Thermo plunger | Function of thermoplunger in Diesel Cars

thermo_plunger

Thermo Plunger is an additional electric heating element that warms up the coolant that passes through the engine and then to the heater core that warms the passenger compartment .

The word thermoplunger derives from the french word thermoplongeur, which means immersion heater. As the name indicates, the device thermoplunger will be immersed in a liquid like oil or water and is used to heat the liquid.

It can also be placed in between the circuit where the liquid flows , so that the liquid may pass through this device so that the liquid gets heated. This device has a sole application on modern day automobiles specifically cars. You can see thermoplunger device in car cooling/heating  circuit  mainly in cold countries like European nations.


The sole purpose of thermo plunger is not cold -starting. Its main function is to make the passenger compartment little warmer and de-froze the windshield during extreme cold weather conditions, During early mornings at some extreme cold countries, the engine will take little time to send the required heat to this defrozer and passenger heater, and that job is fulfilled by this thermo-plunger unit

Thermo plunger is used in Nissan Juke K9k diesel version, Qashqai k9k engine, R9m engine variant, Volkswagen Tdi variant in extreme cold countries like Europe and Russia.

When diesel engine is in idle condition, ie. before moving the vehicle , the engine will produce less amounts of heat. At such cold conditions, this thermo-plunger will play a major role.

Once your vehicle started moving and more heat is produced by the engine, the engine coolant will reach a sufficient temperature to operate heater and the thermo-plunger will switch off. Thermo-plunger will be present coolant circuit between heater outlet and engine inlet circuit and it will be operated by an electric relay.