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My local Jag guy had my 2003 xjr up on his 2 post lift while replacing the rear parking brake motor unit.
Back on the ground and the front hasn't come fully back up. Rear is at normal height. He has taken it for a couple of drives but its still a couple of inches low at the front. Both sides at the same height. My car is an early one with two front ride height sensors. No suspension fault codes.
Anybody had this problem before? Any suggestions?
You sure /not sure... what was DONE to it whilst on the lift? Could be unrelated?
Replacing struts in my case, so I expected to have leveling issues.... but did not.... 'not really'.
Replaced the right front air strut first - it sat high right side, until I replaced the left one about a week later.
"What I did" .... (for Chinese Suncore struts..) was follow the Bilstein OEM You Tube video as to measuring axle center to fender lip, two stages, ignition OFF in between .. but battery NOT disconnected.. etc - and bled the air out of the FIRST one I had changed so both had to be re-filled by the system when I completed the second strut.
Their videos for front and rear explain it well - and in the order it needs to be done.
'SO far' is has leveled properly, L/R and F/R. with the rear struts still the OEM Bilsteins.
CAVEATS: Haven't yet done my rear struts. Single front height sensor here. Your situation may be entirely different, but.... I don't see much risk in doing it the Bilstein way, whether struts are still sound or already leaking.
PS: The front WAS low for several years in cooler weather as the only strut leaking maxed-out the compressor time-out before it ever satisfied the 'proper' level, but after it had satisfied the 'too low' threshold.
Over several years, the leak at the top of the strut was @ 46 F and below, then @ 52 F and below, then @ 64 F .. 'until it leaked even at 80 F and above. Heat from the engine as it warmed-up the underhood area, and the leak closed-up.
Your struts are how old? Did the work done involve a battery disconnect while suspension was not at normal hight or loading?
A fraction of a cent's worth of kid's entertainment "Bubble Stuff" from the poor-folk's store, and the leak became blindingly obvious!! I'll check these more often, going-forward.
Just a lack of air probably . Might want to check the height sensors condition on the rear . Since work has been don in that area
if you start car again after some rest the compressor will be switched on a couple of seconds after the engine. If still to low on the dash you can drive carefully at about 25mph the compressor is switched on again delivering more air.
Thanks for the replies..
Just drove home, 25 minute journey, speeds up to 80km/hour, no change, still low at the front. Suspension feels hard/crashy at the front. Still no messages or codes.
I don't think I have any leaks in the front struts as the level did not drop overnight. When it was taken off the lift initially it was right down at the front and had to be jacked to get it off the pads, and it did rise up at the front when the engine was started but not all the way.
Anybody know how I can check that the air compressor is healthy? When the ignition turns on I can hear it start, but literally for a couple of seconds before it turns off. It does this each time you turn on the ignition.
I read in the x350 technical guide that when the system first starts it levels the rear first THEN the front. So I'm thinking maybe the compressor isn't doing the job, but this would probably result in a code ... and there are none.
So just read some live data from my scantool, car stationary, engine running, these are the readings from the height sensors;
Rear left 4mm
Rear right 2mm
Front right -42mm
Front left 45mm
So does anybody know what these values typically are? The front ones look a bit weird, minus 42mm??
If you start the engine, the compressor runs a limited time, even if the car is completely low. (This can occur after changing tires with bad leveling.)
I don't remember the exact time, but its about 1minute at max.
This prevents the compressor from overheating.
At a minimum speed (I guess it was 40km/h), the compressor can work longer.
When your car rises always up to the same height and stays there, I don't believe it's a compressor issue.
If you can get your hands on a SDD, try to recalibrate the height. (.. which is pretty easy)
To me it looks like your height sensor is wrong or somehow calibration was lost.
Ordinarily, we would suspect that your air suspension is disabled because it entered Jacking Mode while on the lift, but it should exit Jacking Mode as soon as the vehicle moves at a minimum of 2 mph - 3 km/h.
Is it possible the front ride height sensors popped off their spring clips while the car was lifted?
I wonder if the rear vertical accelerometer might have been disturbed while the EPB motor was replaced? This could disable air suspension operation, but there should be at least one associated DTC triggered.
Air suspension DTCs are Chassis (C-prefix), Body (B-prefix) and Network (U-prefix) codes, so they cannot be read with a standard OBDII scan tool that can only read Powertrain (P-prefix) codes. Can your tool read these additional DTCs?
It might be worthwhile to try a hard reset: disconnect the battery negative cable and touch it to the battery positive cable for at least two minutes to drain the system keep-alive-memory capacitors. Then reconnect the negative cable and see if the air suspension system resets.
So the car doesn't drop over night or when turned off, but it is consistently low at the front.
I just removed both front wheels to look at the height sensors to see if there was anything obviously physically wrong. The left hand bracket was a very small bit out of square but nothing really.
Jacked up the front to do this, so had both front wheels hanging. When I lowered the car it returned to its previous height at the front and rear (Ok at rear but about 2 inches too low at the front) Went for another drive, no change.
Looked at the live data and the readings from the height sensors were pretty much as reported in my last post.
Seems like you (nebelfuerst) could be right, it has lost its calibration somehow...
1. Just got the wheels off and front sensors look OK
2. My jag guy has SDD and there were no codes for the suspension. I'm using a Carsoft to read the live data
3. I'll check on the rear accelerometer, I think this is in the region of the entertainment/nav stuff on the left hand side of the boot/trunk?
4. I'll try a hard reset and see if that solves things
Try to get a SDD. With SDD you can calibrate, but you can also tell the jag to lower/raise the front/back. (Looks like a camel )
In SDD you can enter symtoms about bad suspension/wrong height and then it will show procedures to use.
