Last week we had our first below-freezing temperatures in North Texas. I left for work and everything was fine, but after about 2 miles the ride became very bumpy. I pulled into a parking lot and saw that the front of my Navigator was very low (both sides were equally low). The rear was at the normal level. The compressor was running, and while I was looking for the problem the front raised back up and I was able to continue driving to work. It has not happened since (it has not been below freezing either). This weekend I crawled around underneath checking the air lines, compressor, listening for leaks, etc. Everything looked OK to me. It has 100k miles, and nothing has ever been done to the suspension. I don't want to convert to coil springs because I like the air ride and don't want to have error messages on the dash. Does anyone have any suggestions about the most likely cause? It looks like there might be some O-rings that seal the solenoids. Would that be a good place to start? Thanks in advance for any help you can offer.

 

First check the front height sensors to make sure they haven't broken loose from their mounts.

 

Height sensors look fine.

 

The system tends to pump up the rear shocks first before the front so maybe it was having a hard time getting the rear shocks aired up. The compressor seems to be slower when cold and your is getting old. I replaced my compressor earlier this year on my 2004.