Why are electric blankets used for a car engine?

This blog post will answer the question, ‘ Why are electric blankets used for a car engine?’, and cover topics like conventional ways to warm up a car engine, conventional ways to warm up the car in winter, reasons why a car engine fails to warm up, and how to keep the car engine warm overnight.

Why are electric blankets used for a car engine?

An electric blanket is used to warm up the car engine, mostly during the winter months. The heating blanket has the ability to connect to a wall socket and warm up the car engine.

To obtain the best results by using an electric blanket, it must be placed over the car engine and left overnight. An important point to be noted is that the hood of the car must be closed to prevent the heat from the blanket to escape the car.

Using electric blankets for heating up the car engine can help in warming up the engine fluids, also keeping the crucial engine hoses and pipes unharmed. It also helps in preventing the car engine components and other machinery from breaking.

Conventional ways to warm up a car engine

These are the conventional methods that are followed while attempting to warm up a car engine:

  • First, without turning the engine on, switch on the ignition. This will allow the fuel pump to prime the engine to produce more heat energy.
  • After 5-10 seconds, start the car engine.
  • The heater should not be turned on immediately as it will have cold air. 
  • The vehicle should be idled for about half a minute. Doing so allows the core of the heater to pump warmer air fast.
  • After about half a minute passes, the heater can be turned on, warm air should enter the cabin by now.
  • Before starting the drive, crank the engine a few times to let the oil flow through all the critical parts so that they receive ample lubrication before driving.
  • The engine can also be pre-warmed by means of an engine block heater, these connect easily to a socket and to the car battery.

Conventional ways to warm up the car in winter

The following are the conventional ways to warm up a car during winter:

  • Turning off all electrically operated components like the heater, defroster, windshield, headlights, etc.
  • Turn the ignition and hold it to allow the engine to crank for no more than 10 seconds to warm up the engine.
  • The above step is to be repeated and if it fails, it is advisable to warm up the battery separately before trying again.
  • If none of the above steps work, another fix includes jumping the battery.

Reasons why a car engine fails to warm up

The main reason behind a car failing to warm up is excessively cold temperatures. This mainly occurs during the winter months. The other factors to be considered are as follows.

The following are the various reasons behind a car facing difficulties in warming up during the cold winter months.

A dead battery

It is a known fact that a good battery loses half of its power at 0 F. During the cold winter months, the motor oils and other fluids thicken over time, which pushes the battery to deploy more power to start the car. 

This can be fixed by:

  • Using another vehicle with jumper cables or a jumper motor to boost the battery
  • Servicing the terminals of the battery by removing the corrosion with a wire brush
  • Cleaning the battery using a plastic brush and a solution
  • To send all the battery power to the engine, other unnecessary electric devices need to be turned off

Motor oil getting thick

In the colder months, the motor oil along with other fluids gets thicker with time and faces a hindrance while trying to migrate towards the engine.

There is also the possibility of the oil getting contaminated and facing a sludge buildup. It is, therefore, advisable to turn towards using synthetic motor oil that has winter-resisting properties and a correct viscosity to tackle the cold.

Oils that are thinner, flow better at lower temperatures. If the oil viscosity codes have a ‘W’ in them, they are suitable for usage in winter.

Fuel system freezing

Gasoline vaporizes at a slower rate during winter. Condensation of water occurs in the gas tank as the temperatures drop. Water being heavier in weight than gasoline, tends to accumulate at the bottom of the tank all the way up to the fuel lines.

As the temperatures drop below freezing point, the water freezes and blocks the fuel lines and can also jam the fuel pump. It is advisable to warm the fuel lines with a warm towel wrapped around them and a collecting medium beneath for the hot water.

Faulty engine sensors

A richer air/fuel mixture is required for combustion in colder months. In this case, particularly a malfunctioning coolant temperature sensor and an air intake temperature sensor are the ones to look out for. This is due to the fact that the malfunctioning produces a lean air/fuel mixture.

To fix this, consult an automotive technician or a professional mechanic to refer to the troubleshooting codes for a quick and permanent fix.

Defective alternator or starter motor

A defective alternator drains the battery especially if a high beam or other electrically demanding accessories are being used in the car. In winter, the brushes of the starter motor are worn out, thus they fail to run the engine with such low power input.

The best fix, in this case, is to replace the alternator and the starter motor along with the timing belt.

How to keep the car engine warm overnight?

These are the following methods to ensure a car engine stays warm at night.

Parking in a heated garage

A heated garage prevents the battery from getting too cold and also helps in preventing the thickening of the motor oil and other fluids. The optimum temperature to be maintained is somewhere between 55-72F.

Connect car battery to a heater

A block heater comes in handy in such situations as it can easily plug into a wall socket while staying connected to the battery. It prevents the battery from getting too cold which could otherwise hamper the chemical reactions necessary for the battery to start the car.

Using an engine preheater

Engine preheaters plug into the wall and are fed into the engine coolant via the radiator hose pipe. With the heating of the coolant, the warmth spreads to other engine components.

Using a light under the car hood

Deploying a 150W light bulb over the intake manifold and keeping it running overnight helps to keep the engine warm overnight to facilitate faster starting the next morning.

Research shows the various 12V car heaters available in the market that can be used to warm up the car engine.


This blog post addressed the question, ‘Why are electric blankets used for a car engine?’. We understood the conventional ways to warm up a car engine in different seasonal conditions, and also came across the reasons behind a car engine failing to warm up. Furthermore, the different ways to keep a car engine warm overnight have also been discussed. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): Why are electric blankets used for a car engine?

What helps the engine to warm up quickly?

Firstly, we should turn down the temperature and switch off the fan. After driving for a while, we turn it back up again and switch the fan back on.

Do you need to warm up a car engine?

Warming up a car engine instead of operating it while cold permits the even distribution of oil to lubricate the critical engine components. If not done, the pistons can be damaged greatly and can suffer extensive wear and tear.

Does revving your car warm it up faster?

Yes, revving the car engine can make it warm up faster.