Light knocking noise from the chassis

[TANKSLAPPER]

I would appreciate your help.

I’ve got a light knocking noise which seems to come from the front end of the car, only when it has warmed up, the hotter it gets or the longer the run the noise is louder.

I can only hear the knocking when the car is freewheeling and slowing down in a straight line from about 35mph to 5mph ie with no load

The parts I have changed to try and rectify this problem are:-

Front suspension and top mounts
Front lower wishbone and rose joints
Front lower wishbone bushes
Engine and gearbox mounts
Rear trailing arm bushes with limiter kit
Exhaust mounting rubbers
Anti Roll bar drop links

The only other things I can think of changing is the steering rack , or the rear camber arms

[SMD]

Prop Shaft?

[NZ_M3]

Describe the noise more .... i.e. is it a clanking sound? or metalic sort of a knock or a dull thud thud thud ...

It'll be a rotational related - so work from the wheels back and check every component from there on.

Given that it's not a load related noise you can rule out engine mounts and gearbox mounts.

Might be a wheel bearing, but these seem to rumble rather than knock.

[TANKSLAPPER]

Originally Posted by NZ_M3

Describe the noise more .... i.e. is it a clanking sound? or metalic sort of a knock or a dull thud thud thud ...

Thanks for your response, I don't think it is the wheel bearing as this is a problem I have had for the past 30 months, and have traveled some 20,000 + miles since it occured

The sound is mainly heard around 20 mile an hour and it is more of a bobbling/bouncing dull knocking noise, and you can feel it on the near side when free wheeling

[NZ_M3]

Check your tyres ... sounds like there's a flat spot on one of the tyres.

[TANKSLAPPER]

Originally Posted by NZ_M3

Check your tyres ... sounds like there's a flat spot on one of the tyres.

No its not that, I had four set of tyres since the noise begun

Any chance you could record the noise on your mobile phone and post it? Might give us a better idea.

[bryce]

Originally Posted by TANKSLAPPER

The sound is mainly heard around 20 mile an hour and it is more of a bobbling/bouncing dull knocking noise, and you can feel it on the near side when free wheeling

Does it do it if the car is out of gear? are you familiar with the knocking noise you get with SMG at lower speeds?

Video / sound clip would be good buts its always hard to capture these noises.

[TANKSLAPPER]

Originally Posted by Steve Gill

Any chance you could record the noise on your mobile phone and post it? Might give us a better idea.

Hi, I can just see me hanging the missus out the side window by her legs whilst recoding the noise. LOL Nice one

Unfortunately the noise isn't to loud and it only does it for a 5 to 10 seconds

Simon Hill reckon it could be the brake pads

Thinking back, it was the time I fitted the ap's on.

I jacked the car up today and when I turn the wheels back and forth you hear a light clonking noise. Also the calipers being aluminum they would expand more as they became hotter.

I will go out later for a test drive and see if the noise stops when I brake.

[bryce]

Originally Posted by TANKSLAPPER

Simon Hill reckon it could be the brake pads

Thinking back, it was the time I fitted the ap's on.

Think Simons got it for you... Mark_CSL's car does this too cos he's got floating calipers on the rear (not APs, but bigger ones).

He'll be along shortly Im sure...