It is on the intake manifold near the thermostat.
I do believe that the oil sensor in a 1996 Jaguar tells you how much oil you have and it tells you the oil temperature.
Your engine coolant temperature gauge has a sensor ( there is also a engine coolant temperature sensor that is used for the computer / PCM )
ambient air temperature sensor - tells you the outside temperature
It is an electrical device that tells back the engine temperature to both the temperature gauge and (where fitted) the engine management system.
seriously? it tells you what temperature you engine coolant/antifreeze is. that is how your gauge on the dash knows what your temperature is at.
The best way is to find someone with a scanner that tells you what every sensor is doing.
it tells the radiator fan when to turn on
It tells the computer the temperature of the engine. That info is used for fuel and timing control, for activating the radiator fan, the gauges in the dash, etc
The coolant fan switch is located on the intake manifold near the thermostat. The fan should come on about 232 to 235 degrees and turn of at or near 195 degrees. Check on rear of radiator near top--should be plug with two wires
The oxygen sensor is located in the exhaust system. There is usually 1 before the catalytic converter and 1 after. It reads the exhaust and tells the engine control module how rich or lean the mixture is so it can get the proper air to fuel ratio.
An "IAT" sensor tell the computer on a vehicle the air temperature inside the intake. The computer then tells how much gas flow the investors need to dispense for proper air-fuel mixture.
There are two separate sensors that play here. the "coolant temperature sensor" and "coolant LEVEL sensor". I suggest confirming which of these was replaced, as it is very common for them to be confused. likely you will find the coolant sensor that was replaced was the one on the engine (temperature); The LEVEL sensor is mounted either in the coolant resivoir or in the radiator. Probably just need the proper sensor replaced.