The car may have to sit overnight for the system to lose enough pressure for the compressor to be triggered at startup. If I recall, when the car is sitting, the ASM will check every 24 hours to ensure the car is level, and if not, it will open the valves to release air from the strut(s) that is/are high to relevel the car. So unless you have a more rapid air leak somewhere, theoretically your compressor might not need to run unless the car has been sitting at least 24 hours. I hope someone else will chime in to correct me if I'm wrong. Fraser? Abonanao? Leo? Guus? Someone?


It's possible that disconnecting the battery might prompt the ASM to run the compressor, but since it may make that determination solely on the pressure in the system, the battery reset may make no difference.


Based on what I understand about the system operation, it is more likely that the ASM will release air from the struts on the side it perceives as high, but I also recall reading that the ASM has a way of sensing that the vehicle is being jacked up and it then goes into an inactive mode to make no adjustments until the car is level again. I think the Workshop Manual or the New Model Technical Introduction explains this.


Not sure what you're describing - the crankshaft? Rust there shouldn't be a problem as long as the piston connecting rod is not siezed to the crank and the motor shaft will turn freely. You don't want to oil any of the components in the crankcase or cylinder since the oil will quickly work its way into the air system, which is designed to run completely dry.

If you still have the compressor out of the car it would be a great time to hook the compressor motor up to your car battery to see if it will run (don't let it run too long to avoid overheating). Assuming the compressor motor will run, hold your finger at the port of the exhaust valve (not the main threaded air hose outlet port, the molded half-tube on the exhaust valve body). If air escapes from the exhaust valve while the compressor is running, the valve is siezed open, probably from corrosion. I haven't opened our exhaust valve yet to see what it would take to free it up if it was siezed, but let us know what you discover and we'll try to help.

Cheers,

Don

 

Aloha,

for a check of the compressor, it is not necessary to dismount the front left wheel and all that.
You can as well give +12V to fuse 6 of the front power distribution fuse box and let the compressor run.



To test the compressor, perform the following steps:
- Prepare a a thick cable, one end needs a clamp (for the battery), the other end should be a soldered tip (to touch the fuse)
- If you like, you may install a cable fuse of 40 Ampere
- Make sure that the ignition is off, because then relay R1 is open
- Fix the clamp on the plus pole of the cars battery, be careful not to touch anything with the other open end
- Contact the open end to the metal of fuse 6 for a second and hear the compressor snarl



Please do not let the compressor run too long while the ASM is in sleep mode.

If the compressor keeps silent, there is something wrong with either:
- fuse 6 of the front power distribution fuse box
- the corresponding connector EC32-2 of the front power distribution fuse box
- the cable to the compressor
- the connector EC60-2 of the compressor
- any of the ground (earth) cables/connectors behind the headlamp (G2AR) or of the compressor (G1BS)
- the compressor itself

Be careful - I hope this description is complete.
34by151, if you are reading this, could you please check it ?

Good luck

 

Hi hawaiianjag,

the ring may look worn quickly as it rapidly rubs the cylinder but it should be polished all the way around the profile, it will be uneven as it tilts but should be a smooth polish mark around the circumference,

not sure abnout the rust bit you talk about but i dont think it is any problem, as long as it is not in the cylinder, bu in the piston rod end.

I suggest we need to check the pressure from the compressor to prove if it is ok or not, best way is to apply 12v to the main motor plug and use a guage to read the output pressure is an ideal method, it should hit 200+ psi after 10-15 seconds running, but simply a finger over the output hole will give an "idea" if good pressure it will blow your finger off the end, it is a problem if you can keep your finger on the end easier,

if compressor is bad next we check the one way valve in the drier unit, let me know what you find, and will try to help

regards

Andy

 

That will work and your thinking is sound but an easier way to test the compressor wiring is via the relay socket

1. Remove relay 1 (R1)
2. Test for Power at Pin 3 (this is fed from the 175Amp fuse)
3. Test Pin 5 has resistance to ground. This tells you the wiring via the Fuse and compressor is not broken
3. Short Pins 3 and 5 (you can use a spade plug and a short length of heavy wire)

As soon as you connect pins 3 an 5 the compressor will run

If you get the compressor to run test it again with the relay in and ignition on

If you then don't get the compressor to run it is either the feed from the ASM or the relay

You can test the ASM output with the relay. Just check pin 2 gets power when you turn on the ignition. While you are at it check Pin 1 is ground

The asm sends 12 volts to pin2 to turn on the relay
the relay coil is connected to ground on pin 1
The poles of the relay (pins 3 and 5) switch the battery power to the compressor.
Pin 3 Goes to the battery and Pin 5 to the compressor via the relay

While I think about it another tip. Replace all your fuses with LED fuses. When the fuse blows the LED lights up. I have all my fused replaced for this type and it make life simple chasing a blown fuse especally at night!!!

