How to keep your car engine from freezing?

This blog post will answer the question, ‘How to keep your car engine from freezing’ and cover topics like reasons behind car not starting in winter, how to start vehicle in cold weather, and how to keep the engine warm at night.

How to keep your car engine from freezing?

The following steps can be followed to prevent the car from freezing in the cold winter months:

  • Checking if the battery is in working condition and possesses sufficient cold-cranking amps
  • Covering the vehicle from the seasons by parking it inside a garage or under a tree
  • In colder regions, a battery heater is a good investment for keeping the car warm
  • Refer to the guidance manual for the vehicle to ensure the correct motor oil is being used for it
  • Using an additive inside the fuel tank such as dry gas will prevent water from seeping inside the tank

Reasons behind car not starting in winter

The following are the various reasons behind a car facing difficulties in starting 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 start the vehicle in cold weather?

These are the following tips that must be followed to ensure the car can start properly during cold weather:

  • 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.

How to keep the engine warm at night?

These are the following methods to ensure a car engine stays warm at night, to start normally the next morning.

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.

Using an electric blanket

In a similar manner, the electric blanket can also plug into a wall socket and can be placed as a cover over the engine to keep it warm overnight. The hood should be closed to prevent the generated heat from escaping.

Research explains why cold starting a car in winter is unusually loud.

Other articles about Mercedes Benz you may be interested in

Which are the ugly Mercedes Benz cars?

Is the Mercedes Benz C Class a good car?

Should you buy the 2022 E 63 AMG?


This blog post addressed the question,’ How to keep your car engine from freezing ’.

We understood the various reasons behind a car not starting in winter and came across some tips on how to start a car in cold weather. Furthermore, different ways to keep a car 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): How to keep your car engine from freezing?

How cold does it have to be for an engine to freeze?

Engine coolant solidifies at -32F. This is when the engine can be difficult to start and often is subjected to stalling.

Can I use just water as coolant?

Water alone fails to take on the role of an antifreeze mixture as it does not have a fixed range for the boiling and freezing point. Another important point is that it is not a good absorber of heat.

How much antifreeze does it take to keep water from freezing?

A 50:50 ratio of water to antifreeze is suitable for almost every climate. If the temperature drops below 0 degrees for a longer period of time, a ratio of 40:60 water to antifreeze helps to prevent the coolant from freezing.