How to start a car engine when it's very cold

How to start a car engine when it's very cold
How to start a car engine when it's very cold

Winter is always a difficult season for cars, especially for the batteries which are strained. Like any other mechanical part, a battery must be serviced all year round and when the first cold weather arrives, you must know how to operate so that you can start calmly and not be late for your appointments.


Part 1 of 4: start a car engine

Start a Car in Freezing Cold Winter Weather Step 2

Step 1. Avoid pulling too much on the battery

In summer, it is true that starting problems are rare. On the other hand, as soon as the first frosts arrive, it is important to take certain actions, as we will see, to put all the chances on your side in order to start without a hitch.

  • Close the car doors (you save the electricity consumed for the indicator light on the dashboard).
  • Turn off anything that uses electricity unnecessarily: the heater, turn signals, car radio and headlights.
Start a Car in Freezing Cold Winter Weather Step 3

Step 2. Start your engine

To do this, turn the ignition key and hold it fully, but not for more than ten seconds. If the car does not start and if you keep trying to start it, you risk draining your battery for a long time.

  • Once the ignition is on, see if everything lights up on the dashboard. If so, your battery certainly has a good level of charge, but not necessarily enough to drive the starter.
  • If nothing lights up on the dashboard, if nothing happens when you turn the ignition key all the way down, you're pretty sure your battery is dead. Do not insist and take the necessary measures: either recharge the battery, buy a new one, or use the battery from another vehicle. In the latter case, you are not fixing the battery problem.
  • Turn the ignition key. The engine may not start the first time, but after a few seconds. Usually, you will feel whether the engine is ready to start or not.
  • If you hear a click when starting, you can be sure that you do not have enough current to crank the starter. No need to insist, the battery is dead, temporarily or permanently.
  • If you miss your start for the first time, wait a few minutes and try again: you never know! The battery could have been surprised and in the meantime enough current was generated to start the engine.
Start a Car in Freezing Cold Winter Weather Step 4

Step 3. If this fails, allow the battery to recharge

If your car definitely doesn’t start after about 20 seconds, don’t insist. Wait five minutes for your battery to recharge naturally. Thanks to the chemical reaction, it also takes a few degrees, which is not negligible. Likewise, this waiting allows the carburetor, often flooded, to empty of its fuel.

  • If you feel the engine is ready to start, don't push it. Wait a minute or two, then try again. At the end of this time, if your vehicle did not start, there would be a very high probability that your battery would be out of service.
  • After several unsuccessful attempts to start, you can always remove the battery and put it in the warm for a few tens of minutes. This can be effective, but also remember that the whole engine is cold and that starting is always best with parts at a minimum temperature of moderate temperature. In the event of extreme cold, your battery will return to room temperature after two hours.
Start a Car in Freezing Cold Winter Weather Step 5

Step 4. Consult the manufacturer's manual

There are always two or three pages devoted to hard starting, especially in cold weather. Also read the battery maintenance instructions. Follow the instructions carefully and carry out the recommended checks.

  • If you no longer have the service booklet (or technical review) you can most certainly order it from the manufacturer's website, otherwise you might find it at a paper fair or parts supply store. automobiles.
  • In the Internet age, it is now possible to refer to the manufacturer's site (of the car and the battery) in order to obtain interesting information. There is no shortage of amateur mechanic sites either. In a search engine, type something like "service manual [make + model + year of vehicle]" or "cold start car".
Start a Car in Freezing Cold Winter Weather Step 1

Step 5. Step on the accelerator pedal before driving off

If your car has an older carburetor fuel, pressing the throttle will put more fuel into the carburetor, making it easier to start. This only works on gasoline engines, there is no need to try with a diesel, nor with recent engines which are mostly injection.

Part 2 of 4: get started with an auxiliary battery

Start a Car in Freezing Cold Winter Weather Step 6

Step 1. If this fails, use another vehicle's battery

If you have nothing left when you start it up, your battery is probably dead or totally discharged. Fortunately, you will be able to boot from another battery. For that, you need another car, that of your spouse or a friend and a pair of differentiated cables with large alligator clips.

