Coolant leak ... Baffled.
On my 2005 XJR on the upper metal crossover above the super charger pulley snout is the temp sender and then two small maybe 7mm hoses next to temp sender. One next to sender goes to back of motor somewhere and the other goes to upper side port on overflow tank. My Delima..... I thought leak was from temp sender unit but when I blow everything dry it seems to be coming from the hose spring clamp next to it that goes through intake to back of motor.
I can start motor, heat up to temp, move hoses and things around and NO Leaks .... then go drive and sometimes still no leaks ..... then all of a sudden it shows up. I'm good at trouble shooting BUT this has got me stumped.
I first thought it was thermostat that would leak through after it heats to a certain temp, but got a mirror under inter-cooler hoses a can see my Dex-Cool dripping off spring clamp of small hose. Could the metal housing be cracked .... but why isn't it leaking under full temp and pressure ..... all the time???
My personal opinion is there must be a hairline crack in temp sender that is spaying over to adjacent hose. Cuz to me ... a hose is gonna always leak.
Any thoughts on this would be appreciated.

 

Process of elimination.
I replaced the temp sending unit along with a new compression seal.
Still Leaking .... from hose area next to sender.
Do the pressed in nipples that are in the aluminum hosing for these hoses ever start leaking?
Dealer film only show one hose fitting next to sender. Mine has two fittings for hoses off this crossover.
Any HELP on this from any one with experience of this???



under >Engine Cooling System>><br/>249 Water Rail and Thermostat>> 8005 Thermostat and Water Outlet

 

FOUND IT the overflow tube coming off the water rail had softened up and ballooned out right at the spring clamp and had developed a pin hole in it,
It only leaked under certain conditions. Have a new one arriving today.

 

Hi dwdooley,

Sorry for arriving late to your thread, but congratulations on your successful diagnosis and thank you for reporting the resolution. This will help other members in the future.

Cheers,

Don

 

Since you have one hose that ballooned, something else to keep an eye on are the coolant hoses in the engine valley that deteriorate as well. Check on those, they're a well known issue on the supercharged engines. The naturally aspirated also have hoses in the valley, but far less involved to change out.