Hi group.

I had some issues with high fan speed after driving and reading this group suggested to replace the thermostat. My garage changed the thermostat, and while I was at it I asked to replace the water pump and the cooling temp sensor as well. The car was fine for a couple of days, but then my fans again was running after driving. Now at lowest speed and for 30-60 seconds after turning off engine. Fear of overheating reading this forum again said that the temp gauge in dashboard does not show "bad" temperature's before it's too late (ie going to red). I then purchased a Bluetooth OBDII adapter with Torque app, and this reports a quick rise to 96 celsius (204 F) and is steady at that temperature.

My question is, is this normal or is it on the high side? Can the garage have changed a faulty thermostat? Bad temp sensor? I would really appreciate your views before I make any claims :-)

Thank you very much in advance.

 

204 is pretty normal for the xj8, the fans only come in high at about 220 or so.

 

+1 on above.

For reference, my 4.0L N/A runs lower 88-95C on low demanding highway rides in 20-30 degrees outside temps, and goes up to the 95-105C area on low speed mountain road climbs in hotter weather.

I should monitor the temps for a bit next time, once you shut off the engine (keep the key in pos. 2).

Also check for any residue air left in the hoses, although that should have been dealt with by the thermostat if properly fitted.
Burb the hoses, re-check the level.

Last culprit could be the expansion tank cap, they are known to loose pressure keeping, but that should result into a low coolant level and a warning.

Last: the fact u have temp. readings in your OBD2 rules out a faulty temp. sensor.

 

The low speed fan comes on at 204-205 F and it's normal to have it run for about 30 sec.