Front air shocks replaced 15,000 miles ago (60k) by prior owner. Last night I had a low tire pressure warning at LR. It was in the low 20s F and that cleared after the tire warmed, or at least I suspect so, and that fact I suspect is a red herring.
Tonight, the car ran normally for about 2 minutes after startup (very low temps too), but rode hard. Air suspension fault light came on, and about 90 seconds after that, on brisk acceleration, the red “car too low” light came on. I turned around, parked it and jumped in my Prius (a contrast in automotive tastes!).
Any likely suspects? It’d be a great new year’s present to learn it’s just cold weather, but that’s not the sort of luck I usually have!
I should add via this edit that I do not have a garage so the car sits out in the cold.
Happy new year’s to all Jag sorts.
Eliot Brenner
Annnadale, VA
‘06 X350 VDP, and now deceased XJ40 and an X300L
I have two 2005 XJ8. One has the stock air shocks;the other has the Arnott conversion shocks (doing away with entire air hydraulic system). I’m selling soon the stock system because the air shocks are constant problems. BTW, I see very little, if any, difference in the ride of the converted car which is a Vanden Plas (another reason I am keeping it)!
I suspect the reason you are seeing “car is too low” is because one of the diaphrams in one of the front air shocks is leaking. The leak is much worst in the cold weather. When the temperature rises, the leak MAY disappear. Another possibility is the air compressor behind the front bumper (on the driver’s side) has given up or the relay is bad (found in the fuse box front right). It can be easily rebuilt using a kit. What you can do is start the car while getting close to the compressor to see if you hear it running. It should be running constantly trying to pump up the shocks. If it is running, try listening to each air shock to see if you hear air escaping. On mine, I could actually hear air hissing out of the shock. I replaced it with a used shock which remains ok as of last week. Honestly, I am selling the 05 with the OEM system because of the air shocks. I’m tired of worrying about the system. I have several ftont/rear shocks and the compressor I will be selling because of selling the stock XJ8.
Hi Eliot, Richard has said it all!. Our 05XJ8L sits outside in winter ( ON Canada ), and we have had the same problems as you. Front shocks/compressor replaced. Basically this car is NOT suited to cold conditions. Apart from that its a great car.
Richard/John: Thanks for the guidance. It may have been Richard who told me as I was buying this car in mid-2016 that the shocks did not like cold weather. Someone did. I do not have a garage, and so I got an unpleasant New Year’s gift. If I had a garage things might have been different.
Richard: It appears you are spot on. I hear the compressor running when I start the car, which is nose-low, so I see no need to check the F6 fuse, especially since it is in the teens here and I’m afraid trying to crack open the fuse box may actually crack the latches! However, the one odd bit is that the compressor shuts down after a couple of minutes, and I do not hear it kick back in within what I’d consider a reasonable period.
My ears are not good enough to differentiate between the sound of air moving from the fan and air escaping a shock, but your long-distance diagnosis appears right on the money.
It looks to me price-wise I can convert the system with the Arnott kit for about the cost of replacing two air shocks. Without a garage, I have to hire out this kind of work, but it’s not so much money that I’ll choke on it. I’m going to wait a bit before doing anything to see if I get a warm day and the system starts working again. If so, I can at least plan for a late summer conversion rather than spending the money now.
With thanks to you both, and wishes for a Jag-malady free 2018 …
Gents: I let the car sit until today when the temperature approached 50 F. When I fired it up, the shocks jacked up to the proper height and the “car too low” warning turned off. I drove it a bit, shut it down to fuel, and upon restarting the warning “air suspension fault” light cleared. I took a moment when passing another service station to put a bit of extra air in the tires just to ward off cold-weather low tire pressure cautions.
This by no means is a sign that all is well. Clearly the cold caused the front shocks to lose air. But it is at least a hopeful sign that — temperatures permitting — I do not have to tackle this job immediately. Sure wish I had a garage that would keep the car at a more car-friendly temperature!
I know this is late and I hope you fixed your prob, already. I had the same issues with my '06. I used the “soapy water” test to find that my fronts were leaking from the bladder. (yeah, I know). Anyway, a new pair of Arnotts cured the problem for 5 years when one of them started leaking perhaps caused by me when doing suspension work. True to their warranty they sent me a new one. However, they no longer rebuild old shocks, they manufacture their own. These are not “smart” shocks like the OEMs and will not go into hard mode nor will they lower at high speed. Still, they are a bargain compared to stock. A popular alternative is their coil-overs that replace the air springs altogether.
Rick: Thanks for reaching out. For now, all seems well. I let it idle a minute, the nose rises, and off I drive. I’ve not done anything, but if it misbehaves again, I think I’ll do the coil-over conversion. Then again, I just might get rid of it and get an XK.
I don’t know how to do the “soapy water” test. Might be worth doing. If you have a link to an explanation, I’d appreciate knowing how to do it. I don’t have a garage so I can only play with the car when it’s warm out.
Hope I didn’t appear to be glib, the “soapy water” test is mixing dish detergent with water and then applying it to the area in question. If there’s an air leak bubbles will form. The same way you test for tire leaks. Originally I used it to test the top of the air spring where the air supply enters. That didn’t have any bubbles but as the water ran down the spring they showed up.
Mine still droops a little sometimes but comes back like yours. I’m at the same point I’ll either live with it or get another car.
Rick: Not to worry. I know how to make soapy water to test for a leak. What I was trying to figure out, and did not make myself clear, was how to gain visual access to the exterior of the bladder below the upper mounting area to put soapy water on it to see if it bubbles anywhere. I don’t have a garage or access to a lift.