15A Blade Fuse with LED Indicator - Blue - Jaycar Electronics

Cheers
34by151

 

Thanks again, 34by151 !

The relay pins are labeled in the electrical guide :



and underside the relay as well :



Of course you know that you have to check the socket, not the pins of the relay.

Remember that pin 2 only gets +12V when the engine is on and there is not enough pressure in the system (the compressor has to run).

 

Yep goes without saying.

PS I never both to test relays because it easier to swap it to test that bugger around

Cheers
34by151

 

Hey Andy or anyone else that may know,

I don't have a gauge but I wanted to check the pressure of the compressor to rule it out so I can move on to other causes to my problem if it's not the compressor,
You say to put a finger on output of compressor, small 4mm threaded hole.... I can't seem to locate this output port, is it the same port that the air line connects to the compressor? So I would unscrew the airline and start compressor then place a finger on that port to feel resistance?
Or am I looking at the wrong port?

Aloha

 

Update: just got back from a trip so I'm on the job again trying to get my car to lift again...
Jacked up car, started it up. & for the short amount of time the compressor was running ( about 10 - 15 seconds) I put my finger near exhaust port and felt no air escaping from that area.
The car compressor soon after, let out a burst of air then the compressor shut off.
It gave off the same burst/let off of air as in the past when my car got to the correct level of height, it would give a short burst of air once the car got to the correct height.

This makes me remember, after the car was getting a coolant hose changed they finished the job but weren't able to get the car to lift to proper level like it was when I dropped the car off.

The shop told me the car was giving off a ride height level code when hooked up to the computer.
They said I should replace all components of air system (I laughed, then took car home riding low)
(The shop was Jaguar Indy specialist, so I assume it was a jaguar specific code)

Could the possible cause of all this be a ride height sensor?
I can see how the car may think it's at the correct level when it really has not lifted at all....
Or maybe because one front corner of the car is jacked up it thinks it's at correct height so it gives the air burst/let off?
What do you guys think?

 

Aloha Hawaiianjag,

Sorry to hear you're still having trouble.

Just a note before I forget: I was looking for your signature to remind me of your model and year and didn't see it, so I scrolled down the thread and found your signature in your post on June 24. Somehow between then and now your signature has been lost or turned off - not sure how that happens. You might check your Control Panel.

Okay, in scanning your previous posts, here's a summary of my understanding of the sequence of events, as well as some questions:

1. Prior to the failure of the coolant hose, the Vehicle Too Low message would appear when the car had been shut off for an hour or more, but when the engine was started, the car would raise within a couple of minutes. This suggests that the air suspension has a moderate air leak, but that the compressor was able to overcome the rate of pressure loss via the leak to recharge the system and maintain proper ride height.

2. When a coolant hose failed, the car sat for about a week awaiting the arrival of parts. When the parts arrived, an independent Jag shop installed the coolant hose and a new thermostat. After this work was done, the car would no longer raise, and both the Vehicle Too Low and Air Suspension Fault warnings appeared.

3. You drove the car home with the suspension sitting low. I assume you exceeded 2 mph, which should have terminated Jacking Mode if that had been prompted when/if the shop raised the car to replace the coolant hose.

Is the above correct? Have I left out any important details?

Okay, to answer the question in your previous post, yes, the outlet port of the compressor is the hole into which the air hose brass fitting is threaded. You will need to carefully unthread that fitting from the compressor in order to test the compressor output pressure with your finger. See image 7 in the photo album at the link below:

Welcome to Jag-lovers - Members Photo Viewing Page

When you reinstall the brass fitting after your test, do not overtighten it or you will damage the hose and/or brass "olive" compression fitting. Member abonano says the fitting should be tightened by hand, then tightened about 1/4 turn more with a wrench.

