Knocking/rubbing noise on driving/bumps

[Micro]

Hi all!

I am still investigating the knocking/rubbing noise ongoing with my Focus. It has been plaguing me now for a little while, stopping and starting again, and slowly but surely i'm ruling out causes.

It began with a "rubbing" noise on steering - at a stop or low speed, audible in the cabin when steering. Then slowly a louder knocking type noise developed when going over bumps. It does not do it all the time, occasionally it will be absolutely fine. Did think that when it was warmer outside it stopped doing it but it has since done this when it's been a sunny 15 degrees.

So far I have replaced/covered:

• Lower suspension arms (L + R). Bushes perished and excessive movement when I had them off the car.
• Anti roll bar links (L + R) - anti roll bar seemed stiff and had no excessive movement. Old anti roll bar links seemed ok - no sideways/up/down movement in the ball/socket,only a little floppy.
• Spraying silicone lube through the gap in the strut brace (kind of aiming at the top mount), silences the steering noise, but does nothing to fix the knocking noise on driving. This lasts 1 week~

In the past week, I have noticed a metallic rattle on driving / idling - similar to this: https://www.youtube.com/watch?v=5RG3-HH3KqA however it does it at idle mostly or engine under load, goes away when revved with no load, and slightly lower pitched. I think just a coincidence. 

There are NO performance issues, the car still drives fine, pulls straight, and brakes straight. I am questioning whether the strut mounts need replacing.

 

 

[Micro]

And as mysterious as it started, it's now stopped.

I had a new knocking noise start but fixed by tightening the lock nut on the passenger track rod end (had an alignment, and a recheck recently, must not have tightened it up properly), so fixed that, and then had a good push/pull/general work round all the suspension components on the front and the rear. I seem to remember the spring moving slightly on the passenger side and a click, but was unable to make it repeat that, so I am wondering whether it had worked itself out of its proper position slightly, but could be spouting broccoli.

Aside from some in/out movement of the axles (assumed normal due to its function), there is no free play in any other component aside from a slight floppy feeling to the track rod ends (but no clicking/free play in these).

Mysteriously, the car no longer bangs and rattles over bumps. It just sounds like I would expect it to sound! Still puzzled as to what it may have been.