Intermittent air suspension lowering - where to start troubleshooting.
#1
Intermittent air suspension lowering - where to start troubleshooting.
Hi, I have a 2005 XJR that has just given me an all-round lowering of the car, with a car too low message, overnight, on 2 occasions, separated by 4 days/nights with no problems. The car started up fine but displayed the car too low message, until it rose up back to normal height on both occasions and was fine for the rest of the time. The car is a daily driver covering 30-40km daily.
I was thinking that the cause may be from a leak in a common pipe, valve or reservoir, but I can't understand why it was fine for 4 days before the second occurrence, and am wondering if it could be an electronic controller issue as well.
Our temperatures here are 80F (more or less) and we have no winter, although it has been very wet for the past month. This last week however was relatively drier than the previous weeks though.
The car has had 4 Arnotts shocks and a new compressor put in about 6 months ago, and has been fine since then. No work has been done on the car, except for the car being sent for polishing / detailing the afternoon before the first occurrence of the suspension being too low.
Can anybody suggest where I should start troubleshooting? Thanks.
I was thinking that the cause may be from a leak in a common pipe, valve or reservoir, but I can't understand why it was fine for 4 days before the second occurrence, and am wondering if it could be an electronic controller issue as well.
Our temperatures here are 80F (more or less) and we have no winter, although it has been very wet for the past month. This last week however was relatively drier than the previous weeks though.
The car has had 4 Arnotts shocks and a new compressor put in about 6 months ago, and has been fine since then. No work has been done on the car, except for the car being sent for polishing / detailing the afternoon before the first occurrence of the suspension being too low.
Can anybody suggest where I should start troubleshooting? Thanks.
#2
#3
Yes all round lowering. I've already been through the tedious exercise of troubleshooting asymmetric height differences between the left and right side, and the front and back earlier in the year, resulting in the change of all the shocks and the pump 6 months ago. That's why this surprises me as well, to have all 4 go down simultaneously overnight, and only on two nights, separated by 4 days with no problems.
I'm wondering if there could be a erroneous command signal that is activating this intermittently.
I'm wondering if there could be a erroneous command signal that is activating this intermittently.
#5
The car does occasionally wake up and check that it is level and adjust accordingly if it is not, so it is feasible for the car to sit low on all four corners as it can only lower the car to compensate in sleep mode.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
#6
The car does occasionally wake up and check that it is level and adjust accordingly if it is not, so it is feasible for the car to sit low on all four corners as it can only lower the car to compensate in sleep mode.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
My 04 VDP did that.
Last month, I turned off the ignition and watched as the LF shock lowered, then the RF started to lower, then both rear shocks lowered to match.
I started the engine waited till all shocks were fully inflated and the car level, turned off the ignition...disconnected the connecter to the valve block and within half an hour, I found the O-rings were bad at the air-line fitting on the LF shock. The LF shock lowered and the other 3 stayed inflated.
#7
The car does occasionally wake up and check that it is level and adjust accordingly if it is not, so it is feasible for the car to sit low on all four corners as it can only lower the car to compensate in sleep mode.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
Trending Topics
#8
It lowered all the way 4 times before I did my little experiment.
Got the Warning all 4 times till the suspension was a few inches higher. The first time it lowered, I was at work, had to drive home slowly cause the suspension did not lift.
I would love to install some type of manual control for each shock.
Got the Warning all 4 times till the suspension was a few inches higher. The first time it lowered, I was at work, had to drive home slowly cause the suspension did not lift.
I would love to install some type of manual control for each shock.
#9
Unfortunately my back-up car is in the workshop currently for long awaited mods so I haven't been able to send the Jag in for checking yet. Just hoping it won't get worse for another week, when the other car hopefully comes out. (Of course the Jag has to pick this week to misbehave....)
#10
The car does occasionally wake up and check that it is level and adjust accordingly if it is not, so it is feasible for the car to sit low on all four corners as it can only lower the car to compensate in sleep mode.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
I would assume therefore that if you have one leaking spring the car will eventually lower the others to match.
#11
It lowered all the way 4 times before I did my little experiment.
Got the Warning all 4 times till the suspension was a few inches higher. The first time it lowered, I was at work, had to drive home slowly cause the suspension did not lift.
I would love to install some type of manual control for each shock.
Got the Warning all 4 times till the suspension was a few inches higher. The first time it lowered, I was at work, had to drive home slowly cause the suspension did not lift.
I would love to install some type of manual control for each shock.
#12
#13
#15
Thanks for the suggestion. I'll try that if the problem becomes more consistent. Right now, as it happens once in 3-4 days I wouldn't know if it's ok because of the disconnect or because it just wasn't time for the problem to show itself again.
#16
It lowered every time the temp went below 50 degress F.
I got the left repaired but now the right shock is leaking at the top, but again, only below 50 degrees F.
I tested the temp theory twice last week and this past weekend, as last week the temps were below 40 degees F and this weekened the temps were above 50 degrees F. Last week, I moved the XJ in and out of the garage to check the leakage. Left it out for an hour and the front went down all the way. Moved it back in the garage and it stayed inflated.
Does anyone have an old front shock (not usable) laying around? I would like to tear it apart to see what components/areas are causing them to leak.
#17
#19
Join Date: Sep 2008
Location: Damon /Houston, Texas
Posts: 7,254
Received 2,193 Likes
on
1,359 Posts
Those are not vents. Theyre just holes in the top of the shock mount over the foam upper shock bushing that is also open all along the side inside the center ring for the shock nut and shaft. That is a captured bushing idf there is a air leak in the top of the mount behind that bushing it is not repairable. Be sure and tighten that shock nut on the shaft because that lets the top plate come loose inside, and verify the air line and adpter it threads into are not leaking. These are also 2 leak points
The following users liked this post:
klfong (12-21-2011)