I recently had to replace my radiator, while I had it apart I went ahead and did the water pump, thermostat and did the ZJ fan clutch upgrade. My normal operating temperature before was around 210 now it is down around 155 to 160. I could not find the info so I installed a 180 degree thermostat rather than a 195. Is it normal to see that much of a drop in temperature ? I also noticed that the aux fan is not running which makes me think that the temperature drop is the reason ? Thanks.

 

210 is normal operating temp, and the aux fan only kicks on when it needs to. It basically hits a certain temp, kicks on, and then shuts off when the temp comes back down to a certain degree. You drop in temp is probably from the 180* thermostat, plus if the mechanical fan is pulling more air than stock it will drop it even more. The reason for the temperature rating on thermostats is to regulate when they open. It basically keeps the coolant in the engine until it hits 195*, then lets it flow into the radiator and keep it between 195 - 210. This is where the engine is most efficient.

The 155-160 temp you're seeing might not cause any driveability issues, but expect your gas mileage to go down. The ecu will dump more fuel trying to bring the temp up.

 

Thanks for the answer, I have only driven a little bit locally but enough to get it up to temp as far as what temp is now. I was more concerned about creating bigger issues, the fuel consumption is not a huge deal since it is pretty much only used on the weekends to hit home centers and the landfill. I am also have a fuel pressure issue so that is already giving me a little bit of MPG loss.

 

I only use factory 195* stats.

 

Yup you need the 195 for it to run properly not just the temp but for the proper fuel mix from being to low.

 

Thanks for the feedback, I picked up a 195* this afternoon. Weather permitting it is going in tomorrow.

 

195* thermostat is in and all appears to be in working order. Thanks for the tips.

 

Cliffy,out of curiosity what brands were each temp thermostat?