Hi All,

I loaned my jag to my daughter for a day or two and while she had it, it started "squealing". I wasn't around so I don't know what or where it was squealing but when I got to the car, I was gettng a "Air Suspension Fault" From reading the forums it appeared that the first order of business was to replace the compressor/pump. I did so, and it still gives the fault. But, I have not heard any further "squealing". I drove it home and the suspension felt a little soft, but it did not feel like the system was out of air. When I took the compressor off, the line was still somewhat pressurized. Visually, it appears that the right rear is materially lower than the other three quarters. When I cranked the car, I could hear a hissing sound on that wheel. I was hoping that it was raising the right rear, but it doesn't appear so. Also note... I am getting two other faults now. "Left Side Repeater Fault" and "Parking Brake Fault" Perhaps the parking brake fault was the source of the squeal, but my daughter said it would squeal as she cranked it...and occasionally during driving. I drove it 30 minutes today and didn't hear a squeal. I know there is a lot here, so how about we address the air suspension fault. What would make the right rear quarter low? Is it the air shock on that wheel? Should I abandon this and go to shock conversion kits like this :https://www.strutmasters.com/product...hoCDIgQAvD_BwE ?... VIN Attached in image.

Thanks in advance!

Robby

 

It sounds like either an air line leak to the strut or that the strut itself is leaking & needs replacing. Personally, I don’t like air suspension & changed mine over to conventional coil springs & shock absorbers. As you have just replaced the compressor at vast expense, it is probably better to fit a new pneumatic strut if required. Originals from Jaguar are horribly expensive, but others are available for about one third of their price. Best of luck. Craig.

 

Hi Robby,

Welcome to the Jaguar Forums! It's great to have you with us.

I edited your thread title to correct the model year of your Jaguar. According to the VIN, it is a 2004 (the first model year available in the U.S.).

The most common cause of squealing sounds at startup is a slipping accessory drive belt or a failing harmonic damper. I am not aware of any failure mode of the air suspension that can create a squealing sound, so the sound and the Air Suspension Fault are probably unrelated.

The most common cause of one corner of the car not raising is an air leak as Craig described. You stated that when you cranked the car, you could hear a hissing sound from the right rear wheel. Do you mean you could hear hissing after you started the engine? The air compressor does not run while the engine is cranking but before the engine starts.

The compressor will typically come on shortly after starting the engine, and as long as the transmission remains in Park, the compressor will run for up to 2 minutes to repressurize the system. Once the transmission is put into gear, the compressor will shut off and not run again until the vehicle speed reaches 25 mph.

You can test for a leak at the air hose fitting on top of the right rear air spring by spritzing soapy water around the brass hose fitting. Take care not to get water on the electrical connector for the ECATS adaptive damping electrical connector. Bubbles in the soapy water indicate an air leak. To test for a leak in the air spring bladder requires either a pressure gauge setup or a means of injecting pressurized air directly into the air spring. But your ears may be able to confirm an air spring leak by starting the engine and allowing the compressor to run until it shuts off, then listening at the right rear wheel well for the hiss of leaking air.

If you confirm a leaking air bladder, replacement units are available, but they should really be replaced in pairs since having one new shock absorber and one old, worn shock absorber can lead to vehicle stability issues, especially during an emergency maneuver.

I have installed several of the Arnott Industries coil conversion kits, and recently installed my first Suncore kit. Both kits provide a very nice ride with somewhat more body roll, dive and squat than the stock air suspension. Many owners are happy with the coil conversions. I personally prefer the air suspension when it is working properly. I have installed new Bilstein air spring/dampers on a couple of X350s and the ride and handling are absolutely stunning - world class even by today's standards - and the Bilsteins preserve the ECATS adaptive damping and the self-leveling capabilities.

Your Left Side Repeater Fault may be a blown bulb or a common issue with corrosion on the bulb socket in your left side turn signal repeater lamp.

The Parking Brake Fault can be caused by any of a number of problems, including low battery voltage. You may just need to re-calibrate or reset the EPB (Electric/Electronic Park/Parking Brake). To do so:

Disconnect the battery negative cable for 30 seconds then reconnect, or remove the EPB fuse for 30 seconds and reinstall
Start the engine
If the Instrument Cluster shows a message such as NOT CALIBRATED or APPLY FOOT AND PARKING BRAKE,
Firmly apply the foot brake pedal 5 times
Lightly apply the foot brake and hold
Activate the park brake (pull up on switch)
Release the park brake (push down on switch)
Release the foot brake
Confirm the warning lamp and any other previous messages are no longer displayed
(If the above does not work, try again with the last step being to operate the brake switch Up - Down - Up)

Cheers,

Don