HELP: Is it Normal that the Car Sets lower "self leveling" overnight?




I assume everyone will say it'an Airmatic leak issue, but so far that car has been serviced and couple of check points including suspension were completed and there has been no concerns addressed.
I wonder if this is something you guys also notice (you have to be really picky to notice that, and leave it for >1-2 days not driven). I read couple of articles that the car sets lower overnight sometimes due to self-leveling feature? I also have to say that the spot I park at night is not 100% leveled, there is an incline of few degrees.
Last edited by S_W222; Nov 10, 2019 at 09:47 AM.




Last edited by S_W222; Nov 9, 2019 at 09:35 AM.




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I am literally talking about 0.5 inch maximum difference, and it's 35F now in the morning compared to warmer temperature in the 60-70 when I parked it. If this is something that you all notice, then am not too worries about it. Just wanted to see of other users are noticing the same....
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Last edited by konigstiger; Nov 9, 2019 at 10:13 AM.
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A certain amount of suspension drop due to thermal contraction is normal and should not be regarded as a malfunction. Approximately 30 mm of
suspension dropping in cold temperatures is within design parameters
I just found the statement above, that was copied as, in this document below:
https://f01.justanswer.com/73bbchevy..._code+5507.pdf




Last edited by Utopia Texas; Nov 9, 2019 at 12:16 PM.








I've been taking measurements (distance between the lower edge of the rim to the fender) over past 2 days:
Baseline: 27.25 inches (day 1 morning)
after 12 hours: 26.75 inches (day 1 night )
after 24 hours: 26.75 inches (day 2 morning)
after 36 hours: 26.75 inches (day 2 night).
So far it looks it sets lower by 0.5 inches overnight (day1) and then hopefully it stabilizes.... i'll wait one more day tomorrow to confirm. If it stays at 26.75 inches it means it just the thermal contraction of air in the airmatic system.
Last edited by S_W222; Nov 9, 2019 at 11:20 PM.




I always thought the car looks better that way. As soon as you start it is back to normal.
I've been taking measurements (distance between the lower edge of the rim to the fender) over past 2 days:
Baseline: 27.25 inches (day 1 morning)
after 12 hours: 26.75 inches (day 1 night )
after 24 hours: 26.75 inches (day 2 morning)
after 36 hours: 26.75 inches (day 2 night).
So far it looks it sets lower by 0.5 inches overnight (day1) and then hopefully it stabilizes.... i'll wait one more day tomorrow to confirm. If it stays at 26.75 inches it means it just the thermal contraction of air in the airmatic system.




Distance between the lower edge of the rim to the fender) over past 3 days:
Baseline: 27.25 inches (day 1 morning)
after 12 hours: 26.75 inches (day 1 night )
after 24 hours: 26.75 inches (day 2 morning)
after 36 hours: 26.75 inches (day 2 night).
After 48 hours: 26.75 inches (day 3 morning)
Experiment is done. This confirms the air contraction theory for the W222 AIRMATIC system, during first 12 hrs only before it stabilizes, with around 0.5 inches due to air contraction. This happens when ambient temperature of air inside suspension drops to 30-40F or lower, yielding a lower air density and thus a smaller air volume in the suspension which causes the car to set lower.
**For the record, these measurements were taken at temperature of 32-35F. I expect the contraction to increase by another 30% based on air density at 15F or lower, meaning another 0.25 inch for a total of 0.75 inches at colder temperatures such as 20F or lower.
Based on this, 0.75 inches of height difference is within design parameters, however, for those who experience more than 1-inch of height difference overnight, i would encourage them to test for any potential air leak especially during summer or when temperature is not that low.
Last edited by S_W222; Nov 10, 2019 at 09:58 AM.






