Xag--I went out this morning after the car sat overnight and opened the driver's side door. I did not hear any hissing. When I went on my 170 mile trip a couple of days ago, I drove to my mother's about 2 miles to pick her up. I shut the car off, went into her house for about 10 minutes, then we both got into the car. I started the car and immediately drove maybe another mile or so and recieved the ASF message. I should note though that at the end of the day, after I dropped her off and headed home, the fault message was still there. When I started the car the next afternoon, there was no fault message. I let the car idle for at least two minutes before I drove it about 10 miles with no fault message. Yesterday morning before starting the car, I also just opened the driver's door and listened for a hiss. I did not hear anything. In the past I have heard what sounds like a gush of air many times after parking the car in the garage and heading into the house. You are correct that I am contemplating the coil conversion but would be estatic not to have to put out the money for it if the problem can be solved. I have tried listening for the compressor, but for some reason, even with putting my ear next to the bumper, I am unable to distinquish it. Yesterday I listened for it and thought I heard a faint sound of air filling but not hissing after I started the car and got out and put my ear to the bumper, but I am not sure. What does the compressor sound like? My mechanic previously commented that he had never heard the compressor run either, but I am not sure how loud it is. He has never put his head down next to the bumper to listen for it. I have been told that he is a very good mechanic but I think this is the first Jaguar he has worked on.

 

Don B. Last time I took measurements the mechanic instructed me to measure from the floor to the bottom section of the car below the driver and passenger doors. There is a sectioned "line" created there that runs along the side of the car on the 05 model. I measured from the start of the line at each wheel well to the floor. Would this work? I also think one of my tires looks a little low so I want to make sure that all tires are properly inflated before measuring.

 

I will take the car out again today for a 10 or 15 mile drive. I will let the car idle for 2 minutes before I head out and see what happens. Thanks again for your patience and help.

 

Hi olypen123,

You're right to ensure the tires are properly inflated before performing your measurements. I don't know if our '04 has the same sectioned line you describe, but the Workshop Manual specifies that the ride height be measured from the center of the wheel to the highest point of the inner wheel arch of the body. Without the special Jaguar tool that centers on the wheel, it's easier for me to measure from the floor to the highest point of the wheel arch. Measuring your way sounds like it would require laying down to read the rule or tape measure... ?

Either way, just let me know the method you use and I'll measure ours for comparison.

Cheers,

Don

 

If I understand you correctly, I will measure from the floor at the center of the tire to the top center of the wheel arch? I cannot get the tires checked until tomorrow so I will have them checked, drive a bit, park the car and measure. I will measure again after it sits overnight.

 

Yes, if you measure that way, we will be able to compare measurements.

One thing I don't recall any of us mentioning before is that, at least theoretically, there should be a slight increase in ride height when the air in the tires is warm from driving any distance, and as the tires cool, the ride height will naturally fall a little. I may measure the difference sometime just to know if we need to make any corrections for warm vs cold tires in our overnight air suspension measurements.

With that in mind, I don't think you need to drive the car around before you take your initial measurement. Just start the engine, let it run for at least two full minutes (listen for the air compressor to start, run, then shut off). Shut off the engine and measure your ride height. The compressor won't run again unless it's needed, and even then it won't normally run until you exceed 25 mph, so you should get a full charge within two minutes of the engine running.

Then measure again after the car sits overnight.

One other measurement that might be interesting: Start the car and run the engine for two minutes. Measure. Start the car and run it for another two minutes and measure again. Is there any significant difference in the measurements? This could give us an idea of whether the compressor is properly charging the system within one two-minute run.

Cheers,

Don

 

Sounds logical to me. You both got in and the car was lowered a bit. The compressor tried to fill but wasn't within the time limit.

[QUOTE=olypen123;1033321]I have tried listening for the compressor, but for some reason, even with putting my ear next to the bumper, I am unable to distinquish it. Yesterday I listened for it and thought I heard a faint sound of air filling but not hissing after I started the car and got out and put my ear to the bumper, but I am not sure. What does the compressor sound like? /QUOTE]

It's not easy to hear. Usually when you start the car it is running at a fast idle. After a while the fast idle drops down to a lower idle. On my car then usually the compressor starts. It's kind of a humming sound, not sure if my discription is correct! If you keep listening you hear the humming stop and you'll hear the venting (hissing) of the compressor.

He may not have heard it but it's definitely there and running from time to time, otherwise your car would be flat on its belly!

Guus

 

GUS--Yes, that was my comment to the mechanic also that the compressor has to be working to some degree or the car would be sitting on the tires. I will take some measurements, continue with the idle test for the next few days, talk to the mechanic, and report back. I will also try and determine if I can hear the compressor and the hissing sound. Is there any other information I can provide?

 

I think it's important we establish your suspension is ok. If that's the case probably only the compressor needs replacing which is an easy job. If the suspension also has issues you have to decide on replacing parts or going for coils.

Curious to see your measurements! All for corners and before and after the night. I believe Don already suggested that too.

