My XJ8 seems to like making noises. Sway bar bushings replaced front shocks replaced, front shock upper mount rubbers replaced and things were quiet for a while and now something new.
When cold there is a clonking sound from both left and right side front. Something like the hood latches not being engaged and the hood moving up and down. I actually adjusted the hood latches even though they looked perfectly fine.
The sound goes away when the engine gets hot ?????

 

Hi ho Aregg,

If the “clonk” sound was not apparent before all your work mentioned in your post and it is there now; I would suggest backtracking each item you replaced or adjusted to find the culprit.

 

Interestingly enough, I have the same problem. New sway bar bushings, shocks all corners, new upper shock bushing (neoprene), drag links, silicon spray on the rear exhaust hangers, and quiet as church on Sunday. Except when it gets really cold out, then a clunking begins, both sides but louder on the right. Underneath, I retightened everything; sprayed silicon on all the rubber mounts, can't shut it up. Quiet above 50*F; noisy and getting noisier as temp drops to or below freezing. Heard it last Winter and again this one.

Frustrated, I take it to my local indy (Abacus in VA Beach).

Tech determines the clunking is coming from the upper shock mounts. Appears as it gets cold the neoprene in the new mount hardens and shrinks and allows the shock rod to bang around. They shimmed it (I have yet to take the upper bolt off to see what that shim looks like), 80% of the cold clanking gone!!

Remaining noise silenced by tightening the tension on the hood (bonnet) when locked.

Now only noise comes from rear exhaust hangers (ordering those for early switch come Spring).

 

Sir Jagness the work was done well before the cold spell and all was fine.

Jhartz Now that you mentioned it I am pretty sure it is the neoprene upper shock mount. If I turn the car on and leave it to warm up no noise at all. I wonder if in fact they used a shim or a larger washer that will compress the bushing more.