Recently I have noticed the fans running on for a minute or so after shutdown. No indication of overheating, and coolant is full.
This has occurred on a cool day, after a fairly short run.
I can smell coolant, but can see no leaks. Using my laser thermometer everything I check reads under 200 degrees.
Any ideas?

 

My '97 does the same thing. I believe the fans keep running until the engine cools down to a certain temperature. I get no coolant smell so that might be a separate issue.

 

If you smell coolant but cannot find the leak, your best approach is to do a cooling system pressurized leak test....

 

Bit weird, my fans have never carried on running once the car has been turned off even in the 40C temps we had a couple of weeks back in the UK.

 

Hm, maybe I have a problem I didn't know about because if I drive mine for a while the fans will run 15 seconds or so after I turn the car off. It did this with my old engine as well as the replacement one. I'm an old wood tick and know virtually nothing about these cars other than what I've read on the forum and what the mechanic tells me so maybe someone with more knowledge will chime in.

 

Oz,
Similar behaviour from my car, and appears to be as designed. See this post from zray:
https://www.jaguarforums.com/forum/x...9/#post2402610

 

My 98 does this but then again its been 100F-107F deg every day past month so I havent worried too much about it.

 

This is something that is meant to happen on very hot days..
BUT it can also happen if one of the fan fuses has blown

You have a fuse for the low speed fan and one for the high speed fan

This was happening to my 2001 xkr and after i changed the blown fuse its never happened since.

 

Should run on at low speed after shutting down ..its an ECU-controlled function

 

Its worth bearing in mind that the cooling fan system was revised for the 4.2 engines, changing from conventional off/low/fast operation on the 4.0 cars to a continuously variable PWM fan speed controller on the 4.2. In other words how the fans behave on a 4.0 car might not be directly comparable to the behaviour on a 4.2 car.

 

I am now convinced the fans are merely the symptom of a failing water pump. Car now overheats with just a few miles of running.
Ordered a new pump and thermostat from Rockauto and will advise results.
Thank you for all the good ideas!

 

Same behavior on my 1997 XK8. Seems normal at 100+ degrees here in central Texas.
Dennis

 

Sure has Been a Hot one this year Dennis!

 

Ed,

If your car never did this before, maybe it’s just a sign that the cooling isn’t as efficient as it used to be.

I had my XK8 in the summer heat of the Middle East. Fans would run on all the time after I switched off. However during my overhaul, I refreshed the entire coolant system, new hoses, cleaned the radiators, and put in new coolant. In the coolant reservoir tank, there’s a sediment trap in the bottom - you’ll be surprised at the crap that comes out when you clean it.

After all my work, the fans was still running on but alot less. So I would guess that the fans run until the coolant temp sensor reads a certain value.

 

Decided to replace thermostat first.... easier job. Problem SOLVED! And, now I have a spare water pump.
Thanks for the many thoughts!