I previously owned a '98 XJ8 and have always heard the cooling fans running after driving and then stopping. I recently purchased (one week ago) an extremely nice '03 XJ8 and am experiencing intermittent coolant overflow from the overflow tank. It suddenly occurred to me that I have not heard the fans kick on, at any time...checked the fuses and they are good. Could this be a relay? And could this be my overflow issue?

 

It could be.

You could read the ECT via OBD and get a feel for just how hot it gets.

Don't let it overheat as warped heads do happen

 

Will do. What would be an acceptable range on temp? Many thanks!!

 

If i remember it correctly, atleast one of the fans should kick in with a running engine and with ac going making cold...

Problem area are ofcourse the temp sesor.. but with that one dead you, would most likely not have any temp indication on the dash..

Leaving the coolingfan control relay a prime suspect (unless no fuse is blown ofcourse)... its a dual relay thingie... that is located in front of the LH fwd wheel.. one level down underneith the ABS unit... next to the coolant overflow tank.... upside down kind of.. remove install a few times... if no help.. try with another one..

/E

 

Looks like both fans are running when the ac is on. At what point should they keep running after the car is turned off?
Why I'm asking is that I was referring to having never heard them kick on AFTER driving and turning the car off, and I remember hearing those fans kick on in my '98.

 

Maybe they just don't run anymore after the car is off? I don't remember mine ever running with the car off and warm. Both fans should switch on/off low speed when the engine is up to temp, and both fans should run at high speed when the AC compressor is engaged.

 

If you have an OBDII reader that can read data in real time, leave it connected while you drive and see what the temperature is: should run between 195 and 210 or so. Sounds like you have no real issue. My fans never ran after shutting the car down.

Intermittent overflow from the overflow tank, is another concern. What is really happening? Is boiling over to the capture tank in the wheel well, or simply flowing back and forth?

Frequently, on this forum, we find that the two black plastic hoses are not connected correctly, thus forcing coolant out of the tank at the firewall to the overflow in the wheel well. They should cross over each other; if parallel, they are misconnected -- non Jag shops (and unaware owners) screw it up all the time. OBTW, they are very fragile.

Lots of threads. Run a Google search.

 

Wow. I can not believe I didn't think of that. You are correct. The lines are NOT criss crossed, they are straight. I had the same thing happen to me with my '98 when I replaced the coolant resivoir tank and did not reconnect them correctly. One would think I'd learn my lesson, but, alas, I guess that isn't the case!
Thank you very much for the reeducation.