Abnormal engine temperatures on 1995 YJ 4.0

[rekaller]

Hi Wranglers : I have my '95 4.0L YJ which has new thermostat installed, but the engine seems to be running at low temperatures even after i drive it for 50miles. Usually afaik the temperature while running should be around 90 degrees celsius but mine stays at around 70-75 celsius. I also think that fuel consumption is a little bit more because the engine is running colder than expected. What could be the reason? A guys which owns also jeeps was telling me this is normal for 4.0 L since it also has A/C and the cooling system is made in such a way that this is normal. Now is this a well know fact? but if not then what could be the cause? faulty thermostat or?.Thanks!

 

[Gilaguy23]

You should use a 195 which is 90ish Celsius thermostat correct? A couple of things., The new thermo was mis boxed, did you see the 195 on it? you sure its installed correctly?, and lastly jeep gauges are not known for accuracy. Was this a all was fine until the new thermo went in? Make sure all your grounds are good as well.

 

[machoheadgames]

Sounds like the thermostat you got is faulty, I would swap it again. The thermostat is the only part that can cause over cooling, by being open when it shouldn’t be.

And yeah, as pointed out above, make sure the gauge is actually accurate. If it was accurate before and now it’s reading low after the thermostat, then probably a thermostat problem.