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Car Won’t Start in Cold: Here’s What to Do
February 4, 2025

Car Won’t Start in Cold: Here’s What to Do

You’re not the only one who struggles with oversleeping in winter. Your car also could have trouble getting an early start too sometimes. Nearly half of all car troubles reported in winter are related to starting. While we relate to the car, we still have to go on our way to make ends meet. If your car won’t start in cold weather, here are some of the potential reasons and how to overcome them.

Why Won’t Your Car Start in the Cold?

For your car to start, you need all components to work together, from the starter motor coming to life and receiving an electric current from the battery to the activation of the pistons. If anything fails to do its job, the car won’t start. Here are some of the reasons why your vehicle may not start.

Battery Issues

Extreme cold weather significantly affects the performance of the car battery. As the temperatures drop, the chemical reactions inside the battery slow down, leaving the car with less available power to start. The car battery’s capacity decreases by 20-35% at 32°F (0°C). It loses more than 50% of its capacity at 32°F (0°C).

For older batteries, over 3-5 years, it gets worse. They may not hold the charge effectively in cold weather, making it harder to start the car. Starting a car in cold weather requires more energy, so it strains an already weak battery.

Diagnosing the problem is easy. Signs of battery issues are dim headlights, a clicking sound when turning the key, or no response when turning the ignition.

Read Our Helpful Guide:

Thickened Engine Oil

In cold weather, the engine oil becomes viscous or thick, making it hard to turn over the engine. It’s important to avoid using the wrong oil as it makes the problem worse. Experts recommend switching to oil with low viscosity, especially in winter. For example, grade oils 5W-30 or 0W-20 flow better in cold weather. Refer to your vehicle’s owner’s manual to learn which oils are best for your vehicle.

Frozen Fuel Lines

Another reason behind your car not starting might be an issue with the fuel system. When the temperatures drop below freezing, moisture in the fuel lines can freeze, blocking the fuel from flowing to the engine. This especially happens to cars with a near-empty fuel tank because the condensation builds up easily. So, it’s important to keep your fuel tank at least half-full in winter. We also suggest using fuel-line antifreeze or fuel stabilizer to prevent freezing.

One of the fuel system problems that older vehicles might face is carburetor icing. Cold temperatures may cause moisture to reach a freezing point, restricting airflow and preventing the engine from starting.

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Starter Motor Problems

Your car won’t start if the starter motor is weak. The starter motor is responsible for cranking up the engine. Increased resistance from thick engine oil may strain the starter motor in winter weather. The strained motor may fail to generate enough power to start the car.

If you hear a clicking noise when you attempt to start the car and the engine won’t crank at all, then the problem might be the starter motor. Before the winter season starts, have a professional mechanic check the car’s starter motor.

Spark Plug or Ignition Issues

Your car may “lose its spark” if the spark plugs are old or worn out or if the ignition coils are damaged. In both cases, there won’t be power to ignite the fuel-air system and start the engine. Remember that starting a car in cold weather requires more power than usual. This is usually a maintenance issue. It’s important to follow the manufacturer’s recommended maintenance schedule to make sure everything works optimally.

Frozen Components

In frigid weather, some components, like the coolant or the fuel pump can freeze, preventing the engine from starting. For example, the coolant mixture may reach a freezing point if it lacks sufficient antifreeze. The result is an engine block cracking or a seized engine. Using the right mixture of antifreeze – 1:1 antifreeze to water- might prevent that. Using engine block heaters can also help.

How Can Engine Block Heaters Help When My Car is Too Cold to Start?

If you plug in the block heater a few hours before starting the car, you ensure the engine is at a suitable starting temperature. A block heater is one of the many winter car accessories you can use in winter weather to ensure your car starts in extremely cold weather.

 

How to Start Your Car in the Cold

Trying to start your car in winter only to find that it won’t cooperate is frustrating. Here are some steps to take to help you get on the road.

1. Check the Battery

First, turn off all the accessories so the battery doesn’t drain further. Make sure the heater, headlights, radio, and other electrical components are turned off. Then, try starting the car by turning the key or pressing the start button for no more than 10 seconds. Afterward, you should wait 15-30 seconds before trying again to avoid overworking the starter motor.