Finally, aside from planning to test the compressor per Andy's recommendation, have you performed any of the checks suggested by Leo and 34by151?

Cheers,

Don

 

Hey Don,

Thanks for the reply.
Your order of events is exactly correct.

I just got back from a trip and can't locate my ohmmeter to do the tests the mentioned. I also have never really messed with electronics of a car so I'm a total newbie when it comes to testing a fuse port ( I did look to see if fuse 6 was blown- it was fine)
I was thinking about swapping the R1 relay with one of the orange ones next to it to see if that does anything in the meantime...

I can't get the compressor to come on once I've jacked the car in the air so I assume I will be forced to use the car's battery to rig up what the other posters have mentioned in order to get the compressor motor to come on.
I hope I can pull it off, being as I don't know much at all about most of the lingo described.

I also unscrewed the top air line on the passenger side (has original shock), air was holding pressure as once i turned it a few times air would start to come out.
On the drivers side air hose(new, recently installed arnott), the air line nut was unable to be loosened, as I tried to turn the nut, the brass port that the air line goes into would turn with the airline nut simultaneously....tried to use little pliers to hold the brass port the air line goes into in order to prevent it from spinning so that I could get the airline free, but it was ineffective. Couldn't get it Could that be a potential issue if the compressor turns out to be pumping out sufficient psi when/if I am able to get power to the compressor to get it running on demand?

I hope I'm close to figuring this out

Thanks again everyone

 

reading over the responses again, and it doesn't sound too difficult. i just need a voltmeter, a spade plug, and a short piece of wire it seems? and how would I go about shorting the circuit/How do I go about using the "spade plug and a short piece of wire"

Thanks!

 

You will get the spade plugs at an autoshop as well as a crimper
Just crimp the plug on the wire

All you are doing is simulating the relay closing by using the wire

HT 202B Terminal Crimp Crimping Tool | eBay

50X Blue Male 6 3mm Spade Connector Insulated Crimp Terminals Electrical Wiring | eBay


Cheers
34by151

 

thanks a lot 3by151!

I really appreciate the info. and will be doing this today once I get the spades & crimper and short piece of wire.

Thanks heaps!

 

Hey guys,

So I was sitting in my car this morning after it sat for 14 hours or so and before pulling it in my garage to work on it, decided to unscrew 4 of the bolts holding the forward part of the fender liner and was able to get a 10mm wrench in there to disconnect air line,
I started car and put finger on outlet port....
Didn't have a gauge but the pressure didn't seem like 200psi would feel.
I could relatively easily put my finger flush with the compressor port after applying some pressure.... Maybe my finger pressure gauging is off but I just don't think that it's pumping much pressure out.
I really didn't feel much pressure at all until my finger was completely over the hole, then there was some resistance but not a whole lot...
Based on my description of how it was pretty easy to push finger flush with outlet port without too much resistance..... Where on the compressor should I look next? or am I better off just buying a new compressor?

Aloha

 

Aloha hawaiinjag,

I will definitely defer to Andy on the issue of whether your compressor is delivering sufficient pressure based on your finger test, but if I understand how the compressor works, it doesn't actually deliver 200psi directly from the piston/cylinder. It gradually builds up that pressure in the system one cylinderfull at a time, so it's operation is actually a series of "puffs" separated by "breaths" when the piston drops in the cylinder and fresh unpressurized air is inhaled through the leaf valve.

I'll be interested to hear what Andy and others have to say, but I'm still wondering if your system has a leak that you have not yet found. I can't remember if you've checked your exhaust valve for air flow while the compressor is running.

To examine the check valve in the compressor you'd have to remove the compressor and cylinder head again, but if that valve isn't holding pressure your compressor will run and run but some or all of the air pressure will just leak right back into the cylinder as the piston is dropping and the leaf valve opens.

You can also check all the air hose fittings at each shock and at the valve block and reservoir in the trunk. Mist a little soapy water on the fittings and watch for bubbles.

Cheers,

Don

 

Hi Don,

Thanks for the info....

