We’ve all been there — it’s freezing outside, and just when you’re ready to head out, your car refuses to start. Winters have chilled ways of messing with your car’s systems, leaving you out in the cold.
But have you ever wondered why your car won’t start in the cold?
And more importantly, what can you do to get it up and running again?
We’ll explore some common reasons cars struggle during winters and offer practical solutions for restarting your cold engine. We’ll also share handy tips on winter-proofing your vehicle so you’re not caught off guard when the temperature drops.
Let’s get started!
This Article Contains:
- 7 Key Reasons Your Car Won’t Start in the Cold (+Fixes)
- How to Start a Cold Car in an Emergency: 3 Effective Ways
- How to Care for Your Car During Winter Months
7 Key Reasons Your Car Won’t Start in the Cold (+Fixes)
When your car refuses to start in the cold, it could be due to a dead battery, faulty spark plugs, or if you’re using the wrong oil. Whatever the case, it’s best to have a professional look into the problem.
But to give you an idea, here are some common problems behind a no-start in cold temperatures and how to fix them:
1. Cold Car Batteries
Car batteries rely on a chemical process to produce and store electricity. However, cold weather, especially freezing temperatures, can increase the battery’s electrical resistance, affecting its ability to hold a charge.
If you hear a whining noise during ignition but the starter motor doesn’t engage, it’s likely due to a battery issue.
How to fix:
You can jump-start your car to temporarily boost your weak battery. But, if your battery loses its charge frequently, it’s time to replace it.
NOTE: Since EVs are powered exclusively by a battery, cold weather can reduce battery efficiency, decreasing their all-electric range.
2. Faulty Alternator
Got a new battery that keeps going flat?
Chances are your car is having starting problems due to a bad alternator. A failing alternator won’t be able to recharge your car battery while your car is running.
How to fix:
Get a professional mechanic to test your alternator and swap it out with a new one if needed.
3. Faulty Starter Motor
If your car electronics work, but you hear a click when turning on the ignition and the engine doesn’t crank, it’s due to a bad starter motor. Sometimes, the starting problems could be due to a faulty starter solenoid.
How to fix:
You can temporarily jump-start your car with a bad starter, but it’s best to drive straight to an auto repair shop for a starter motor or its solenoid replacement.
4. Fuel System Problem
Your vehicle’s fuel system relies on a fuel injector, a fuel pump, a filter, a pump relay, and several hoses to transfer fuel from the gas tank to the combustion chamber for ignition.
Over time, one or more of these components can leak moisture into the fuel system. The lower temperature during winter months can cause this moisture to freeze, preventing fuel flow and the engine from cranking.
How to fix:
You’ll need a mechanic to flush the fuel system. They’ll drain the fuel tank and thaw any frozen fuel line. They’ll also replace the fuel filter and other damaged components like the fuel pump, ensuring no remaining contaminants block fuel flow.
NOTE: Petrol’s freezing point is below -50°C, so it remains liquid unless exposed to extremely low temperatures.
5. Using the Wrong Engine Oil
If your vehicle uses a thick oil like 10W-30, it can thicken even more in low temperatures, making a cold start challenging for the engine.
How to fix:
You should use the correct oil viscosity as recommended by the manufacturer, especially one rated for winter conditions (like 5W-30 or 0W-20). This ensures better cold-start performance and proper engine lubrication during low-temperature conditions.
NOTE: Unlike coolant, engine oil doesn’t freeze but becomes highly viscous, making it crucial to use oil with a lower “W” rating (such as 5W-20) for optimal winter performance. Switching to synthetic oil can also be beneficial, as it flows better in cold conditions and offers superior protection against engine wear.
6. Your Car Is Fitted with a Carburetor
During a cold morning, moisture in the air can freeze inside the carburetor, particularly around the throttle plate or in its nozzle. This ice buildup restricts the airflow and disrupts the fuel mixture ratio, causing the cold engine to either not start or run poorly.
How to fix:
- Place one foot on the clutch.
- Then, push the accelerator pedal with the other foot as you turn on the ignition switch. This will pre-inject some additional fuel in the engine block to help start your car.
7. Aging Spark Plug
Old or worn spark plugs can’t generate a strong spark, which is crucial for the air-fuel mix ignition. In cold weather, the fuel mixture is also harder to ignite because it’s denser and doesn’t vaporize as easily, so a weak spark can prevent the ignition system from working efficiently.
How to fix:
Have your spark plug set and other ignition system components checked and replaced by a mechanic. Ideally, you should get your plug inspected or replaced every 30,000 to 90,000 miles.
Now you know what could be causing the starting problem in your car.
Let’s see what you can do immediately to get back on the road.
How to Start a Cold Car in an Emergency: 3 Effective Ways
Here are some options you could try to crank up your engine when your car won’t start on a cold morning:
1. Turn Everything Off
If you’re facing a starting problem during extreme cold weather, turn off the headlights, car heater, and other electronic accessories before attempting to crank the engine. This helps focus the battery’s power on starting the car.
Once the engine starts running, allow it to idle for a few minutes before turning on the heater or other electronics.
2. Jump-Start Your Car
As mentioned, if your car battery dies, you can try to jump-start it using another car with a charged battery.
Here’s how:
- First, connect the red jumper cable to the positive terminal of your dead or weak battery and then to the donor battery’s positive terminal.
- Next, connect the black cable to the donor battery’s negative terminal and the other end to an unpainted metal surface on your car.
- Start the donor vehicle and let it run for a few minutes.
- Then, crank your engine; if it doesn’t start, wait a minute and try again.
- Remove the cables in reverse order: black from your car, black from the donor, red from the donor, and red from your car.
- Keep your running for 15-30 minutes to recharge the battery via the alternator.
3. Call Roadside Assistance or a Mobile Mechanic
If none of the above works, call roadside assistance for a tow truck or book an appointment with a mobile mechanic.
Next, let’s explore some tips and tricks to steer clear of car trouble all winter long — because a little care goes a long way in battling cold conditions!
How to Care for Your Car During Winter Months
You can do the following to prep your car for extreme cold:
- Charge your battery weekly to keep it in good condition, especially if it’s over three years old and used for short trips.
- Keep the fuel tank half full to prevent moisture accumulation in the fuel system and avoid a starting issue.
- Consider investing in an engine block heater to keep the engine warm overnight for an easier cold start.
- Use covered parking to protect your car from freezing temperatures and help fluids flow better.
- Start the car and wait 30 seconds for the engine to warm up. Then, drive gently for the first few minutes.
- Choose oil with a lower “W” number for better flow in cold temperature conditions.
Ensure Smooth Starts in Cold Weather with AutoNation Mobile Service
When your car has a starting issue in freezing temperatures, a couple of factors are at play. While you can take certain troubleshooting steps, it’s always best to prevent this situation from occurring.
And if you still face issues cranking your engine in extreme cold weather, AutoNation Mobile Service can help.
We’re a mobile auto repair solution available seven days a week. All our repairs come with a 12-month, 12,000-mile warranty.
Contact us today, and our mobile mechanics will get your cold vehicle up and running right from your driveway!