2. Warm Up the Battery

If the car doesn’t start after the first step, it might mean the battery is weak or frozen. In that case, there are still some ways for you to solve the problem.

For a car with a manual transmission, you can start by pumping the brake pedal or pressing the clutch to help the car generate a small current. If your car has an automatic transmission, skip this step and proceed with the next.

If the battery is cold or frozen, warming it might improve performance, you could turn on the interior lights briefly for that. If all fails, your car may need a jump start.

Your Jump Start Options:

  • Use a portable jump starter.
  • Jumpstart your car with another vehicle’s battery.
  • Call the CDRA professional battery boost service

Also serving other Alberta areas:

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3. Check the Fuel

Frozen fuel lines can stop your car from starting. As a general rule, keep your gas tank at least half-full at all times in winter. If the tank is almost empty, condensation will build up causing moisture and freezing. For the older models, we have a trick up our sleeve. You could turn the key to the “ON” position without starting it a few times to let the fuel pump pressurize the system.

4. Warm the Engine

If the problem is a cold engine, there are a few ways to warm up the engine. Plug your block heater if you have one for 2-3 hours before starting the car. For older cars with carburetor engines, you could press the gas pedal once or twice before starting the car to prime the engine.

 

5. De-Ice Frozen Parts

If you still can’t start the car, it may be that frozen components are preventing it, you can try de-icing them:

  • If the lock or seal is frozen, preventing you from accessing or starting the car, you can use a lock de-icer by squeezing it into the lock and waiting a few minutes for it to do its magic.
  • Check the intake system to make sure ice isn’t blocked by ice or snow.
  • If the fuel lines are frozen or gelled, you can try tapping them gently.

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6. Call Roadside Assistance

If all else fails, you can always call 1- 866-519-4001 one of Canada’s best emergency roadside assistance services. They can diagnose the problem and help you get moving in a short time. Many services, like Canada Direct Roadside Assistance, offer many different services, including battery boost, car towing service, lock replacement, winching, flat tire changing, and fuel delivery near you, So, whatever problem you have, they will find a solution for you.

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How to Care For Your Car in Winter and Avoid a Cold Start

Winter is a demanding season for vehicles; you need to give your car extra care to keep it up and running all season long. Here’s our top advice on how to care for your vehicle in winter to avoid the mishap of a broken-down car.

1. Prep Your Car for Winter

Prepping your car for potentially unpleasant scenarios saves you time and effort. For one, at the beginning of winter, you should check all components and make sure everything is functioning properly. Most importantly, check the tire tread, brakes, and battery as they are the most likely to cause trouble if not in good shape. For tires, consider adding winter tires for better traction and handling. You could also wrap your battery in a battery blanket to avoid it losing much of its capacity in winter.

2. Warm Up the Engine

While car idling for 5 minutes is unnecessary for newer cars, it helps to let your car warm up before hitting the road at full speed. Here’s how you should do it:

  1. Start the car
  2. Keep it running without driving for 30 seconds.
  3. Drive slowly for the first few minutes.
  4. Your car should be warmed by now.

3. Keep the Car Well-Covered

While it’s tempting to park your car in the nearest spot on the driveway, it exposes all its outer and inner components to extreme cold. This leads to frozen fluids that may stop the car from running. Consider parking your car in a heated garage or carport overnight to keep it warm, shielding it from cold weather, rain, or snow.

 

Car Won’t Start: Troubleshooting Questions

Why my car won’t start when it’s cold but it starts in warm weather?

If your car is too cold to start in winter, the battery might be weak. Car batteries, especially old ones lose much of their capacity in cold weather. If not, it could be the engine oil getting thicker, making it hard to turn over the engine. Also, a frozen fuel line might be the cause if the tank is almost empty. Start with checking the battery, then the engine oil and the fuel system.

What does it mean if my car won’t start in the cold but the battery is good?

If your car battery is new or in good condition, then the problem might be in the starter motor. The starter motor is the engine motor that uses an electric current to turn over the engine and start the car. Check the starter motor if the battery isn’t the problem.

Read Our Helpful Guide:

Why is my car turning over but not starting in the cold weather?

The problem might be frozen fluids as a result of moisture seeping in, especially if you have worn fuel or brake lines. The frozen components lead to blockages that prevent the car from starting. Moreover, the cold weather increases the resistance from electric parts, making it harder for the spark plugs and battery to work properly.

