The temperature sender (the sensor that sends the temperature signal to the gauge) has to be immersed in coolant in order to correctly read the temperature. If the coolant is so low that it leaves the sender high and dry, the temperature shown on the gauge will not be a true reading.
if the sensor is not immersed in the coolant, there a big chance it wont read at all...
check antifreeze level
If you are referring to the temperature reading on the gauge, then it's possibly a bad thermostat.It will also read 'cold' until the engine has sufficiently warmed up.Lack of fluid (water and/or antifreeze) in the radiator.Low engine temperature (bad thermostat).Low coolant level.Bad gauge.Wiring issue.Coolant temperature sensor bad or not correctly grounded.Problem in an electornic control module.
Probably low coolant or a faulty thermostat
Low Coolant or faulty gauge
at the beginning it will be cold, but it will warm up as you start driving
Thermostat is gone, change it
Could be low on coolant or a sticky thermostat.
No! Thermostat.
check the connections behind the gauge they could pop loose
Unplug the coolant temp sensor and check what the gauge says...If it falls to cold, then the sensor is at fault. If it stays, then the gauge is either faulty or the contact points on the back of the gauges need to be cleaned... Unplug the coolant temp sensor and check what the gauge says...If it falls to cold, then the sensor is at fault. If it stays, then the gauge is either faulty or the contact points on the back of the gauges need to be cleaned...
Make sure it is full of coolant. There probably is a small leak causing the smell. Check it cold as sometimes it leaks cold but not hot.
Check your thermostat. Looks like it is stuck open and needs replacing. That could be why your engine is running cold. Atleast its not stuck in the closed position.