francis123

Hello,

does somebody have an idea what the defective part could be? GS300 has run 90.000km, sound can be recognized by passing for example gullys or small bumps with speed of ~20km/h. Increasing speed let the sound disappaer. I have already replaced stabilizer bar bushes, link assy and lower ball joint assy.

Attached a linked sound file, maybe somebody is familiar with this issue.

http://www.ewetel.net/~frank.strehma...seite_vorn.mp3

Regards

sngk0250

I have the exact same problem, its driving me crazy, someone said stabilizer links, some else said it might be a shield over your catz, I'm not sure what it is but its really annoying. hopefully someone has an answer.

XxGoKoUxX

I really never had that.... That sounds soo weird, it's soo quiet in your car, and with that noise, it sounds like a mimicking ghost noise. LOL....

Have you tried the dealer?

francis123

Definetly it's not a "ghost noise", it's sounds if there is something loose in the suspension. Dealer checked, couldn't find anything. Proposed to replace one part after another, to find the root cause...very trustful....

XxGoKoUxX

*sigh* typical dealer mentality...

XxGoKoUxX

jack that side up and wobble ur wheel back and forth, see if there is movement.

EDIT: Might be your struts too. Did lexus offer to change the struts?

francis123

Did this more than one time...no movements, no sounds. Car dealer did not sepcify what to replace, at first they want to have the car in their hands and all whats in my wallet...

Struts means shock absorbers?

Cheesaleo

Sounds like it could very be a shock or shock mount going bad... I had that in my 2005 LS430 right before I replaced most of the suspension. My sense of that noise was right around when I was at 105,000 miles... I also hear about to begin in my 08’ GS460 and it also has 111,000... No doubt Lexus makes the best reliable and dependable rear wheel drive known to mankind.

chuckGS350

Sounds like a bad tire.

francis123

Definitely not, as it is noticeable using summer and winter tyres...ordered new strut mounts and struts, let see, whether it disappaered after replacement.

Kuleaze

I couldn't open the sound file, but I had a loud knock on my car several months ago, I took it to a friend's shop and put it on the lift. Turns out it was a bad muffler mount which was allowing the muffler to hit the bottom of the vehicle. I replaced it and that solved the issue.

Might not be your problem, but thought I'd offer something different than what everyone else was suggesting.

francis123

Sound file is still available.

On next weekend strut mounts + struts will be replaced, let's see!

francis123

Struts and mounts were substituted --> sound has gone :-)))))))))))))))))))))
Left strut was leaking, but not really visible in assembled condition. The mounts still looked very fine, so no really need to change them, but as I had purchased them, I substituted them as well.

I was really surprised about the much better driving after the parts change. Either on very bad streets, suspension has improved this much!

francis123

After ~10.000km knocking sound is back on front axle, both sides, sound seems to be more loud on right side than on drivers side. I go crazy with that!!!!

Since sound came back I've replaced:

- 3 times strut right side, 1 time left side
- strut mounts
- link assys
- stabilizer bar bushes
- upper control arms
- lower ball joints

Only lower control arm wasn't replaced, but all the bushes are looking very good and I can't imagine that those big bushes are worn out after 110.000km. Sound ist noticeable up to a speed of ~20km/h if small bumps are passed.

Any idea of other possible error sources? One friend mentioned, that as well steering rack could be cause the "knock knock" sound.

Thanks a lot!

sam12345

iTrader: (1)

what brand of struts and mounts did you use? also check your upper control arms if you bought a crappy brand of those they will go out very quickly