Why my electric car won’t start in the cold?

In winter, the cold slows down the battery’s functionality making it harder to produce electricity. That’s why your EV might perform differently in winter. The battery can’t receive or take charge as easily as in milder months. The solution is to precondition the car by heating it shortly before you start it while it’s stationary. Also, try to be wise about battery consumption as EV batteries already struggle in winter.

Why won’t my diesel car start in the cold?

If your car runs on diesel fuel, you might face some trouble with it starting in winter because diesel fuel doesn’t vaporize easily in the cold, so it needs more heat to start compared to gasoline. So your diesel car might fail to start in winter. Here’s what to do if your diesel car won’t start in winter:

  1. Warm the car before operating.
  2. Consider using heating options, like a block heater, a diesel-fired coolant heater, or glow plugs.
  3. If the fuel is frozen or gelled, change the fuel filter and warm up the car.
  4. Store the diesel engine in a warm area.
  5. Make sure the fuel tank is full.

Why won’t my car turn over when it has enough power?

Again, the problem might be a low or weak battery. If it’s not the battery, it could be a bad starter, alternator, or another electrical issue.

Read More: Signs of a Bad Alternator vs Bad Battery: The Ultimate Guide

Why won’t my car battery start in cold weather?

Use auto parts, like a battery tester or multimeter, to check if your battery is charged or not. Cold temperatures can reduce the battery’s power and make it hard for the engine to start. If that’s the case, give the car a jump start or replace the dead battery.

Frequently Asked Questions

At what temperature should you plug in your car?

It’s best to plug in your car before using it at -15C. This ensures the longevity of your car, as the engine components get enough oil and aren’t worn out. Plugging your car warms up the engine block heater, warming the coolant, engine block and oil in return.

How often should you start your car in extreme cold?

If you’re not driving your car for a long time in winter, then we recommend starting it at least once a week. Start the engine and leave it running for 10-15 minutes to allow the engine to reach the best operating temperature and circulate the oil. Doing this regularly is crucial to maintaining engine health.

How do I keep my car battery warm in winter?

To keep your car warm in winter, heat the car before starting it by turning on the headlights. We also advise parking in a heater garage or investing in a car cover to shield the car from very low temperatures. You could also use a battery heater and plug in the engine warmer to avoid power loss.

How do I warm up a frozen car engine?

First, move the car to a warmer place. Then, catalyze the thawing process by using a fan heater where the heat helps melt the frozen fluids faster. Do not drive the car unless the cooling system is completely thawed.

Will a dead car battery recharge in the cold?

A dead car battery doesn’t recharge on its own. If the battery is just drained and not damaged, you can recharge with a jump starter, another vehicle, or any suitable power source. Note that the cold weather doesn’t prevent the battery from charging, but it slows down the process.

Why is my car cranking but not starting?

If your car is cranking but not starting, it means the car’s starter is working, but there’s a problem with the engine itself. If fuel might not be getting to the engine, check the fuel injectors to make sure they’re not clogged.

What temperature is too cold for a car to start?

At -15C, it becomes difficult for your car to start. Starting the car in chilly weather is hard on the engine, as the oil starts to thicken and stops flowing normally. The friction resulting from that labour makes engine parts wear fast.

Is it okay to start a car with the block heater plugged in?

Yes, starting the car with the block heater plugged in is okay. It doesn’t cause any harm.

How do you get a frozen car door lock open?

If your door lock is frozen, the first thing you could try is to pour warm- not hot- water into the frozen area. If the ice doesn’t melt, try using a de-icer spray.

Does motor oil freeze in cars?

While motor oil doesn’t freeze, it could get extremely thick making it difficult for the engine to run properly. Try using an oil with low viscosity during winter to avoid having trouble starting the car.

Why is my engine clicking but not starting in the cold?

If the engine is clicking in a rapid noise but the car isn’t starting that means that the starter motor isn’t getting enough electrical power to engage. In other words, the solenoid is trying to make a connection but is unable.

Roadside Assistance Services in Your Area

If your car won’t start in freezing temperatures or you’re stranded due to winter car troubles, our roadside assistance services are available 24/7 to help. No matter where you are, we provide reliable support to get you back on the road quickly and safely. Our service areas include: