Unknown sound - KDSS SYSTEM? (1 Viewer)

[Esthlos13]

Hi everyone - I will caveat that I am no car expert just really love this vehicle. It’s a 2013 USA Lc200. I’ve had this sound for a few years- have left it at multiple Pittsburgh Toyota dealers for weeks where stated they were never able to replicate this sound yet seconds after driving off its audible to me. I will caveat this sound changes somewhat with the temperature, and is mostly heard when the vehicle moves left to right/ hits a bump at a slow speed. It stops if brakes are applied but I don’t know if that’s a direct connection or just by virtue of the vehicle no longer moving. Do not hear this at highway speeds but maybe road noise drowns it out. When in the vehicle it sounds like it’s coming from the dash, however when getting under the truck it’s most audible near/under driver side second row almost as though it’s in the frame, but given that’s where the KDSS system runs I’m wondering if this is some kind of fluid sound. Absolutely drives me nuts.

 

[grinchy]

something rolling around inside the frame rail?

 

[bloc]

To rule out KDSS open the shutter valves and repeat your rocking test.

Opening those valves (NO MORE THAN 3 TURNS) allows all of the pressure circuits in the system to equalize so the rocking won't actually be putting any force on the bars.

 

[Esthlos13]

I don’t think it’s something rolling in the frame rail just based on how the sound works (in person, video doesn’t capture everything well)

BLOC- I saw you did a giant thread on the KDSS, I wish I understood 10% of it .
Is what you recommend doing something relatively simple with low probability of making something worse? I tried googling a bit but couldn’t find any leads on where exactly these valves are/ what tools required to loose. Thanks!