I am new to the forum so please be kind. I am trying to get help for my Mom's 2004 XJ8 Vanden Plaus. The air suspension is not filling up and the car is giving an error message saying "Vehicle Too Low." I am a Jeep guy and work on it all the time and have performed quite a bit of repairs and modifcations to it so I feel I could be qualified to take a shot at fixing this car as long as I don't need a computer or some super special tool. The car has been sitting for nearly two weeks while she was out of town. My dad said he disconnecte the air line at the spring and said he could hear the compressor working and feel air coming through the line but it just doesn't want to raise up. I got out there and fooled around with it for a bit and noticed what I can only describe as a clunking/gurgling noise coming from the radiator area that continues for a minute after the engine is shut off. This noise is not really consistent or harmonic in nature. My parents are very low on cash these days with the awful economy and don't have the money to stick it in the shop so they really need me to fix it if I can. Please help me out if you can.

 

The common opinion around here is that the compressor is the weak link and they fail a lot. Jag gets a lot for one. Arnott gets about half but.... interestingly, I may have to replace a 5 month old Arnott unit on my wife's car. They do claim a one year warranty but I haven't got to that point yet. Will post back afterwards but that won't help you now.

 

Ben824
Do a search of this forum and look for posts from SteveTech. That should get your education started not only to diagnose the problem but fix it yourself-- if you are so enclined after reading up on the problem.
If SteveTech's write up makes sense to you, go for it. If not, seek professional help.

 

We also have posted a link to rebuilt air shocks, if it turns out to be that. $400 isn't that bad compared to a new unit.

It makes sense that an air shock leaks, the compressor works harder and longer to keep the ride height level, and often burns out the compressor. So, if it is the air shock, lets hope the compressor isn't toast as well.

Air lines are the first to check obviously. Others have diagnosed a bad shock by pulling the line on one, plugging it, and letting the other 3 air up successfully. Obviously, if more than one are bad, this diagnosis technique won't work.

 

Ok so I did a little more researching and I found Arnott's site and see that they sell the air shocks and the compressor. First question I have I these quality replacement parts? I have read in a couple of places where the compressors they make have gone bad in 5 months. I think my problem is at the passenger side shock because when the engine is shut off the is a very notable air rushing sound coming from that side that is not heard from any other shock.

My second question is which shock should I choose? they have a "comfort suspension" and a "sport suspension." I am assuming that a Vanden Plaus like our car would use the comfort suspension unit and models like the XJR would use the sport suspension unit.

 

when in doubt, either call them or give them a dealer part to cross reference from. That logic though, sounds very plausible.

I would trust the rebuilt, with a warranty for sure.

 

If you hear air thats the leaker. I diag with air suspension up. Measure all 4 corners ride height at the center of the wheel opening and record. Theyre not susposed to be equal. Then take out the spare to access the air distribution block in the trunk. Unplug the electrical connector on the side of the block and let sit overnight. This will keep the car from trying to keep the car level and the corner that drops has the leaking air spring...ive never seen a line leak so forget that