Hey everybody!
My 2001 Jaguar XJ8 Vanden Plas is experiencing a rather large coolant loss near the front end of the engine toward the front of the car. I had the thermostat housing upgraded a few years ago and it doesn't appear to be coming from there. There is no coolant in the valleys behind the tower. The leak seems to be coming from somewhere between the tower and the front of the car. The weather has been very poor lately and haven't been able to get a good look, but I can't see where it is coming from. I found a video on YouTube talking about a coolant cross over tube where he was experiencing a leak. I'm hoping this could be my issue. Are there any other common problems in this area that I should be looking at? Here is the YouTube video I found:
I have an identical parts car to my daily driver, the parts car is in fantastic shape, so whatever the problem ends up being I plan on taking the parts.

I look forward to hearing what you may think it is!

Attached a picture of my parts car (left) and my daily (right) .

 

I'm in a similar boat w/ a smaller leak, I did the t-stat housing & crossover pipe in July this year, but not the lower hose. My 1st plan of attack is the ever trusty pressure test.

RobertDIY has some excellent Jag vids, plus he's a Steelers fan so win/win.

 

My Harbor Freight pressure test kit has found several leaks, definitely worth the investment. The crossover pipe and water pump are both strong possibilities and should probably be replaced a a piece of preventive maintenance, since they are both inexpensive.

 

I broke my bleeder line whilest doing my housing etc. I suspect my jerry rigging of it may be the culprit. After all it was done in 100 degree FH heat coupled w/ 95% humidity. I think I did well, considering my BAC was in the high double digits lol.





Either way I'm going to replace both bleeders & the lower hose.

 

Thank you for all the tips. I went out there before the rain started picking up but still couldn't pinpoint where the leak is. I took a video and a picture showing how wet everything is. It appears to below the thermostat tower, so would this be the waterpump? I can't see anything actively dripping, it's just pooling down below and then dripping to the pavement.

 

There generally is a weep hole on the bottom of the water pump that lets coolant drip as it leaks pass the water pump internal bearing seal along the line of it's rotating shaft. I don't know if the X308 has one but wash and dry the area and look for drips from this area as the coolant is pressurized .

 

Hi holybananas,

King Charles, RJ and Lady P have already given you the most likely suspects. I just wanted to chime in that I would think twice about using the old water pump and crossover pipe from your parts car. These are not only wear parts, but they suffer from age regardless of mileage. I'd hate to go the effort to install them, only to find that they leak immediately or in the near future.

The Airtex AW4124 waterpump appears to be the same pump Jaguar now supplies as a replacement, and it's available for less than USD $35 from Rock Auto. The pump comes with a paper gasket, which I have used successfully on several Jags, but if you want the OE-style metal and rubber gasket, the Mahle/Victor Reinz K31850 is $13.86. Note that the pump you buy should have a plastic impeller to endure the Organic Acid Technology coolant (Dex-Cool), which does not protect metal impellers from electrolysis and cavitation erosion.

The crossover pipe is available from our forum sponsors SNG Barratt, Coventry West, Welsh Enterprises, and Jagbits.

Cheers,

Don

 

Thank you to everybody who helped me diagnose the problem with my car . Also thank you to my dad who helped me fix it. It was indeed the water pump! Good as new.