Front Knock/clunk Under Brakes After Driving A While

[Spoony]

I've got an annoying 'clunk/knock' seemingly more from the centre of the car (front) on braking. Initial very light braking (so pads engaged) will not make it happen, it takes a tad more than that. It can be done forward and reverse. BFii XR6T

It doesn't happen on initial driving, takes maybe 5-8kms to start hearing it.

I did have a similar noise on corners mainly, turned out to be LHS engine mount wasn't 100% tight. That's fixed and thinking along the same lines I've ensure the RHS mount is FT. Both mounts are less than 30,000km and genuine.

The car has most bushes new and super pro, only link pin front swaybars and tie rods are original. But as it spent a day a Fulcrum to find the other noise (LHS mount) every thing on the suspension has been checked and tightened 1000 times now.

Just wondering what area/items would only cause a 'clunk' under brakes in either direction. I've check the brakes, 99% it's not there, I can hear the noise beside the car walking along it, like being in the car, it sounds deeper than out on the wheels.

Something that need the car to be driven for a bit to 'appear'. I idled it for 30mins this morning, so the engine side of things was well warm, but still, it took a decent amount of driving to get it 'clunk', which to me says not engine mount etc.

It's 100% solid and quiet over bumps and in turns. I've tried to use the hand brake (sucks on these cars) to replicate the weight shift and it seems clunk only happens with normal brakes.

Most annoying as with everything fresh as (Superpro everything), the bilstiens etc the car rides and feels better than the bosses less than 1 year old G6E Turbo despite it being 07 and 215,000km, so this noise is really annoying.

Cheers

[Pete A]

Maybe drive shaft. If it does it forward and backward. If you have an auto. Stall the car up in R and D to about 2000 RPM and you may hear the noise.

[Spoony]

It's 100% in the front of the car, not the rear. It seems engine load makes no difference. Ie I can stall up against the brakes either way. It only occurs when rolling (even slowly) and the brake are applied a reasonable amount. When you then accelerate and move again it's reset and the noise will occur again. If you roll then brake a bit 'clunk', then keep decelerating (off the brakes) then brake again it wont always do it again until getting back on the throttle.

[Wenier]

Is it the brake pads knocking around with the disc?

I had similar in my subie and it was the stainless retainers had lost their spring and allow the small movement of the pad and made the knocking while going along. Wasn't all the time either.

[discostig]

Something in the engine bay moving forward and hitting metal? Something not bolted down properly? Thinking outside the box a little but you never know. Spanner left there?

[Ralph Wiggum]

Did you have the ball joints replaced?

[Spoony]

Good ideas. Have messed with the brakes. Played with the retaining clips and also put some anti seize behind the pads, cleaned and greased up the slide pins etc, made zero difference.

All suspension inc ball joints is completely new front and rear apart front sway bar link pins and tie rod ends (all apparently OK according to Fulcrum).

I was thinking something 'moving' and clunking but wonder why it only happens after driving 7+ kms or so to start hearing it, then it gets worse over the next 5 kms. It really sounds to me like something is re positioning and going backwards and forwards on the spot using the brakes in either direction can achieve the same thing.

What items would need 'use' or warm up to start doing something like this in the suspension/brakes. The sound can sort of move across the front of the car a bit too, ie it doesnt' sound 100% placed in the same spot but is definately 'inbound' of the wheels when heard from outside the car.

At the moment stereo up is the fix haha (though have noticed I can still 'feel' it at times)

Edited 23/01/14 09:40 PM by Spoony