NSF knocking, what is it??

[Tedswagon]

Hi all,

typically my car has developed a knocking sound after the wife had it for the day, it also developed an empty fuel tank and was covered in muck The second two problems I have since fixed!

The knocking is when there is any movement in the front wheel up or down. I have taken the wheel off, car on stands, jacked up the bottom of the strut (only a pump or two of the jack before the health and safety crew say anything). Any movement to compress the shock gave a clunk. I held the drop link as I did this and could feel the vibration of the clunk but it was stronger when I held the underside of the control arm. I think it is the centre ball joint of the control arm but it is new - only on the car for a couple of thousand miles at the most! All of the ball joint have no signs of leaking and all of the suspension is relatively new build. 1 year old at the most.

Any ideas what it could be?

[hezicar]

I've recently replaced all the anti roll bar links at the front including bolts and bracket with BMW OEM one which has finally sorted the clunking from the front suspension on mine. Worth starting there.....

[magpie]

top mount Ronan?

[Tedswagon]

Mike the top mounts are from BMW and only 8 months old max. But that is what I thought it was when I heard the noise first from inside the car.

Drop links and brackets, ARB bushes are all BMW and about 12 months old. Control arm is ECP (Lemforder) is about 8 months old. Eccentric bushes from BMW fitted at the time of the control arms.

Shocks and springs are from a sport and came from BBB so good quality second hand parts I'd say fitted 12 months ago. Drop of about 15 / 20mm so it's not like its rubbing the deck!

Because of the age of all the parts Im puzzled what it could be.

TBH I'm worried because I went cheap on the control arms (Lemforder) am I now paying the price!

[Tedswagon]

There is a very slight pull to the left when up above 50mph - not sure that might be something to do with it!

[pac1982]

I had a knocking noise on mine, started by replacing all the ARB bits and bobs, knocking was still there, then i replaced all the suspension tops mounts etc etc, knocking was still there so i fianlly replaced the a arms ball joints bushes etc which fixed the problem turned out it was the ball joints in the a arms

[BadDave]

Ronan

Have you tried applying some leverage to the ball joints to check for wear?
Is there vibration under braking??

[Brianmoooore]

Check that the damper retaining nut at the top of the strut tube, inside the spring hasn't worked loose.

[Tedswagon]

Dave, I used a jack under the strut to move the control arm up and down at the end and I tried to move the control arm but it seamed tight. I didn't lever it tho. Will try that this evening.

Brian, I checked the retaining nut when I did an inspection on Friday and it is still as tight. I only looked at the spring and it looked fine. The clunking did sound like it was coming from the bottom of the strut / control arm area!

I have been round the circuit at Knockhill a for a couple of dozen laps recently which will no doubt have put more load through the entire suspension but I would expect the older parts like rear sub frame or bearings to be showing signs of ware, not relatively new parts!!

[daimlerman]

Pleased that it's not just my wife that brings the things home filthy and low on fuel....the number of times I have fallen for the line,'You can use my car tonight,darrrling...'
If the top nut on the strut is tight,and the three that hold the strut to the car,I would suspect the top mount next.