Odd knocking. One day it will, one day it wont.

[MB-BTurbo]

I have a knocking the from the front left when going over bumps but it isnt consistent. One day it will be very obvious the next it wont be present at all. One time I thought the wheel was about to fall off, the noise was so awful but then got better. There doesnt seem to be any pattern with weather either.

Initial thoughts were the ARB bush as the other side as recently been replace and that sounded similar but knocked all the time. Any ideas as to what it might be and whats causing it to be so irregular?

 

[GP801]

Antiroll bar drop links? Have had this on various cars in the past. Really annoying and often not obvious when the mechanic checks the suspension.

 

[Tinkerer]

+1 ^^ I could not see any obvious wear on the old ones that I took off but they did cure the problem completely.

 

[Jane270ML]

+2 ^^ I've also had this on previous cars - mainly BMW's, thing is you can only really check them for wear with the wheel off the ground, releasing the load on the ARB drop link.
Look for rust around the ARB drop link ball joints.

 

[GP801]

+2 ^^ I've also had this on previous cars - mainly BMW's, thing is you can only really check them for wear with the wheel off the ground, releasing the load on the ARB drop link.
Look for rust around the ARB drop link ball joints.

Strangely enough mine were on BMWs too. An E30 and an E36. Also on a VW polo but so far never on a Mercedes.