Front Suspension Noise Over Speed Bumps

trten13 · October 30, 2006

I bought a new RX 400h model '06 last summer and it is making a knocking noise (only once) when driving over large speed bumps with about 25 mph. The noise started from day one, it comes from the front and it does it only when the suspension is compressed after leaving the bump (not when first hitting it). The dealer changed the front shock absorbers and bushes of the anti roll bar but the problem is not solved. Could it be something else making this noise? Has anyone else experienced something similar?

chips229 · October 30, 2006

Hi,

I think you mean uncompressing from how ive read it.

It might be the top mount/s of the suspension knocking as they move back into place.

T7RY B · October 30, 2006

Definitely top mount.

I had to have one of mine changed.

They thought it was the drop link at first.

Should still be under warranty shouldn't it?

Not a long job 2 hours max.

GlynnB · October 31, 2006

Don't know if I can do one of these link things but we raised this here. Definitely not wear of components.

http://www.lexusownersclub.co.uk/forum/ind...c=17753&hl=

trten13 · October 31, 2006

B)-->

QUOTE(T7RY B @ Oct 31 2006, 01:23 AM) ←

Definitely top mount.

I had to have one of mine changed.

They thought it was the drop link at first.

Should still be under warranty shouldn't it?

Not a long job 2 hours max.

Thank you very much for your replies.

Yes, the car is new and we get 6 years warranty in Greece. The noise is as if something is hitting somewhere, not very loud, only once per direction of suspension move. It appears to be during compressing rather than uncopressing. Could it be something else touching somewhere? Given the reliability of Lexus it is hard to start taking the car to the dealer for trial and error solutions on a new car. I am dissapointed.

Shahed · September 18, 2007

Definitely top mount.
I had to have one of mine changed.

They thought it was the drop link at first.

Should still be under warranty shouldn't it?

Not a long job 2 hours max.

I bought a 2005 Rx300. Recently had a LPG kit fitted, runs fine. However, I have started to notice a knocking noise from beneath my car, kinda coming from the back or centre. At forst I thought it might be the lpg tank (located beneath) or loose fittings in the boot however, after trying to locate the problem, I do not seem to be able to find the problem?

Anyone have any ideas? Again, only noticeable when drvign over potholes or coming off speed-humps etc.