What is the car engine block freezing temperature?

This blog post will answer the question, ‘What is the car engine block freezing temperature?’, and cover topics like how to prevent freezing of the engine block, how to help the car start during winter, and factors contributing to a freezing engine block.

What is the car engine block freezing temperature?

The freezing temperature of the car engine block is estimated to be at -36F or -38C. This is the temperature at which the mixture of engine coolant and antifreeze undergoes solidification.

How to prevent freezing of the engine block?

These are the following ways to ensure a car engine block does not freeze.

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.

How to help the car start during winter?

These are the following methods to help a car start during the winter months:

  • 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.

Factors contributing to a freezing engine block

These are the following factors that are responsible for freezing the engine block.

The main reason behind a car having the engine block frozen is excessively cold temperatures. This mainly occurs during the winter months. The other factors to be considered are as follows.

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.

Research shows the various 12V car heaters available in the market.


This blog post addressed the question, ‘What is the car engine block freezing temperature?’.

We understood the various ways to prevent the freezing of the car engine block, and also came across the methods to start a car during cold weather. Furthermore, the factors contributing to a frozen car engine 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): What is the car engine block freezing temperature?

What happens if your engine block freezes?

In case of the engine block freezes up, the car engine can suffer from overheating and soon explode due to several blocked passages within.

How do you thaw out a frozen engine block?

Thawing out a frozen engine block is recommended to be carried out in a closed space like a garage or a shelter. A source of heat like an electric fan can be used to melt the snow faster and speed up the thawing process.

Does revving your car warm it up faster?

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