A strange knock/ crack/ tap noise

[Mr2paul]

Hi all, I hope your doing well.
The car drives fine but under braking which can be hard or soft the front offside makes this noise, only once then for a split second and no noise until the next time I use brakes. The wheels are all secure as well as brakes so I'll need to look further v soon. Could it be suspension, brakes or something more sinister ? Thanks in advance.

[Dev]

I would go over all of the control arm bolts and tighten them down. I would also inspect all of the bushings by pulling back and forth on all arms, sway bars, wheels and axles. Rule this out first. 

[Mr2paul]

Thx Dev, I'll look at that. It's strange how it's a one off knock only under braking and once it happens then all is quiet. Good call tho, I can see some logic to this.

[shnazzle]

Thx Dev, I'll look at that. It's strange how it's a one off knock only under braking and once it happens then all is quiet. Good call tho, I can see some logic to this.

I had this. It was exactly as Dev said. A bolt that seemed tight, once I tightened it more the knocking stopped. It was on the trailing arm

[Mr2paul]

Thx for that. Was it actually loose ?

[shnazzle]

Thx for that. Was it actually loose ?

Yes and no. It felt right, but obviously not tight enough! 

It didn't jiggle when I tried to move it by hand. But with the momentum of the car behind it, it did a "clunk" when I braked. And not all the time. 
I found I could tighten the bolt another quarter turn and that did thr trick

[Mr2paul]

Great call guys, I'm sure your both correct, as I was having my doubts about brakes and now having given it thought all makes sense. Thankyou.

[Carolyn]

While I'm not the world's biggest fan of 'use a torque wrench on everything', suspension is one place where it's a damn fine idea.

PM me with your email, and I'll send the torque specs.

[Dev]

Thx Dev, I'll look at that. It's strange how it's a one off knock only under braking and once it happens then all is quiet. Good call tho, I can see some logic to this.

I had this. It was exactly as Dev said. A bolt that seemed tight, once I tightened it more the knocking stopped. It was on the trailing arm

 Some of these bolts become corroded shut and others walk in time with vibration.  I use light thread locker now which is also good for some rust prevention.
  It generally starts out as intermittent and then you hear it all the time if it is in fact the control arm nuts.
 Other sources is a slightly loose top mount and misaligned brake pads where they were not sized correctly  that tends to shift and knock when the pedal is first pressed.
 I had all of these scenarios play out at one or more times in my ownership. 
 Most of the time you can push the car with your whole body rocking it back and forth to reproduce the sound.

  If all else fails and you cant find the noise take it to a qualified mechanic or wait for it to get louder so its can be found.

[Mikeymead]

Just to add to the confusion I had a very similar noise to this which turned out to be front pads that where a bit loose in the carriers. They would move vertically and knock when the brakes were applied.

[LeRich]

I had this same issue once.... turned out the wheel nuts were loose :S

[Mr2paul]

Thankyou all, iv had a loose wheel once and it was a knock that was constant , related to speed. It could be brake pads shifting but I'm doubting as its quiet load but of coarse I will check in a few hrs after some shut eye. Whatever it takes to sort will get done. I'm already planning on swapping wishbones which I already have, arb bushes, drop links as a matter of coarse and possibly shocks n springs if the prove to be past it. They look ok and an enthusiast owned it a while back so I haven't had any shocks yet.mi will update with any info as soon as I no.

Also thanks to Carolyn for the torque settings although I did think I would shear off the top mounts, but all was ok, as a side issue, do you think adding the strut brace has highlighted a problem with the car, just a thought, if it has then that's a good thing right?

I'll post a topic of things iv done in my 600ml of ownership, non of which were urgent, but needed attention and so far it's been fun .
It may help a new owner so you experts and racers , look away now.

[scm2004red]

I can still recall the same issue a friend of mine had, defeated all attempts to find it until I went out with him one day and removed a golf ball from the passenger side pocket, cured problem immediately..

[virginpaul]

Sounds like a result of compression of a strut.  Brake - nose dives - clunk.... question is, does it knock again after a brake application on acceleration
 - nose rises - strut extends?.