Hello folks, I have noticed that my cooling fans are working at an extreamly high rate after driving. My temp gauge is fine at mid section always. However after pulling in at home after work on or a red light the fans are blowing like mad. Cooling water level is fine and engine runs perfectly. Any ideas what I should check for... Thanks much,
Rique
1998 XJ8.

 

Rique:
The fans have two speeds. It is not unusual for them to run at high- especially if the AC is / has been on. Are you sure that maybe a blade is chipped, or a bearing is starting to raise a roar and that's what you hear?

 

Another thing to check is the water pump. If the XJ8's use the same OEM plastic impeller water pumps as the XK8's, the vanes will disintegrate over time, and especially if the engine overheated, and will run loud and long trying to circulate the water and bring down the temperature. These higher than normal temps are also very destructive to the plastic bodied secondary tensioners.

 

Thanks for the replys. I opened the hood when the engine was running and those fans were turning like fighter jet turbines. I beleive that my water thermostat is not opening correctly and need a changing. What do you think?
Rique

 

That is possible, however, usually when most thermostats fail they close and the engine temperature would shoot upwards. To be safe check both the thermostat and water pump.

 

Max, how can I check the water pump? Enrique

 

According to the JTIS the fans have to be removed to get the water pump out, which is probably a pain. However, the thermostat can be checked quickly by seeing if the engine temperature goes up. If it doesn't, the thermostat is probably bad. Check that first as it is the easiest.

 

Max, temp does go up to mid gauge and does not move no matter what. I will change the thermostat and give the pump a look not much more to check. Thanks Enrique

 

If you have a chance check E-bay for the JTIS CD. It gives the complete step-by-step directions for most repairs with diagrams and drawings. The types of things that are difficult to explain with words.

Good luck.