Try to get a SDD. With SDD you can calibrate, but you can also tell the jag to lower/raise the front/back. (Looks like a camel )
In SDD you can enter symtoms about bad suspension/wrong height and then it will show procedures to use.
My Jag guy has SDD, wouldn't mess with it myself....
I'll get him to do a recalibration and see if that sorts out the problem..
So my thinking is this. The live data from the level sensors was as follows;
FR 45mm
LR minus 42mm
RL 4 mm
RR 2mm
Height at rear looks right. Height at front looks around 2inches low (50mm)
So looks to me like;
the FL sensor is saying we're 42mm too low and is where we're at and is working OK
the FR sensor is saying we're 45mm too high and we're certainly not and is banjaxed.
Conclusion we need a new sensor on the FR.
Going to try this and see if it solves it
So my thinking is this. The live data from the level sensors was as follows;
FR 45mm
LR minus 42mm
RL 4 mm
RR 2mm
Height at rear looks right. Height at front looks around 2inches low (50mm)
So looks to me like;
the FL sensor is saying we're 42mm too low and is where we're at and is working OK
the FR sensor is saying we're 45mm too high and we're certainly not and is banjaxed.
Conclusion we need a new sensor on the FR.
Going to try this and see if it solves it
Strongly recommend replacing sensors in L/R pairs, not one at a time.
And I ask again, how old are your struts? The top seal seems to fail from age (heat cycles, and perhaps airborne nastiness?) not so much from miles/klicks of exercise.
Strongly recommend replacing sensors in L/R pairs, not one at a time.
And I ask again, how old are your struts? The top seal seems to fail from age (heat cycles, and perhaps airborne nastiness?) not so much from miles/klicks of exercise.
We'll try with a used sensor on the suspect side first to see if this goes anyway to solving the problem
Both struts at rear are only a few years old as I replaced these myself with Bilsteins. One of the fronts was replaced just before I bought the car 7 years ago, one I think could be original. But there are no leaks from the struts, the car does not drop over time and never has. Until a few days ago the car was riding great. Strut leaks are not as common in the UK and Ireland as in other parts of the world as our climate is temperate and we don't suffer the extremes (particularly low temps ) that other places in the world do.
Strut leaks are not as common in the UK and Ireland as in other parts of the world as our climate is temperate and we don't suffer the extremes (particularly low temps ) that other places in the world do.
Aye. Extremes of cold 'expose' the leak, but it seems to be the extremes of heat that fail the elastomer - the 'underhood' fronts nealry always failing many years before the rears.. One front had but a really slow leak @ 19 years, neither rear is yet leaking.
So three out of four of mine made it near as dammit 20 years?
Well worth chasing wotever little nit is doing the do since you have Bilsteins. They are well-made.
Even so, for a little as I'll use my X350 - between age 80 and 90 - and mostly on some of the USA's best road surfaces, I couldn't justify Bilsteins at roughy $1,500 per each corner, AKA $6,000 total... cost premium over the Suncore's (or similar priced if not lesser, 'coilovers').
The L320's 5.0l V8 is going to eat that savings.. and more!
So received my used replacement sensor (for the front left hand wheel, I have left/right dyslexia or what ever the equivalent is. It was the front left sensor that was reading +45mm and not changing when I drove the vehicle, earlier in the thread I said it was the front right!!) from the UK and put it on the car this evening.
The replacement sensor included the bracket so tried to remove the old bracket. One bolt came out Ok but the second one turned the captive nut in the subframe. It wasn't going anywhere. So I switched the sensors and left the existing bracket in situ.
Put the car down and started the engine. Got 'a vehicle too low' message which I didn't get before, drove the car 100m and it came back up at the the front, problem solved!!
I have had a bagpipingandy compressor refurb kit and new dryer media on the shelf for a couple of years so took the opportunity to refurb the compressor as well.
So, if your car drops at the front and back is OK or vice versa, check the live data from the level sensors as one could well be toast and the cause of the problem. The sensor I took off was so stiff you could hardly move the arm.
I didn't recalibrate the system, which I have read you have to do when changing a sensor ( I don't have the software to do this) and all wheels are perfectly level. So it doesn't seem it's necessary to recalibrate after replacing a sensor. I didn't disconnect the battery to replace the sensor
Happy Days!
I have an '04 and 10 years ago, I had to change the LF shock. Since I was in plain sight of the compressor, I ordered a rebuild kit from BP Andy. While I don't remember the price, it was almost free even with the mail delivery to Seattle.
If you think your compressor may be underperforming & if you haven't yet rebuilt it, perhaps you might consider it? Knock on wood, I just replaced a second shock and the system couldn't be working better.
If you think your compressor may be underperforming & if you haven't yet rebuilt it, perhaps you might consider it? Knock on wood, I just replaced a second shock and the system couldn't be working better.
Hi Steve. Yes I have just rebuilt it. I had a kit on my shelf for a couple of years and just completed the rebuild.
@04Xjrsteve Steve, what brand shock did you use?
I've followed your work in the Valley of the Hoses. Remarkable job and thanks for all the detail of that work. I think I'm a fair mechanic, but then I see what you've done and I'm quickly humbled.
Thanks for taking the time to detail your exploits here.
~Dale
Thank you so much for the encouraging words! I never thought that I would get into working on my car. However, these are such beauties that it has become a labor of love. I know that if I got rid of her, the odds of her survival would diminish greatly.
The shock I replaced 10 years ago was an Arnott recommendation. However, the most recent one is from Amazon:
& it works great. It has a tit at the top which is what is usually on the rear. However, this one was sold as a front & except for that, as far as I can tell at this point, it works great.
I notice you're in SC. What part? We are originally from the Holy City & get back there occasionally.
07-27-2024, 05:21 PM
Front low after being on 2 post lift
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