Regarding the exhaust valve.... based on the picture you directed me to which described the location of the exhaust valve (half tube near/part of the electrical connector (green arrow on the pictured you referred me to) it wasn't leaking any air as far as I could tell, checked it while the compressor was running of course.

As far as the air shock fittings on top of the shocks, I was able to get the passenger side (old oem shock) brass air line nut loose with ease, and pressure was released but the drivers side (recent arnott rebuilt shock) air line nut was stuck to the air valve. Looking through another thread, I notice the air valve looks like it is also able to be unscrewed. So now I am going to unscrew the air valve to try and get some more leverage on it once its out in order to get the air line nut loosened so I can inspect/replace o-rings (any source for the Viton O-rings you guys know about?).

I would need to test with soapy water while the compressor is on correct? There wouldn't be any air bubbles if compressor isn't running I assume?

Thanks for your help everyone!

 

I know that McMaster-Carr carries lots of Viton O-rings, but I haven't tried to match up the metric sizes our X350s use. I know there was a thread in the last couple of months on Viton O-rings.

Ordinarily, the system should be under pressure even when the compressor isn't running, so you should be able to check for leaks anytime the system has been pressurized, but if your system isn't pressurizing at all, that does pose a problem. I'm being ordered to turn the lights out so I'll have to sleep on it!

Cheers,

Don

 

Thanks Don!
also... does anyone know what type/size of tool is required to take off air valve that the air line connects to on top of shock?
As mentioned, one side was stuck to air valve so was able to get it loose from the 12mm air line nut but other side will need the correct tool
want to swap out all the o-rings to rule them out
The one air valve I was able to get out already seemed kind of distorted and looks like was not replaced when the OEM shock was taken out and replaced with an arnott rebuilt, can these air valves be bought individually?

One more thing....I tightened the 17mm nut on the top of the oem shock but when I tried to do the same to the arnott rebuilt shock.... no 17mm nut? Just the electrical connector in some white grease solution? I pulled the electrical connector out of the white grease to inspect below it, is that okay? Or was I not supposed to do that?

Thanks

 

hi Mahalo,

from your desctiption it sounds like poor pressure for some reason, a good compressor you can push your finger against the outlet hole but it will blow your finger off the end after 5-10 seconds,

if the compressor output feels poor then we can check a few things 1st:

i know it sounds silly but make sure you are checking the pressure from the outlet which is the small threaded hole opposite from the cylinder end, there are 2 holes, a larger 8mm hole and small 6mm threaded hole, it is the smaller threaded hole which is the outlet.

the compressor should hit 200 psi after 10-15 seconds running so again make sure it runs for at least this time to feel this.

is their a little pressure or nothing at all?
what condition was the cylinder is, badly scored or smooth?

if definetely poor pressure, next step is to ensure the piston ring is fitted the correct way, you must be able to see the small timing pin in the end of the pistin groove, if upside down it will not work well at all. also make sure it has rub marks all the way around the diameter to make sure it is fitting correctly

next suspect is the one way valve at the top of the cylinder, see section:

Attachment 90707

unbolt the plastic drier unit from the cylinder head (2 x 10mm nuts & long bolts) and remove the stainless plate in the back of the cylinder to expose the one way rubber valve and spring, make sure it is clean and spring is intact,



if these check out ok there are a few more things to check/clean

• n11 valve leaking
• remove beads chamber and check spring is in the end,
• pressure release valve (white plastic cap has 2 springs and rubber pressure valve)
• cracks in the plastic drier body

but start with these areas above and let me know, im sure we will get it working better

regards

Andy

 

( I ANSWER QUESTIONS TO YOUR REPLY WITHIN YOUR QUOTE (---) SORRY the multi-quote feature wasn't working for me)

---- Thanks a lot for the info andy, I will perform the below inspections as best I can, when I get around to it. I can't spend much more time fiddling with this compressor as the XJR is my main means of transportation right now so I elected to buy a new compressor and it should arrive tomorrow, I still want to rebuild this one to get the pressure back to normal and then sell it on ebay to someone looking for a rebuilt compressor.

Thanks again everyone, will report back after new compressor is in and I swap out the air line/air valve o-rings

By the way, does anyone know what type of tool is required to remove the air valve so I can get to that tiny o-ring?
It has these little notches on both sides, can't picture what tool would be required to get these out?

Aloha