Hi,

I recently bought a 99 XJR with 121K for a good price. I have driven the car (which has a few ****ly 10 year old car flaws) about 4500 trouble free miles.

2 weeks ago I was on a short (160 miles) trip and the "low engine coolant" warning came on. I immediately hit an exit and checked it, It was not very low at all, but I topped it with Jaguar coolant, and the light went out. I proceeded on my way.

About 15 miles on the light came on again. I noticed the temp guage swinging up. I was in a bad place nowhere to get off. The needle reached over 3/4 right as I was able to pull onto a shoulder. I popped the hood and the top hose (the "j" shaped one) that runs around the supercharger was leaking. I cooled the car off, refilled with coolant mixture, started the car and drove to safety off a nearby ramp. It started to overheat again, but I was off of the interstate and safe.

I came back and trailered my car to a nearby friend's place. I went home, ordered the busted hose and a thermostat. I returned and installed these parts. The car starts and runs smoothly, but steam comes out the right exhaust pipe so I know there is water getting in my exhaust. There's no water in the oil, and the car starts and runs fine, get's up to temp and stays cool, but I don't know what could be the problem. I thought maybe a head gasket, but have been told there are other simpler items that can cause this. The car does not leak coolant anywhere. Thanks for any suggestions. I love the car, have always dreamed of owning one, but would have to sell it if it's going to be excessively expensive to fix.

 

There are 2 things that would do this
1 internal intercooler leak, never seen it, but possible
2 blown head gasket, most potential after overheat, not common but most likely
recommendation, if youre not loosing alot of coolant or any, keep your fingers crossed and pray it doesnt become a problem

 

Funniest thing man! Just yesterday i took about a 120 mile trip in my 1999 xjr from Millsboro, de to Washington DC. it was a good 98 degree day yesterday. i admit i was doing a good bit of 95mph most of the way but everything was fine. before i left i topped off the coolant. however 2 and a half hours later i get to washington in the middle of the city cant find parking then i pull into a parking garage and the guy who checked out my car before i went in because of sercurity reasons he told me i had a leak. i was like what? must be A/C. he goes no man you def need to check this i was like alright and come to find out coolant had spilled out everywhere!!! my temp guage was fine the whole time. so i turn the a/c off continue down into the garage and park and turn my car off. there's not a drop of coolant coming out! at this point im like great my car is broke in a DC parking garage im stuck in this crappy city. So i went to some museums with my girlfriend and went to cvs and got 2 gallon jugs of water. came back filled it up turn the car on everythings fine. no leak. nothing. for safety i turned the air off the whole way home but i cannot come to think of what this could be.