When taking the interior out my XJ8 for welding work I found the carpets were damp in the front passenger foot wells (UK, RHD). Using some water colour with drain dye I have confirmed where the leak is.

I poured water into the screen drain, the big hole to the left of wiper blade shaft. I was bit surprised to find that it seems to drain its contents down the transmission tunnel, between the alloy heat shield and the floor pan.

I would have thought Jag could have had some kind of drain tube ! Or is something amis with my vehical ?

I did have a similar damp problems on an XJS I had in the same area but never managed to work out where the leak was.

I also traced a small dribble of water to the foot well as shown in the photos below. Its realy hard to see it as you have to lye on your back with head in the foot well and look up between the bulkhead sound insulation and the side the transmission tunnel. However once there it seems the water is seeping through the join between two panels in that area. It actualy seems to seeping through the mastic used to cover the join. This probably means it will be rusty under the mastic.

Where the water goes in :



And where the leak is :



Look up behind the insulation, sort of towards where the rear view mirror would be :

 

I've come across sunroof hose drains being either blocked with debris or off the sunroof assembly all together causing leaks in the foot well. Be sure to check out all 4 sunroof drains as well just to be sure...

 

My vehical does not have a sun roof so I am not sure if this affects anything. I did however notice when working behind the wings I had a steel tube sticking out with a red bung in it (see pic below). They seem to point towards the front screen pillars which would inturn lead to the roof.

If the red bung is in the sun roof drain then it was sealed at the factory, presumably because I don't have a sun roof.

 

The most frequent cause of water in the front footwells is the A/C drains blocked or detached.

Could it be this or do you suspect you've got a leak at the body seam arrowed in the second pic?

Graham

 

Bang on, the red bung is the sunroof drain - the front screen drains into the tube you see, my money would be on that one being blocked, or the connection it slips onto.

 

I am fairly confident its not the A/C as its not been on for a couple of weeks or more. Also I used "drain dye" in the water I poured in and this is what leak out of the join. I got the wife to pour the water in while I had my head in the foot well and the join welled up with blobs of water as I could hear it running down on the underside of the car. If you look carefully at the pic you can see a steak of the dye running down from the mastic joint.

I have seen water come out of the rubber tubes that drain through the wheel arch liners as when I was painting in there I had them tied up. When I realeased them the following day after some overnight rain water ran out. Also I have just tried blowing through them and they don't seem blocked.

However I hav'nt been able work out yet how water gets into the rubber tubes. Where ever I pour the water into along the drain in front of the windscreen it allways seems to run through the centre somewhere and down and out through the transmission tunnel. Also tracing those rubber tubes into the engine they seem to go into the screen drain area but at quite a high level, so I can't understand when they would work as the water always seems exit through the lower level in the centre and thence down the transmission tunel.