Guus

 

I agree with Xag. I hadn't posted anything else after stating that my issue immediately got resolved (no now fault) after replacement of my compressor. My symptoms, as mentioned b4, were close to identical to yours Olypen, but it seemed y'all were going a bit deeper in the convo. Hopefully, you have some place near you as I, that works solely on foreign vehicles (Mercedes, BMW, Porsche & Range Rover) They actually don't specifically work on Jags, but he's been servicing mine being I take my Range Rover there; just saying that to say, maybe you can find a place similar to you; I only paid $630 total & have a lifetime warranty on the compressor...

 

I went out this afternoon and started the car. There was no hiss when I opened the driver's door. I got out and put my ear close to the driver's side front bumper by the tire. I think I heard something running and also what sounded like a faint sound of air flowing. I did not hear a hiss. I listened for about 3 minutes. I got into the car and drove to get air in my tires and turned the car off. A couple of the tires had air added but not much. I then drove for about 10 minutes and returned home. I did not receive the ASF message. I parked the car and measured. Here are the first measurements: FDS: 27-7/8" FPS: 27-7/8" RDS: 28" RPS: 27-1/2." I will measure again in the morning and post. Also, I put in a call to the mechanic this morning but haven't heard back from him yet.

 

Hi olypen123,

I'll measure mine in the morning and post for comparison.

Cheers,

Don

 

Hi olypen123,

This morning I measured the ride height of our '04 X350, and I clearly need to use SDD to re-level and recalibrate our suspension, although the manual does state a ride height tolerance of +/- 15 mm (3/5") (which seems huge to me). I've been contemplating lowering our suspension per Cambo351's method, so perhaps the time has come to dive in.

Below are the measurements. Numbers in parenthesis () are the difference compared to the previous measurements. Numbers in brackets [] are the difference compared to the original cold measurements.

Cold, before starting engine, car had been sitting for two nights without being started:
FDS: 27-1/2"
FPS: 27"
RDS: 27-7/8"
RPS: 28"

I started the engine and let it run for over two minutes. The compressor never started, but the suspension rose from the air reservoir, which the ASCM apparently thought was all that was required:
FDS: 27-7/8" (+3/8")
FPS: 27-1/2" (+1/2")
RDS: 27-7/8" (no change)
RPS: 28-1/8" (+1/8")

I shut off the engine, waited about 30 seconds, then started it again and let it run for over two minutes. Again, the compressor did not start:
FDS: 27-7/8" (no change)
FPS: 27-7/16" (-1/16")
RDS: 28-1/8" (+1/4")
RPS: 27-13/16" (-3/16")

I shut off the engine and waited about two minutes. Then I started the engine and took a 10 minute drive in which I exceeded 25 mph and achieved a top speed of about 50 mph:
FDS: 28-1/4" (+3/8") [+3/4"]
FPS: 28" (+9/16") [+1"]
RDS: 27-7/8" (-1/4") [no change]
RPS: 28-1/8" (+5/16") [+1/8"]

I'll be interested in what others think of these measurements!

Cheers,

Don

 

Here are my morning measurements:

Front tires: 27-1/2 (-3/8)

RDS: 28 (no change)
RPS: 27-1/2 (no change)

This morning when I opened the driver's door, I did hear a poof of air. I started the car and did NOT wait 2 minutes (we were running behind). I drove the car about 2 miles, parked, and measured again. It measured 28-1/4 on all four sides.....go figure. Also, no ASF message.

 

Don, just out of curiosity why do you want to lower it?

Interesting. I guess because mine leaks air so bad it always need the compressor to get back up again ;-) It always runs the compressor. I'll check again what happens after installing the new shocks tomorrow.

I think these values look pretty good to me and the variation seems well within what I would find normal. Especially considering it an active suspension and the pressure in the shocks can vary a bit already causing height difference.

Guus

 

The measurement causing the ASF message is also depended on how much pressure was still in the suspension. My guess would be that this time there was enough pressure left.

Looking at the values I believe your suspension is fine apart from the compressor. Don, what's your opinion?

Now it's your choice if you'll have only the compressor replaced or take more drastic measures ;-)

Guus

 

[QUOTE=Xag;1034739]Don, just out of curiosity why do you want to lower it?[QUOTE]

Hi Guus,

I've considered lowering the suspension slightly because I think it sits a little higher than it should for the best appearance and stance. Cambo351 lowered his 15 mm, but I'm not thinking of going that far. Perhaps 10 mm in front and 5 mm in the back, if any. I'll start by re-levelling and recalibrating the suspension to factory specs before I consider doing any lowering. Maybe after I get it recalibrated I'll like it just fine.

Cheers,

Don

 

Thanks for all the help. Most likely will just convert the system and be done with it. Not 100% sure..

 

I spoke with a tech at the Jaguar dealership. He informed me that the C2303 code is for the compressor relay......and that I should replace that and see if it fixes the problem.

 

That's certainly not what the Workshop Manual says, but perhaps the technician has learned a shortcut for addressing the C2303 code? Or perhaps he is confusing it with another code such as C1830? We'll be interested to see how it goes!

Cheers,

Don