I took the passenger side front wheel off yesterday to access the headlamp housing. While jacking up the car it hissed a great deal.
I removed the wheel well cowling and a part fell out, hanging from its wires. I'm guessing it is some sort of sensor, flat, about six inches long and maybe three or four across. Apparently the plastic part holding it broke off. It was held in place by the screw right at the edge of the wheel well.

As far as I know I made no other disconnections. When I reassembled the parts I could not position this properly so it is sitting loose behind the cowling.
The problem is that now the car sits too low and will not rise up. I get the Air Suspension Fault warning after two minutes and it just stays on. That has come on in the past and I replaced the piston ring at Christmas time. But now it's simply not recharging at all. I don't know if that sensor has anything to do with it.

Side note: The car hisses momentarily almost every time I exit the vehicle.
Side note 2: The jack seems to have stripped its gears when I was letting the car down. I had to use three other jacks to get it down completely and the provided jack will no longer turn. Is this a common occurrence?

 

You might need the X350 forums - the 308's never had actual air suspension.

 

I took the passenger side front wheel off yesterday to access the headlamp housing. While jacking up the car it hissed a great deal.
I removed the wheel well cowling and a part fell out, hanging from its wires. I'm guessing it is some sort of sensor, flat, about six inches long and maybe three or four across. Apparently the plastic part holding it broke off. It was held in place by the screw right at the edge of the wheel well.

As far as I know I made no other disconnections. When I reassembled the parts I could not position this part properly so it is sitting loose behind the cowling.
The problem is that now the car sits too low and will not rise up. I get the Air Suspension Fault warning after two minutes and it just stays on. That has come on in the past and I replaced the piston ring at Christmas time. But now it's simply not recharging at all. I don't know if that sensor has anything to do with it.

Side note: The car hisses momentarily almost every time I exit the vehicle.
Side note 2: The jack seems to have stripped its gears when I was letting the car down. I had to use three other jacks to get it down completely and the provided jack will no longer turn. Is this a common occurrence?

 

Sounds like the TPMS sensor. But shouldn't affect ride height. Did you wack the height sensor while you were in there?
A SHORT hiss upon exit is normal, as long as it levels to the normal height, and level. Have you checked for leaks on that unit. 2 minutes sounds like the "time out" period. Does the compressor run? If you have a leak, that may have been the reason the compressor needed a rebuild (overworking). Soap it up, and let us know.

 

Ok slow down,Hoss. I need some explanation. First, what is a TPMS sensor? (I did reposition it properly within the fender, but it didn't make a difference with the air suspension.)
I don't see how I could have damaged the height sensor, I'm not exactly sure where it is, but from the diagram I have it appears to be part of the suspension, which I did not touch.
I've never been able to determine where the hiss comes from but appears to be coming from the right-front, where, according to the diagrams, there are no air suspension components.
The compressor appeared to be working up until I jacked up the car the other day, but how well I cannot tell. We still got air suspension fault messages from time to time, and occasionally "Vehicle too low" messages even after I replaced the piston ring. Now that appears to be the permanent condition.
When you say "soap it up" where do you mean?
A training bulletin that I have says the air suspension system must be calibrated via "WDS". Do you know what that stands for? And would anyone besides a Jaguar dealership have one of these? (The nearest dealership is over 300 miles away--in either direction.)

Thanks!

 

Run the engine and if it does not come up, if possible drive it around for a bit.

 

Thanks, but that was the very first thing I tried. I even took it up to over 60 mph to see if another mode would kick in. No effect.

Keep the ideas coming.

BTW, do you know what WDS stands for?

 

WDS is the jaguar dealer level software package/program that's used for diagnostics and programming the cars modules.

 

If you heard the his from the wheel you jacked, it could be that you have a leak in the bag, and exposed it it when jacking. The normal hiss when shut off comes from the front left at the compressor. The "Vehicle too low" usually is when the compressor cannot meet the needs of the leveling system requirements, and times out. This, many times is a result of a leak. Many times a bag can leak, but only when a crack/leak is exposed on the bag. IE rolled out to full extension. I would start by confirming the compressor is running when you start the car. If it is, repeat the previous repair scenario as in jack the car the same way, remove the wheel, and spay the shock bag with a soapy solution to check for leaks in the bag. If you can, support the suspension a little as to give the bag some slight resistance.
Are any of the other wheels low, or just the front right? Many times when there is a compressor issue all 4 are sitting low. Re calibrating is only necessary when suspension parts are changed, or adjusted. As you only removed the wheel and did not disturb anything else, re cal should not be needed.
TPMS is "tire pressure monitoring system", and does not affect ride height.
Also, if you have a code reader and report the codes to us, it may narrow it down a bit.