Start a Car in Freezing Cold Winter Weather Step 7

Step 2. Correctly position the recovery car

If the two batteries are at the front, place the two vehicles face to face, without touching each other, the goal is simply to bring the two batteries together, as the cables are not very long.

Start a Car in Freezing Cold Winter Weather Step 8

Step 3. Correctly hook the cables

Locate the “+” (red) and “-” (black) terminals of both batteries. These signs are either inscribed on the terminals or engraved on the top of the gray terminals. Look for the same signs on the alligator clips. The “+” cable will connect the two positive terminals of the batteries, while the one with the negative sign will connect the two negative terminals.

Be careful though! There is a connection order to respect. Connect the red ("+") clamp first to the positive terminal of the faulty battery, then the other end to the same terminal of the active battery. The black cable will be connected to the negative terminal of the charged battery, while the other end will be connected to the mass i.e. to a bare metal part of the broken down car, a large bolt or a lug. of fixation. Thus, you will avoid a short circuit

Start a Car in Freezing Cold Winter Weather Step 9

Step 4. Wait a few minutes

Current is transferred from the charged battery to that of the broken down vehicle. Start the car in good running order and, if necessary, idle around 2000 rpm.

Reset a Factory Car Alarm Step 3

Step 5. Try to start the disabled car

If it didn't start, check your cables, especially the black cable which should not be plugged into the failed battery. Always leave the other vehicle running and try starting again without pushing too hard.

Start a Car in Freezing Cold Winter Weather Step 10

Step 6. Disconnect the cables

Once the car has started, disconnect the cables in the reverse order of connection. Let the two cars idle for about ten minutes: the weak battery can then be recharged and the battery in good condition, complete its charge. The alternator is one part of the car's electrical system: it is used to recharge the battery while the engine is running. A simple idle is enough to make it run at full speed.

Start a Car in Freezing Cold Winter Weather Step 11

Step 7. Optionally replace the battery

In general, today's batteries last 5 to 6 years before giving out abruptly. It is difficult to anticipate this failure. There is then nothing more to do, because the balance of the internal components (acid-lead) is upset.

  • If you change your battery yourself, have the engine off, handbrake engaged and gear shifted.
  • When handling, protect your hands with gloves and your eyes with suitable goggles. This way, in the event of an incident (dropping the battery), you will not be hit by the acidic liquids and vapors that will inevitably escape from the shattered battery. The used battery should not be thrown away just anywhere. You can drop it off at a garage or at the recycling center in your town. It will then be recycled according to the standards in force.

Part 3 of 4: prevent startup problems

Pass Your Driving Test Step 6

Step 1. Warm up the engine with an engine block heater

The latter is a small device that is placed on the engine block or on certain hoses. It works on the sector. Its purpose is to heat the metal parts and to thin the oil in order to have an optimal start. Its cost is low, but its installation, for maximum results, should be entrusted to a qualified mechanic.

Start a Car in Freezing Cold Winter Weather Step 12

Step 2. Have a medium temperature battery

A cold battery is much less efficient than the same battery at a temperature of 20 ° C. In winter, you can then use a heated battery cover.

In the form of a preformed cover or a small cover, this heating element is placed around the battery and plugs into the mains. Small resistors then heat the battery: allow an hour to reach a gentle temperature

Start a Car in Freezing Cold Winter Weather Step 13

Step 3. Park your vehicle under cover

The ideal for a car is to park in cold weather in a garage. If the latter is heated, it is even better. You should then no longer experience these startup problems.

Start a Car in Freezing Cold Winter Weather Step 14

Step 4. Put a finer oil

As winter approaches, during the last oil change, consider putting a slightly less viscous oil in your engine. This is because during very cold weather the oil tends to get thicker, which causes lubrication to hurt. A special cold oil allows better circulation of the fluid and you will save fuel. See what the builder says in the booklet provided with purchase.

