Air suspension at work upon start

[Yahoo Square]

I started noticing that my L adjusts its height slightly (probably auto leveling) after I started the car. The height adjustment upon entry/exit is off and I don't think it did before. Maybe air is leaking and it is trying to compensate it? or maybe it's normal and I am hyper sensitive?

 

[FlyingAvocado]

I started noticing that my L adjusts its height slightly (probably auto leveling) after I started the car. The height adjustment upon entry/exit is off and I don't think it did before. Maybe air is leaking and it is trying to compensate it? or maybe it's normal and I am hyper sensitive?

I am not sure about the behavior, but it's a closed loop system so if it was leaking it probably wouldn't function properly at all.

 

[SweetAndLow]

I am not sure about the behavior, but it's a closed loop system so if it was leaking it probably wouldn't function properly at all.

If there is a little leak the air gets replaced with the compressor bringing in more air from the atmosphere. You can actually assume there is going to be small leaks throughout the system that's why it's built that way.

@Yahoo Square I think the only way to test would be to measure the distance from center of hub to the fender for a couple days while it sits there and you don't drive it. If it slowly gets lower and lower then yeah you got a small leak. The other things that can happen is you get a message about 'air suspension cooling down' and the compressor runs more than it should so it overheats or you get a CEL/DTC about low air mass when the vehicle starts up and senses the low pressure in the system from the leak.

Sometimes a bottle of soapy water can help find the leak if you want to try and look around for fittings and connections.

 

[Yahoo Square]

Yeah, I think I will measure the distance from the hub to the fender and see. Thank you.

 

[eleceng1979]

The system is 100% sealed and uses nitrogen. Here is a good read…

Jeep WK2 Grand Cherokee Quadra-Lift Air Suspension System

Welcome to the JeepSpecs.com in-depth page on the WK2 Jeep Grand Cherokee Quadra-lift air suspension system. Did we miss anything? get in touch with us and let us know! The Quadra-Lift air suspension system provides height control and lifts the vehicle up to 4.1 inches from park mode to a...

jeepspecs.com

I have noticed the same behavior, start, rear end comes up a bit. My use of the vehicle is for entire family outings, so I only get into it for these reasons. It is used only by my wife in between. So a big weight difference as I weigh 2.5X my wife weight. When I get in it auto levels. Jeeps way of saying I’m fat, or at least much heavier than my wife.

My 2012 & 2019 GC with QL didn’t auto level like this at startup. Not sure wether it’s a bug or a feature. Mine does behave the same as yours.

If you have a leak you will know it. The compressor will run constantly and overheat. Not to mention suspension height low. The 2011/2012 GC had lots of problems with QL when introduced. Many compressors were changed and tanks refilled

 

[freethinked]

I think it’s intentional. Goes horizontal when off to make it look nice then lowers the front a bit when started to keep headlights out of the eye of oncoming traffic.

 

[SweetAndLow]

I think it’s intentional. Goes horizontal when off to make it look nice then lowers the front a bit when started to keep headlights out of the eye of oncoming traffic.

No it doesn't do this. You can enable entry exit mode if you want but if it's disabled it stays in the previous drive mode.

 

[Yahoo Square]

The system is 100% sealed and uses nitrogen. Here is a good read…

Jeep WK2 Grand Cherokee Quadra-Lift Air Suspension System

Welcome to the JeepSpecs.com in-depth page on the WK2 Jeep Grand Cherokee Quadra-lift air suspension system. Did we miss anything? get in touch with us and let us know! The Quadra-Lift air suspension system provides height control and lifts the vehicle up to 4.1 inches from park mode to a...

jeepspecs.com

I have noticed the same behavior, start, rear end comes up a bit. My use of the vehicle is for entire family outings, so I only get into it for these reasons. It is used only by my wife in between. So a big weight difference as I weigh 2.5X my wife weight. When I get in it auto levels. Jeeps way of saying I’m fat, or at least much heavier than my wife.

My 2012 & 2019 GC with QL didn’t auto level like this at startup. Not sure wether it’s a bug or a feature. Mine does behave the same as yours.

If you have a leak you will know it. The compressor will run constantly and overheat. Not to mention suspension height low. The 2011/2012 GC had lots of problems with QL when introduced. Many compressors were changed and tanks refilled

Good read! and you are right! It tries to maintain certain height (around 25" ground to rear fender), and this happens when the load before turning off the car is different from when it is started up. Here is the observation yesterday and today:
25" (ground to rear fender) -> 24 1/2" with ski hitch rack and 4 pairs of ski gears -> 25" after startup -> turn off and unload rack and gears -> 25 1/2" -> remain at the same height till today -> 25" after startup.

It was good to see how this thing works!