Knocking which varies with speed - Suggestions please.

[corradophil 3]

Last night when I was going out I noticed a slight knocking for about 10 seconds, this happened whilst going in a straight line doing about 25mph.

 

It stopped and did not happen again until I was coming home after having covered around 20 miles. This time I was doing about 60mph and it was more severe.

 

Today it did not do it at all until later on tonight when it did it again for few seconds at various random times. It changes with road speead, it is unaffected by what gear you are in including neutral.

 

My first thoughts were, is it the torsional damper weight on the O/S driveshaft come loose and moving around on the shaft, sometimes catching something, but I had a quick look and it is not this.

 

It is similar to the sound you get from the exhaust hitting the underneath of the car, but the exhaust is all secure, plus I've never experienced a knocking exhaust which is directly effected by road speed.

 

I reset all the engine mount positions at the weekend, but I am 100% possitive all the bolts are tight, I will inspect to see if the engine is catching on anything as a result of this, although again I can't see it being so directly related to road speed.

 

All CV gaitors are fine and there is no knocking on lock like you usually get with warn joints, and you can feel this through the floor of the car, almost like someone hitting it with a hammer.

 

So before I get underneath it on Saturday to find out what is wrong, any suggestions of things I've not covered would be very useful.

[Blue_Joe 0]

Driveshaft weight come loose??

[iow_corrado_g60 0]

My first thoughts were, is it the torsional damper weight on the O/S driveshaft come loose and moving around on the shaft, sometimes catching something, but I had a quick look and it is not this.

 

 

what is this please?

[corradophil 3]

what is this please?

 

A rubber donut on the O/S (longest) driveshaft only.

 

After driving to work this morning I am 99.9% sure it is one of the CV joints on the O/S drive shaft.

[ben16v 0]

A rubber donut on the O/S (longest) driveshaft only.

 

 

sorry to hijack, my one of these came loose yesterday was banging about, just grinded it off.... is that ok? :lol:

[corradophil 3]

sorry to hijack, my one of these came loose yesterday was banging about, just grinded it off.... is that ok?

 

I doubt you'll notice any difference, but VW did fit them for a reason.