My 05 XJR front suspension drops about 1.5 inches overnight, particularly in cold weather (50F degrees or lower). On start up it rises and everything is jake.

I figure there is an air leak someplace and would like to check it out. Does anybody have an air line diagram? JTIS says to check for leaks but gives no info except for major component location. No info on air line routing or junctions.
Any help out there on how to approach the problem and how to get an air line chart would be welcome.

 

I don't think it is a problem. My '04 XJ8 is "on the ground" every morning, but rises after starting straight away. Has done this since new.

 

Geo-- You may be right. One thing's for sure, "if you go looking for trouble you will find it". Still--------?.

 

I'm still wondering if anybody can put me on to an air line distribution diagram/chart? It seems like an indispensible item to service the air suspension system.

 

So OK. I've done the soapy water leak test on all available air connections. All good. Did not do the air compressor as it's too hard to get to and logic says thats not the problem anyway.

I'm thinking as follows: Sense it's only the front end that drops, it's not the compressor or the tank. Sense the Rt side drops a little lower than the Lft side there may be 2 issues.i.e. the 2 front air shocks leak separately.

Therefore, sense the drop any occurs only over a 36 hr period with 60 F degree or lower temps , quickly corrects on start up and air shocks are $1K+ each------ maybe I should just forget about it. I have to admit that this conclusion is based on a sketchy understanding of the air suspension system.
ANY THOUGHTS OUT THERE.

 

If I get the 2005 JTIS in the mail soon, and if its well displayed in a schematic, I'll post up the pdf for it. Sorry can't be of any more help.

 

Lincolns suffer this same issue all the time it's usually the air dryer that starts to leak or solenoid valve on the front air bags that are not closing properly. Have you checked the air springs for dry rot and or cracking?

Personally I removed the air suspension from my mark viii and built brackets and installed a custom air ride setup

 

Where have you seen something called a 2005 JTIS?

 

from BuckMR2's image hosting...

 

When the car sits overnight it shouldn't drop an amount that is visible without a tape measure check. In other words if your XJ is low in the morning after being shut of the prior evening it is leaking somewhere. The fact that it is corrected shortly after starting is irrelevant. The real problem needs to be corrected before excessive stress is placed on the compressor and an air suspension warning is displayed in the message center. Once the messages start displaying it is just a matter of time before the air suspension module inhibits operation of the compressor in a life preserving mode that is only corrected with great difficulty by a Jaguar technician with access to the SDD.

Check for leaks at the top of the front air suspension units. Look under the hood/bonnet where the air springs mount and you will see an open square where the top of the spring is mounted to the chassis proper and the air line is connected. Spray this entire area with very soapy water and look for bubbles coming from what appears to be the mating surface between the air spring and the chassis. If bubbles are coming out where the spring top contacts the chassis the spring is leaking and needs to be replaced.

The air lines just run along the side of the car to the reservoir in the trunk and should be easily traced without any type of diagram necessary. Just remove the various undertrays and the lines will be very apparent. The only line leaks I have ever seen have been accident victims. I've seen a few leaks at the connection between line and spring but those are just o-rings and compression fittings and should be easy to find with soapy water and easily repaired. I've never seen a leak at the reservoir in the trunk. There are no joints in any of the lines between reservoir and spring unless a previous repair has been made so there is nothing to check except physical damage to the lines. I have seen a couple of leaks at the main compressor line connection but this will not cause just the front to drop, it usually shows no symptoms except the air suspension fault message due to compressor overload flagging the 2308 code.

Good Luck.

 

[QUOTE=h20boy;180760]from BuckMR2's image hosting...

I have never seen this disc before anywhere. It pictures a 2007 XK left hand drive cockpit and has copyright of 2008 Jaguar Cars and says it is 2005 edition in english.

Are there other forum members using this disc? Does it load and display like say a 2002 authentic JTIS disc? Does anybody have some screen shots they could post?

Maybe I should move this to a new thread???

 

I've only see BuckMR2's postings with it...his diagrams, and layout instructions look updated and fresh, compared to my version. It's coming from the UK, so you never know...mine won't be here for several days, maybe another week. I'll find out then, for sure.

I'll send a PM to BuckMR2, and see if he can answer your question.

 

Yes the 2005 JTIS works the same as previous versions
There is a lot of new info/update info (a fraction listed in one of the pics)
Updated Main screen X Type powertrain showing link to diesel engine (bottom left) and turbo to the right of it...



Some new info/updates to the X Type section...

also new electrical diagrams for X300 (XJ6) 1995,1996,1997 MY
XJS-RANGE Electrical Guides added for 1995 & 1996 M.Y.
and too many updates for the X350,S Type,XK and X type

 

thanks for the follow up Buck. You da man.

 

I was reading an earlier post regarding some factory closeout air compressors for the Jag XJ8 04-09 series. I have 50k on my 05 XJ8L and everything is fine, but, is it worthwhile to buy one of these compressors - about $350 - now to have as a spare for the future. Is this a part that inevitably fails? Can the old compressor be rebuilt?

 

Can't say for sure if ALL of them will fail, there's always the statistical possibility it will last forever. Air springs and compressor...that's the system. Want to be comfortable knowing you've got one of those covered?

Not sure about the rebuild.

 

Yes, its 2005 v21 the last ever edition.
Maybe wrong but always thought it took a few years for copyright and legalities with Jag software CDs perhaps why its copyright 2008, or perhaps it had later updates to workshop procedures as issued up to 2008 for earler cars?

 

Thanks for the screen shots, it looks perfect. I will have to try and find one of these discs.

 

Jaguar have been supplying service exchange compressors for some time now for the XJ Series air-sprung cars, so one must assume the unit handed in is then rebuilt and sent back out again.

 

Real_Tech, here is the ebay seller where I bought mine...only seller providing the 2005 discs that I could find.