Start a Car in Freezing Cold Winter Weather Step 15

Step 5. Consider adding fuel antifreeze

This is especially true for diesel engines. Today, tankers sell seasonal diesel in the winter. Normally, all the stations sell it, profits oblige. But if, unfortunately, this was not the case, be aware that there are small bottles of antifreeze that you simply have to pour into the tank at a certain dosage. Be sure to read the instructions on the packaging. The problem is less common with unleaded.

This antifreeze should be poured before refueling, the reason for this is quite simple: as the fuel comes in force, it will mix better with it

Start a Car in Freezing Cold Winter Weather Step 16

Step 6. With a diesel engine, consider putting in a conditioner

It is in fact an additive that has several effects: it prevents the fuel from cooling, but it also cleans the pump and the injector lines and helps reduce pollution. Such an additive is essential in very cold regions, such as in the Jura or the Alps.

Start a Car in Freezing Cold Winter Weather Step 17

Step 7. In winter, refuel regularly

Indeed, condensation appears on the walls of the tank, and manages to slip into the hoses. When cold, this water freezes, cutting off the power supply. A car with a half-full tank starts worse than the same car with a full tank. Use the pump more regularly.

Part 4 of 4: Preparing your car for winter

Start a Car in Freezing Cold Winter Weather Step 18

Step 1. Replace your wiper blades

Also take the opportunity to change the washing liquid. Indeed, under the effect of bad weather (sun or intense cold), the rubber blades of the windshield wipers end up cracking, which means that your windshield is no longer cleaned as well. Add to that that if you drive in bad weather (rain, snow, fog) you are driving in dangerous conditions. Replace your wiper blades every six months.

Start a Car in Freezing Cold Winter Weather Step 19

Step 2. Check your tire pressure

If you are in an area with cold winters, fit snow tires. During a winter day, the temperature differences between day and night change the air pressure in the tires and driving with improperly inflated tires is dangerous. Drive quietly to the nearest gas station where you will then inflate to the pressures indicated by the manufacturer.

If you drive in areas with a lot of snow in winter, you most likely fit your car with snow tires or you have a set of chains in your trunk. On the use of these, you should know that it is subject to prefectural decision, the chains damaging the coating if there is no snow

Start a Car in Freezing Cold Winter Weather Step 20

Step 3. Do regular maintenance on your battery

Winter is a dreadful season for batteries. Because of the cold, the chemical reaction that generates the current is less active and much slower. The conductivity of cables is also affected. A little maintenance two or three times a year keeps the battery in good condition. On this occasion, you will check for the presence of residues, the level of electrolyte inside the compartments and the condition of the cables. If your battery is over five years old, expect it to fail. With viscous oil, also expect more laborious starts. This is why a fall oil change with multigrade oil (eg 10W30) is necessary.

  • Also check the battery cables, as well as the lugs that cover the battery terminals. Check if the cables are damaged or twisted and if the terminals are not surrounded by corrosion (white or green powder). To make it disappear, put on gloves, get an old toothbrush on which you will put a paste made of sodium bicarbonate with a few drops of water. Rub the areas affected by corrosion, then dry with a rag.
  • A battery contains an acidic liquid which allows the chemical reaction and it happens that on old batteries, the level drops. The top has removable caps to check the electrolyte level. If the level is too low, carefully pour in distilled water until the inner fins are covered.


  • Before you leave in the morning, clear your car of snow and ice formed overnight. Start your vehicle and while the engine is idling, take the opportunity to clear all the snow and ice deposited on the vehicle. Thoroughly clean the windows, mirrors and the inside of the fenders. Also clear your windshield wipers, check that they are working, as well as the cleaning jet.
  • To preserve your battery, you can also take it apart and put it down for the night in a warm place. Granted, the process is tedious, but if you have to spend half an hour every morning starting your car, it might be worth it.
  • Likewise, idling the engine for a few minutes allows the oil to warm up. Thus, it becomes more fluid and can therefore fully fulfill its function, even in very cold weather.

Popular by topic