What Is a Car Diesel Heater?


– Diesel heater: characteristics

– Current use of a diesel heater

About 40 years ago, an icy spell handicapped many users of diesel-powered vehicles. Thousands of cars were immobilized, and cars were left stranded all winter due to freezing diesel fuel. In the stores, the diesel heaters were therefore taken by storm. We tell you about it in this post!

Diesel heater: characteristics

The particularity of diesel (a waxed product) is to freeze in the cold: if the lessons have been learned and oil companies now distribute protected diesel in the cold season, the diesel heater is an essential element for the engine supply, as a first fitment or adaptable, whose purpose is to bring the diesel to a moderate temperature to avoid freezing and optimize the engine combustion.

The heating is carried out by electrical resistance in direct or indirect contact with the fuel or the engine cooling system.

The diesel heater exists in several versions: 

1. Models adaptable by electrical resistance, 

2. Heating by the coolant, 

3. Original assembly,

1. Models adaptable by electric resistance

Made up of a heating resistor, they are inserted in the diesel circuit, often near the fuel filter, and a probe can regulate the temperature. These devices have become very rare in cars, as modern engines are equipped with them as standard.

2. Heating by the coolant

Originally fitted and tending to disappear, it consists of an aluminum alloy block with two contiguous sealed circuits: the cooling system circuit indirectly heats the diesel circuit through the housing walls.

3. The original assembly

Diesel engines with direct injection and high pressure “common rail” are equipped with such equipment as standard.

In addition, there is often a parallel fuel cooler in the return line, which lowers the temperature of the overheated diesel fuel (50 to 100°C) due to the injection pressure to avoid condensation and water in the tank.

Located in the fuel filter housing, they are controlled by the engine’s electronic management system to maintain a stable temperature (presence of a fuel temperature sensor or thermostatic element); the main goal is to optimize combustion (for a fuel temperature between 15 and 25°C).

Current use of a fuel heater

A new episode of (very) cold weather cannot be excluded, and the contribution of a fuel heater would then become decisive. 

What you should know:

– its electrical resistance consumes from 150 to 300 W, an amount fairly sustainable by the battery.

– it is placed on the pipe or the filter support; it can take the form of a belt encompassing the diesel filter, it does not take much space under the hood.

– it does not present any particular difficulty, except some knowledge of electricity to connect a relay feeding the heating resistor.

– the average financial cost is $80. For the more do-it-yourselfers, it is possible to make one by hand, the cost of supplies being $30.

– it is possible to buy them on specialized diesel websites.

Hope this post has helped you understand the importance of diesel heater for cars. If you often face cold fuel problems and your vehicle is not equipped with a diesel heater, talk to your mechanic about the possibilities of getting one mounted on your car, and remember to share your experience below.

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– 4 Essential Tips to Clean a Car Injector

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– My Car Is Overheating! What Could Be Wrong?


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