Why Your Car Won't Start in Cold Weather and How to Fix It

Cold weather and freezing temperatures can cause problems with your car's battery and other components, which can make it impossible to start your car on winter mornings. Discover the reasons behind these issues and for some helpful tips to get your car up and running in the cold weather.

What are the main reasons my car won't start when it's cold?

One of the main reasons for a car not starting in cold weather is a weak or discharged battery. Batteries rely on chemical reactions to generate the necessary electrical current and these reactions slow down considerably in low temperatures. When the temperature drops outside, your car's battery cannot always deliver enough power to start the engine, making it impossible for the starter motor to turn the engine. Another reason for a cold car not starting is that engine oil can become thicker and more viscous in cold temperatures. This can make it harder for the components in the engine to move freely, and increased resistance can cause problems with the starter motor.

My car won't start in cold weather but the battery is good. What else could be causing the problem?

While a weak battery and thick oil are the most common culprits for a car not starting from cold, there are a number of other factors that can cause problems. In extremely cold conditions, any moisture present in the fuel line can freeze, which blocks the flow of fuel to the engine. Furthermore, just like the engine oil, transmission fluid can thicken in low temperatures, making it harder for the transmission to engage properly. If you have a diesel engine, glow plugs are used instead of the spark plugs seen in a petrol engine. If they are not working correctly, the engine will struggle to start.

What else can I do if my car struggles to start when cold?

Ensure your battery is in good condition by having it tested regularly and replace it if necessary. If the terminals are corroded, this could be a sign the battery is ageing. At Protyre Autocare, we offer a comprehensive servicing scheme with three levels, gold, silver and bronze. All of our servicing levels include a battery inspection where we will check the terminals and charge levels. We will also check and top up the anti freeze in your cooling system, if required. Consider wrapping any exposed fuel lines with insulation as this can help prevent freezing and ensure a consistent fuel supply. Trying to use synthetic motor oil can improve cold-weather performance, as it flows more easily at low temperatures compared to conventional oils. If you own a diesel vehicle, replace faulty glow plugs to ensure that your engine preheats and starts in the most efficient way.

If your car still won't start after trying these preventative measures, it is best to seek advice from professionals, such as our experts at Protyre Autocare. We have a network of over 180 local garages throughout the UK, where we offer servicing and free vehicle checks like our seasonal safety check. This 6-point safety check will cover wiper blades, oil levels, lights, and battery health, and we will also top up your screen wash if required. At Protyre Autocare, we are also experts in tyres and tyre safety so our free winter check will also check that your tyres are still legal and safe for winter conditions. If you need new tyres, we also stock popular and reliable brands such as Pirelli, Bridgestone and Falken. Use our 'find your garage' tool to locate your nearest Protyre garage.

Frequently Asked Questions

My car wouldn't start in the cold this morning, what can I do to fix this?

Try and park your car in a garage or covered area because keeping your vehicle out of the winter conditions can help maintain a warmer engine and battery temperature.

My car's struggling to start when it's cold. Will warming up the engine help?

Yes, if your car is struggling to start when cold, before you set off on a long journey in cold temperatures, let your engine warm up for a few minutes. This will help to thin out the oil, make it less viscous and improve the performance of your vehicle.