Hi All,
I have had a very small coolant leak since I purchased me vehicle 2 years ago. The coolant tank has never run dry even after a 500km drive but there is the smell of burning coolant.
Yesterday after figuring out (thanks to the help of this great forum) you need to pinch off the overflow pipe to do a pressure test I pressured up the system to 13-15 PSI and it held with no sign or sound of a leak. This leads me to believe it is caused by something heating up and expanding and only leaking when it is hot? I have searched while the system was hot but no luck in finding the leak.
Any suggestions out there as to what may be causing this?


Regards,
Karl

 

In my wife's 2006 XK8 last autumn, a very slight coolant loss turned out to be caused by one of the hose connections at the coolant reservoir tank not being properly seated all the way onto the nozzle. Once I removed the plastic engine dust cover so I could get a good look at the entire area, I quickly spotted a very small orange stain at that particular hose connection. So I loosened the clamp slightly, reseated the hose properly, then tightened the clamp. Problem solved and absolutely no loss of coolant since....

Remove your engine dust cover and take a good look at how all of the hoses are seated. You may find your culprit just as I did....

 

while you have the engine cover off, take a flashlight and a small dental mirror and look under the intake manifold. Mine was leaking a fine mist from one of the tunnel hoses. very hard to spot and the coolant was vaporizing so it never hit the ground but I could smell it

 

Likely hoses are the under intake heater hoses, and the large "spider" heater hose that connects to the bottom of the header tank. If you take off the trim covers, look at the bell housing of the transmission, look for coolant residue. There is a plastic valve in the middle of the hose that develops a crack, takes a very long time to leak out, very hard to see.

JAG # MJA 6728AC

 

I had a similar phantom leak. I found it to be on the passenger side above the exhaust cat at the bell housing of the trans. Follow the hose from the tstat tower under the intake. To just below the throttle body. This is where there is a norma connector is. That is where my leak was. To fix I had to take off the cat exhaust. Cut off the norma connection insert a straight pipe and hose clamp the connection on both sides. As the previous post stated use a mirror and you will see residue on the front of the cat. I will look for the post as I had pictures.

 

https://www.jaguarforums.com/forum/x...nection+repair

This is how I fixed my leak and it is still leak free to this day.
Photo's were taken with the passenger side cat removed.

This was a time consuming fix. but not really to difficult. It could have gone faster if I hand smaller hands!

Also do a search for "norma connection repair" there are several other scenarios by other members.

http://www.pepboys.com/product/detai...nlyStore=false
Goodyear Engineered Products 5/8" Heater Hose Connector with Clamps. Part # mpn 64092 SKU: 9626018