Can anyone tell me why coolant comes out the overflow when driving? It stops at idol. Then after going on errands around town the radiator acts like its boiling but only after I shut down the engine. Then a gurgling noise and out comes the antifreeze. I have changed the T Stat and filler cap. New temp sending unit. Today I topped off the fluid at the cap over the water pump and started to drive but noticed the overflow was leaking. At idol it stops. Then drive it a little pull up the driveway and there is puddles or a trail of water following me up the drive way. I'm just about going nuts. What keeps the water in the system? There are two lines going to the over flow tank and neither look like there is any kind of valving on them. I had the car at an incline and when I was filling the cooling system and water came out the overflow. This to me inst right. TIA

 

check the lines coming out of the reservoir on top. they should criss-cross. The very top line goes to the overflow tank and the next line down goes to the top of the radiator. Its easy to get em backwards. hopefully thats all it is...

 

If you look at the tank from the grill. There is a line on the left. It goes to the bypass over the T-Stat. The one on the left front goes to the radiator and the one on the right front is the overflow. Is this how they are suppose to be?

 

no sir... switch em. I used a very small flathead inside the groove on the hose clip and wiggle either side till its free. My 03 xj8 did the same thing. thats why I got it cheaper! spent a day here on jaguar forums and all fixed. Something else I learned was that jaguar used to use a plastic pulley on the timing chain tensioner and a plastic impeller on the water pump. Idk if you switched em or if they have been changed but those were two things I looked into on mine.