1995 4.0 XJS Engine Temperature
So after replacing my temperature sender unit my XJS doesn't have consistent temperature when running. I purchased a replacement thermostat but once the old one was out it was slightly different, it had a larger base. I replaced it and refilled the coolant.....started the engine and it ran really hot. The top hose didn't appear to have much water in it and it wasn't that hot even though the temperature gauge was showing right of "normal". I took the thermostat out and refilled again. The engine runs a little cooler but still not consistent. I then attached a OBD II monitor and the engine temperature was around 140 after a 5 mile run. Is that about right? How do you know if the water pump is working properly? I checked the radiator and it appears very clean. The coolant was nice and green.....and ideas? What else could it be, or is there nothing to worry about?
Your thoughts please.