed and aproximates to the wheel rotational speed.

 

With a passenger on board it does not happen - I assume the load on the front end is enough to keep the car sat down on the road.

 

It can also be induced by taking a roundabout at speed.

 

In the last 18 months it has had new gearbox bearings, clutch, engine mounts and wishbone rear mounts. 

 

I have my suspicions but am keeping an open mind in case anyone here has direct experience of this problem and its cure?

 

If that is you I'd be pleased to hear from you, thanks in advance.

Have you checked the consul bushes?

 

SN

Hi Steve,

 

Thanks for your response - I'm afraid I don't know what or where the consul bushes are or what they do. The knocking noise is relative to the speed of wheel rotation and sounds or seems transmission related.

 

Rergards, RB

Hi Steve,

 

Thanks for your response - I'm afraid I don't know what or where the consul bushes are or what they do. The knocking noise is relative to the speed of wheel rotation and sounds or seems transmission related.

 

Rergards, RB

CV joint,maybe ? or lower wishbone bush ?

Hi Steve,

Thanks for your response - I'm afraid I don't know what or where the consul bushes are or what they do. The knocking noise is relative to the speed of wheel rotation and sounds or seems transmission related.

Rergards, RB

Have you tried jacking up front and checking for signs of faulty wheel bearings.

Does the sound become clearer when clutch is engaged.

Have you had gearbox oil replaced lately

Also could be to do with tread pattern of tyres if you get me

Edited 22 April, 201511 yr by vzo25

To me it would be a whine if the gear box was faulty, or a grinding/clunking.  If it is a "rolling" knock, a rumble, then it could be gear box. But I'd expect it to be there at most speeds and not related to weight.

I'd go for wheel bearings/ball joints/steering rack/wishbones/etc..

Going round a roundabout suggests noise on right hand bends. I there noise on left hand bends?  If not wheel bearing on left side or possibly drive shaft CV joint.

Thanks all,

 

First just like to say thanks for your suggestions.

 

It is a 'rolling' knock as Oomer describes it, definitely related to road speed and load on front wheels. I haven't been able to check on left hand bends, I can't find anywhere round here with enough room to drive fast, tight, left hand turns. I'll keep looking. But I don't think gearbox as it was rebuilt 18 months ago with a new clutch. I should add it is there on a very light throttle, just coming on and off the gas, a touch of throttle it is there, ease off and it is gone.

 

I'll see if I can get the wheel bearings and drive shafts checked, or maybe just dispose of it with 233,000 on the clock.

 

Thanks again,

RB.