 

Mark,
Forget reading the codes as I suggested. After reading some of your past threads on this issue, it seems that your strut may be leaking. No air should be released from the shock unit (including the top ring) when self-leveling. You stated in the past that you found bubbles in the top of the unit. By just rebuilding the compressor and not addressing the leak in the top of the shock, you strengthened the compressor that compensated for the leak a bit. The good news is that you have a good strong compressor now. But you may need a shock unit. The slight leak from the past may have caused the rebuild of the compressor, as it was working overtime to compensate for the slight leak, which is no longer slight.

 

Hi Mark,

I have moved your post from the forum for the X308 to the forum for the X350, assuming your Jaguar with air suspension is a 2003/2004-2009 XJ saloon/sedan. Please let us know if your Jag is a different model or vintage.

Starting at the end of your post, it is completely normal to hear a hiss from the front of the vehicle when you shut off the engine and exit. This is the exhaust solenoid valve on the air compressor opening to backflow dry air from the suspension system through the air dryer to partially reactivate the desiccant beads, and also in some cases to relieve excess system pressure so the Air Suspension Control Module (ASM) can lower one or more corners to make the vehicle sit more level.

If you have not driven the car because it will not raise up, it may be in jacking mode, which disables height adjustments. You may need to drive it over 3 mph before it will exit jacking mode and raise up. If you've driven it and it still won't raise, the height sensor may have been displaced or damaged while you were using all those jacks. For more than you ever wanted to know about the air suspension, see this thread:

Air Suspension & ECATS System Summary: Components & Operation

The hissing you heard while jacking up the car could indicate a leak in the bladder of your front right air spring/damper.

Regarding the component that fell out when you disconnected the wheel arch liner, I can't think of an important component inside the right fender - does your car have aftermarket HID headlamp bulbs, and if so, could that have been the ballast for the headlamp burner?

Cheers,

Don

 

Don this is a duplicate post. It already exists on the x350 forum in which the op has not replied.

 

Thanks for the heads up, Mark. I have merged both threads.

Cheers,

Don

 

Mark,

The fact is I only saw one or two bubbles that first time and none when I checked a few weeks later. It might just have been bubbles in the mixture, not caused by ;leaking air.
I have yet to try and look for a leak farther down on the strut. Also I am limited to hand tools and flashlights, so getting things done takes a lot longer than it would in a shop. I'll let you know when I have soaped it up as you say.

Thanks!

 

Hi Mark,

The top ring Mark in Maine referred to is the top seal of the air spring/shock assembly, and they are known to leak in cool and cold weather, then seal back up in warmer temperatures. If you have this type of leak, you may be able to find it on a cold morning with the soap test.

If your leak is from the air bladder itself, it may be difficult to locate because of the cylindrical metal shield in which the bladder is encased. The best method I can recommend is to run the engine and allow the compressor to fully pressurize the suspension, shut off the engine, raise the car and support it at the proper jacking point, remove the wheel, and use a mechanic's stethoscope or a long socket extension or screwdriver to probe the metal shield on the air spring/shock and listen at the other end of the tool for sounds of air leaking. You can run the engine/compressor while the vehicle is raised to recharge the system, but this may confuse the ASM. Any errors will typically clear on their own after you drive the car again, or can be cleared with a hard reset (disconnecting the battery negative cable and touching it firmly to the positive cable for a couple of minutes to drain the charges from the various keep-alive-memory capacitors).

Cheers,

Don

 

Put both sides up on jacks and sprayed soapy water all around the air suspension struts and compressor. No bubbles seen. I also checked the fuse.
What next?

The compressor with suds.

The strut.

This was the sensor (on the other side) that I mentioned was hanging down.

 

What is the best way to check that the compressor is running? There are no visible moving parts.

 

Hi Mark,

You can typically hear the compressor when it is running if the car is in Park and the engine is idling. If your compressor is especially quiet, it may help to start the car, then step out to the front left bumper area and listen for the compressor.

If you are unable to hear it, you can definitely feel it vibrate if you put a hand on it while it is running.

Cheers,

Don

 

I did what seems now to be a no brainer. I couldn't tell if the compressor was running in context. So I disconnected the air hose at the strut and turned the engine on. There was quite the noise of air coming out of the hose. Then when I covered the end with my finger and held it for a while (no small feat when pressure built up) I could see the driver's side begin to lift. So apparently the leak is in the strut itself.