Knocking... Again!

[Pointer772001]

Hi Everyone,

I'm sorry to post yet another "knocking" topic but mine is getting quite bad (and annoying)

I have taken it in to my usual local garage who are brilliant but they say they cant find anything wrong, it happens at mainly low speeds over minor bumps and speed humps but hardly hear it when travelling above say 40 mph.

I looked at the previous service history and did find on one of the servicing sheets "could be top mounts" but these seem fine....

Does anyone have any ideas? is it a cheapish fix? its a shame as the rest of the car is so quiet, its only done 50,000 miles so its almost perfect mechanically apart from this of course lol

[lexus22]

Safe bet it's a shock giving the knocking sound over bumps, not a cheap fix though.

[smegyboy]

Hello I've had a similar problem and recently got to the bottom of it so this might help.

Had a couple of knocking noises from the front of my is200 kept checking bushes , abs drop links etc found nothing as worn as the knock but replaced bottom ball joint on one side and a top on the other helped slightly but knock still there . Car went for its mot i said to the guy I was hearing a knock if he could pin point it for me , he found nothing .

Finally the other day I worked out that when it was knocking and I applied the brakes slightly the knocking went away , so ordered a set of from brake caliper pins/slide and should arrive tomorrow will keep you posted .

Sent from my Iphone using Lexus OC

[hmoves]

Hi,

I had the "knock" for a while, checked and re-checked the front suspension; including dismantling everything and testing/inspecting all bushes, brakes, drop links and ball joints.

I think I've found my problem:

The shock strut lower bush bolt bushing was not centred in the bush. Over time, the upper rubber part of the bush had become soft and cracked, permitting the bushing to move and touch (knock on) the upper edges of the bush when there were sudden suspension movements (the weight of the vehicle on the shock strut loads the lower strut bush so that the bushing (bolt) takes the weight, forcing the bushing upwards, via the lower suspension arm, as shock strut/ bush is forced down.

Without removing and inspecting the shock absorber's lower bush, it would was impossible to detect as there was no visible play, noise or damage.

Hope this helps someone. I would add a diagram/photo but I can't find how.