mann777

I need help, do others also have the same problem as what i started to face recently. On parking the car in my garage or anywhere else, after engine shut down and locking the door, There is long Air hiss noise and observed the rear wheel getting lowered by around 1 - 1/1/2 inch. Then on start the car raises itself to the required level, and can hear the air suspension pump raising its bar to the normal level. Do others have the same effect, or is it something wrong on the sensor height control.

The G Man

The air suspension bleeds itself everytime you shut off the truck, its normal.

Robertsarg

Yes, This is normal. My car does this as well. It is the air suspension bleeding itself.

mann777

thanks guys, but i also have a query, i do have friend in NY who has a 2008 GX model, he never heard this hissing noise on shut off, or is it this bleeding procedure is only in older model. Maybe they could have improverised the bleed technology on the newer model.

BobsGX

I had an 05, 06 and now an 07 GX and none of them hissed after shutting off the engine.

Booyah

My new 08 Hisssssss at shutdown every time

snhrph

My 06 does the same. It's absolutely normal.

mann777

I am confused??? I called up yesterday sewell dallas ... the foreman say it should not hissss. Just to make sure he is right I made another call to Greenville Lexus.. he say it is a normal procedure of the Air bleed hissing out, there is a valve in the air pump, as soon as the engine is powered off. The vehicle ecm detects the level of the car and then does a self levelling by release of the additional air out of the pump. The air suspension equipped on the GX have a bladder technology where the air pump charges the shocks from the compressor to maintain the height and ride comfort. As soon as the ignition key is inserted and just turned to mode "ON" the level sensors gets engaged and determines the vehicle altitude from four sensors equipped on the vehicle. Sensors on the wheels,Vehicle speed sensors,Door Sensors,Throttle position sensor. Once this determined, on start of the vehicle, the compressor pumps air into the air suspension. This is released as per the vehicle height sensors. This information was bit hi-tech for me going over head, that I did not know this detail system existed on the vehicle WOW !! . The only thing to worry is if the vehicle on parking ensure after engine is shut off. The vehicle should rest flat, for any reason if there is drop or slant in the vehicle sides, that mean the air suspension need adjustment, And the dealer only has tools to do the adjustment, and at this stage the height sensors have to be replaced. Each sensor cost 275/-buck!! And there are 4 height sensors at the rear of the GX. Woooow news to me.!!!

Lexus 4 ME

Its funny I had the same question in mind. Mine 2005 GX does exactly the same. So its normal, I even checked the manual.

LexusBob

My '05 hisses too and it is normal.

Booyah

SO if we were to hook up a boat or something that would bring the rear end down--the self leveling would bring the rear back up to level correct?

DrVolkl

It seems like mine only hisses when I park it on an uneven surface. Lately it hasn't been doing it.

Who knows...seems to have a mind of its own.

bronz

haha yup thats normal, nothings wrong with your car.

The G Man

Its just trying to level itself when you park on un-even ground.

Lexus 4 ME

Actually it does, self-leveling. When I hook up a trailer with another car on it, after I turn the car off, it self levels out.