Mysterious Front End Noise

[Funollie83]

I've searched through the forums and not been able to anyone who has had the same issue.

 

Car in question -

 

2004 4.5 Cayenne S UK Spec 143k

 

Symptoms -

 

Intermittent! 

 

When crawling in traffic between 10 - 20mph there is an occasional rotating noise (similar to a dry bearing) with a clunk on what seems every rotation?

Step on the accelerator and the noise accelerates with the speed of the vehicle. Sometimes getting louder, eventually ending with a clunk that seems like whatever it is has located?!

Also possible on occasion to get rid of the noise by shaking the steering wheel side to side OR using the brakes? 

Does not seem related to engine speed. 

Took the car to the top of a hill and put it in neutral before rolling down and did not get the noise - however as it is intermittent I cannot be sure!

 

Cures attempted thus far  -

 

I have taken it to a independent mechanic who test drove it and the noise did not make itself apparent, he also put it on the ramp and could not find anything loose or obviously about to fail. 

Checked PAS fluid, was quite low, topped up with fresh fluid doesn't seem to have dropped in the last couple of weeks.

 

 

Any advice gratefully received.

[lewisweller]

1 hour ago, Funollie83 said:

I've searched through the forums and not been able to anyone who has had the same issue.

 

Car in question -

 

2004 4.5 Cayenne S UK Spec 143k

 

Symptoms -

 

Intermittent! 

 

When crawling in traffic between 10 - 20mph there is an occasional rotating noise (similar to a dry bearing) with a clunk on what seems every rotation?

Step on the accelerator and the noise accelerates with the speed of the vehicle. Sometimes getting louder, eventually ending with a clunk that seems like whatever it is has located?!

Also possible on occasion to get rid of the noise by shaking the steering wheel side to side OR using the brakes? 

Does not seem related to engine speed. 

Took the car to the top of a hill and put it in neutral before rolling down and did not get the noise - however as it is intermittent I cannot be sure!

 

Cures attempted thus far  -

 

I have taken it to a independent mechanic who test drove it and the noise did not make itself apparent, he also put it on the ramp and could not find anything loose or obviously about to fail. 

Checked PAS fluid, was quite low, topped up with fresh fluid doesn't seem to have dropped in the last couple of weeks.

 

 

Any advice gratefully received.

If shaking steering wheel or braking makes it go away then sound like pad on disc touching an edge, worn caliper bushings, backing plate cover rubbing. But a clunk in the mix doesnt sound like brakes to me. That's more likely a CV joint or front diff. A worn wheel bearing clunking would at low speed would be a very bad noise at higher speeds cornering under load etc. 

Start with brakes, get the noise going and don't steer or accelerate just very light touch the brake so vehicle speed does not really decrease but pads and disc make contact if noise stops you got your way forward. 

 

[Funollie83]

1 hour ago, lewisweller said:

If shaking steering wheel or braking makes it go away then sound like pad on disc touching an edge, worn caliper bushings, backing plate cover rubbing. But a clunk in the mix doesnt sound like brakes to me. That's more likely a CV joint or front diff. A worn wheel bearing clunking would at low speed would be a very bad noise at higher speeds cornering under load etc. 

Start with brakes, get the noise going and don't steer or accelerate just very light touch the brake so vehicle speed does not really decrease but pads and disc make contact if noise stops you got your way forward. 

 

Thanks Lewis, I will try this first and report back.

[Funollie83]

On ‎11‎/‎10‎/‎2016 at 1:49 PM, lewisweller said:

If shaking steering wheel or braking makes it go away then sound like pad on disc touching an edge, worn caliper bushings, backing plate cover rubbing. But a clunk in the mix doesnt sound like brakes to me. That's more likely a CV joint or front diff. A worn wheel bearing clunking would at low speed would be a very bad noise at higher speeds cornering under load etc. 

Start with brakes, get the noise going and don't steer or accelerate just very light touch the brake so vehicle speed does not really decrease but pads and disc make contact if noise stops you got your way forward. 

 

 

With reference to the above, I can confirm that tapping the brakes does not stop the noise at all. Coming to a complete stop and starting again did though?

Any further suggestions now that the brakes have been eliminated are most welcome!

 

[lewisweller]

3 hours ago, Funollie83 said:

 

With reference to the above, I can confirm that tapping the brakes does not stop the noise at all. Coming to a complete stop and starting again did though?

Any further suggestions now that the brakes have been eliminated are most welcome!

 

So assuming it is rotating and the noise increase and decreased per revolution? It got to be CV or front diff I think. By hand check the CV for back lash movement and in out movement play. The diff is harder to check.