So I have had my 05 XJR for 10 years. 125K Miles. Jaguar Racing Green with X358 front and rear bumper covers, small supercharger pulley, Caldoofy intake. No Catalytic convertors, Center mufflers replaced with a magna flow X-pipe muffler, Mercedes Coolant Pump upgrade and a ford 8.0 posi rear diff. Its a been great car and reliable powerhouse to drive. I made the cardinal sin and drove t through a touchless car wash.
The dash board lit up like a Christmas tree. dash gauges went dead,, park brake fault, transmission fault and the car would not shift out of first gear.

I drove it back to work office and let it sit. It was a warm 78 degree day so it dried out and returned to normal with the exception of the check engine light on, my code scanner will not produce any codes but can clear them. All is good and back to normal. My question is what is getting wet to create this issue? The throttle position sensor? ECU Plug? This happened several years ago when I got caught in a severe down pour. But like this week, it corrected itself. Any input on where i need to look to correct an issue?

Thank you, Wooford XJR

 

We know that the ECU can get wet when the drain under the cabin air filter
becomes blocked with leaves.It may be that in a car wash the flow of water
into the cabin filter area is so high that the damage is similar.

 

I think meirion1 points out most likely cause, but just in case...
- Check under rear seat and make sure you don't have accumulated moisture that would short out something on the CAN bus.
- Likewise, check in the trunk at lowest point (around air compressor) for same
- Do a search in X350 forum under "AC Drain" - the ac condensate drain has caused innumerable grief for many - and I routinely clear mine ever oil change using a long flexible plastic rod about the diameter of a coat hanger wire.

 

Pollen filter out feel if it is wet on the bottom . There is a drain hole at the bottom of that box try if water is draining quickly.
JUST Below rear window under neath the LID those seams might let some water in wich is flowing inside over the wheelwell to those snake line then in to the sparetire area where the ssme for the rear Lights where water runs along the seal and lets water in to the boot
the compressor is in the front left infront of the tire hidden behind the bumpershroud/ wheelwell . In the boot is the airtank

 

Follow and work through "water ingress TSB" - main suspects is clogged drain by pollen filter and/clogged sunroof drains.

 

When cleaning out drain lines I now use weed eater line. Its flexible and less likely to cause damage. I blew the front driver side sunroof drain hose off once using air pressure and didn't find out until I had a leak down the A pillar. I then had to lower the headliner to reconnect the hose and zip tied them while I was in there. Haven't had a problem since.

 

I tried with pipe cleaner stick

 

I checked the cabin filter. All is dry. Have not noticed water in the spare tire well either. I hand wash the car and have never had an issue. Will keep checking other areas and stay out of the car wash for now. Will update all if I find anything..

Thank you Wooford XJR

 

My 2006 XJR has developed an issue after rains. Electronic parking brake locks down. Car has to dry out for a couple days before fault will clear.
Cabin filter housing is dry and drains clear. The trunk well is dry, no sign of water isn floorboard. Pillars, or headliner.
Will dig deeper to see if the issue can be eliminated or at least identified.