Lexus LS430 ride is very soft then becomes rough after 10 minutes

[LuisLS430]

Hello everyone I am new to this group but not new to Lexus, however I have the UL Lexus with air suspension and the ride is very nice and pleasant for about 10 minutes then becomes stiffened and there’s a lot of road imperfection feel and it’s harsh, more than it normally should. I’ve driven a few LS430 before with air sus and theyre fantastic even in sport settings. My car has relatively low miles only a touch above 100,000. 

I do know that the bushes need to be changed, and the control arms as well as the track rod ends, and I was thinking that if they’re all misaligned/ not doing their job properly it could send the computer off and stiffen the suspension a bit too much? Or affect the air suspension.  I really doubt it’s the shocks, there’s no oil leak and they’re not bouncing around the place, and there’s very minimal swaying around the corners. 

help please !! Haha ! (Really need help) 

thanks all, Godspeed!  

[cruisermark]

Hi

This sounds like the ride height sensors locking up on high setting - basically water ingress causes a short circuit within the sensors and you get the symptoms you describe.

when this happens do you notice the rear sits very high? - if this is the case then the height sensors need replacing.

[LuisLS430]

4 hours ago, cruisermark said:

Hi

This sounds like the ride height sensors locking up on high setting - basically water ingress causes a short circuit within the sensors and you get the symptoms you describe.

when this happens do you notice the rear sits very high? - if this is the case then the height sensors need replacing.

Ride height is fine, each side is level there’s never been the case of it being lob sided, 

however i could measure what the distances should be when it is on normal setting ( if you could provide me with some figures👍👍) 

... Could it be the actuators that sit on top of the shocks??? 
 

thanks for the reply! 

[BigBoomer]

The actuators on the top of the shocks control the damping. If the ride height is not changing then it could be that the computers are turning the damping to maximum. How you'd diagnose/fix that I have no idea.
There have been issues with the air control valves not sealing fully, which can lead to overpressure in the struts, but again that leads to the car being in the high position.
First you need to check the ride height front and rear. Measure from the ground to the highest part of the wheel arch, both front and rear. We can do the same and compare heights.
If they are the same, then go for a drive until it gets harsh and then measure again.