I have only recently joined the forum and looked at a great deal of posts about water entry and air suspension issues on the XJ8 series (2004 - 2009). Not suprisingly, mine (2007 XJ8) recently started showing "air suspension" fault and based on all the posts on the subject, I started thinking of shock and compressor replacement. However, and this may be where I am way off base, but I also have a sagging roof liner above both front sun visors and also between the driver side driver and passenger grab handles just above the B pilar (centre one if I am wrong on the A, B, C, pillar thing). Again, many posts on headliner issues with Jags.

Anyway, I got to thinking, could it be the sun roof drain tube blockage/crushing problem causing overflow onto the headliner. So, last night I did the water bottle test. Opened the sunroof and poured water into all 4 corners and low and behold I only get 3 puddles. The rear driver side drain tube did not drain any water. I then parked the car so that it was tilted toward the driver side rear and pured water in again. Nothing at all came out, but the water appeard to be draining from the sunrof drip tray, so where was it going? upon investigation (pulled off the rear door seal) water was draining through the headliner and down the back pillar (C pillar?). I will cut this short at this point. After much removing of handles, rear stop light and back pillar I was able to feel the drain tube and it is still connected to the sun roof drip tray and appear to be in good condition and not crushed. Without further investigation I suspect a blockage at this point. I manageg to feed a nylon weed wacker filament up from the bottom of the drain tube (behind rear wheel) a couple of feet and then it stops dead (more investigation required). Sorry, to get to my point, if the drip tray of the sun roof overflows and the water travels along the headliner and down the rear C pillar there are an awful lot of electronic assemblies and conectors in that area. also the water is going to make its way to the lowest point and god knows what it touches or collects on/in on it's way.

Does anyone know if there are connectors in the rear passenger side of the car (c pillar, behind or underneath rear seat, floor area etc.) that could trigger air supension error codes if they got wet or corroded?

My next move is to try and get more acces the the rear sun roof tube where it connect to the sun roof. Not much room without removing the whole headliner. If anyone knows how the front centre console in the headliner is removed (the one with the courtesy lights and sun glass holder) it would be a great help. maybe it stays in the headliner, but I am not sure and would not like to try a pry it loose if it is supposed to stay in place.

Sorry for the long post.

Andrew

 

The attached page is from the phone fitting instructions and shows the console being pulled down from the edge closest to the windscreen. I took mine off a couple of years ago when I somehow managed to lose a pair of sunglasses inside it!

 

Congratulations on your logical investigations so far!
I think it's unlikely that the sunroof drain blockage is causing the air suspension fault.
If you google ''Jaguar x350 Technical Guide'' there are diags there showing location of modules, connectors etc. and I know that the ASM is located behind the rear seat armrest.
If you are concerned about the air suspension fault read the codes and if you get 2303 I would say that the compressor is your first suspect You did not say number of miles on your Jag?

 

Thank you to U102768 and Meirion 1 for the responses. Mileage on the XJ8 is a tad over 42,000. I have just returned from looking at the driver side rear sunroof drain tube. I managed to get at both ends (not difficult at all). Basically, if you take off both roof grab handles, the door seals (driver and rear passenger) plus the c pillar and the rear window stop light, the rear headliner drops sufficiently to see the rear drain tube and pull it off. I also removed the driver side trunk liner to get access to the other end of the drain tube. This end of the tube runs behind the DVD player and down to a 90 degree rubber fitting that goes through a panel behind the rear wheel. The tube can be pulled from the fitting and you now have access to both ends. I blew compressed air through and although air did go through, the back pressure was quite high (not measured, but judged). I then took some weed wacker nylon line and pushed it through the hose. It did not go through easily, but did mange to get it through from one end to the other. What I found was that the drain tube has low spot just after it comes through the rear parcel shelf into the trunk and this is where all the restriction was. My guess is that all the grundge, settles there and dries out if the car sits for any length of time. Next time it rains, given that the water is not under pressure a little more grundge settles there under gravity. this cycle repeats itself until you get blockage. Once I had cleaned out the line (lots of hot water) and the flow was good I attached the drain hose back up and did a water test. Another interesting point here, I did get overflow and not leakage. basically the drain hose can only flow so much water and if the water entering the drip tray enters faster than the hoses can flow then you get overflow into the cabin even if the hoses are not blocked. Moral here is to hand wash and not go to an automatic high pressure wash. I will now watch for the Air suspension fault and keep everyone posted.

Oh and one more thing, having done this, I won't be as scared about taking the whole headliner down to recover it - I don't think it is as big a deal as I had thought. Wonder how many headliners have been ruined by overflow from the sunroof drip tray? I guess the seal around the sunroof glass lets too much water in for the drip tray to cope with.

 

I just dropped my 2004 XJ8 off at the local Jaguar dealer because of Air Suspension Fault codes. The car was riding lopsided (left to right), the driver side front end riding on the wheel and the passenger side rear end riding up in the air – very uncomfortable ride to the dealer. It was all quite comical (unless you’re the driver)!

The dealer cautiously prepared me for a $1600 bill if they had to replace the Air Suspension Shock on one of the wheels. (If they had to replace all four, I would just open a vein!).

Within one hour of leaving the car, they called me back to inform me that it’s not the Air Suspension at all (insert my dodging a bullet grin here).

But the culprit is the aforementioned drainage issues with the sunroof which causes (or allows) moisture to settle under the rear seat where there are sensitive electrical connectors.

Cost to repair the moisture issue is $480. Cost to remediate the drainage issues so that it doesn’t happen again - $850 (insert wipe that silly grin off our your face sneer here)!

 

We live and learn.You seem to have a competent dealer.

Glad I haven't got a sun roof.

 

Sorry for not being on the forum recently (aging mum issues, but still here at 92) Anyway, finally got my back seat out and found a LOT of water under the seat on the driver side. Did find 2 multi pin connectors under the seat on the passenger side, but these appeared dry. Have left the seat out, with the sound deadening material lifted to dry out the driver side. Will let you know if suspension is impacted either way.

AWGY