[Car Tips] Reasons and Solutions for Vehicles Starting Slowly in the Morning in Winter
1️⃣ Why does the engine start slowly in the morning in winter?
Although Hong Kong doesn't experience snow like other countries, winter temperatures (especially from December to February) in the New Territories can drop to 8°C or below , which can have an impact on a car's mechanical and electrical systems. Common causes include:
1.1 Battery performance degradation
- Batteries store and discharge electricity through chemical reactions. When the temperature is low, the chemical reaction rate slows down, causing the output voltage and current to drop.
- Starting a cold car requires a larger current to drive the starter motor, but if the battery is in poor condition, a "dragging" starting sound will occur.
- Especially for batteries that have been in service for more than 3 years , the degradation will be more obvious at low temperatures.
1.2 Oil viscosity increases
- Motor oil becomes more viscous at low temperatures and does not flow as easily through the engine.
- When starting, the engine friction resistance increases, the speed starts slowly, and the starting time is also delayed.
- If the wrong brand of engine oil is used (viscosity is too high), the impact will be greater.
1.3 Fuel atomization effect deteriorates
- In cold weather, fuel volatility decreases and fuel and air are not mixed completely.
- Gasoline requires a higher atomization efficiency to ignite. When the weather is cold, the temperature of the combustion chamber is low and the ignition efficiency decreases, resulting in difficulty in initial ignition.
1.4 Starter motor aging
- Long-term use will cause the starter motor carbon brushes to wear and increase rotor resistance.
- When the battery voltage is low in winter, its rotational power will be further insufficient.
1.5 Spark plug carbon deposit/aging
- The spark plug is in poor condition and the ignition energy is insufficient. Combined with low temperature conditions, ignition failure is likely to occur or multiple attempts may be required.
💡Hong Kong editor's observation <br>Although Hong Kong's winter is not extremely cold, the low temperature and high humidity in the New Territories/Lantau Island in the early morning, combined with the combined effects of condensation and low temperatures, are enough to slow down the engine that usually starts immediately by a few seconds. This is especially noticeable for drivers who park in open spaces.
2️⃣ How to deal with slow startup (immediate processing)
2.1 Warm up the battery before starting
- Insert the key (or press the ignition key) to the ON position, do not crank it immediately.
- Wait until all instrument lights are on and then off (ECU self-test is completed).
- You can first lightly press the lights, radio and other electrical appliances for a few seconds to allow the battery to "warm up" a little, and then try to start it.
2.2 Correct startup operation
- When starting, turn the key or press the start button in one go to avoid letting go halfway.
- If it fails the first time, wait 5-10 seconds and try again to avoid overheating and excessive consumption of the battery due to continuous idling.
2.3 Reduce load
- Turn off the air conditioner, heater, fan, audio, and headlights before starting to reduce the immediate burden on the battery and increase the available current for the starter motor.
2.4 Use external power supply when necessary
- You can use a jump starter (mobile emergency power supply) or find another car to jump start your car, which is especially useful when there is no rescue service in the suburbs.
3️⃣ Prevention and long-term countermeasures (applicable to Hong Kong)
3.1 Check battery health regularly
- In Hong Kong, most urban drivers travel short distances, which means batteries don’t have enough time to charge and their lifespan is easily shortened.
- Every six months, go to the garage and use a special tester to measure the "cold cranking current (CCA)" and voltage.
- You can consider replacing the battery after the third year to avoid sudden "death" in the winter.
3.2 Use engine oil with appropriate viscosity
- Check the owner's manual for recommended winter viscosities, such as 5W-30, 0W-20, etc., for good low-temperature fluidity and low cold-start resistance.
- Although Hong Kong's winter temperatures don't reach below zero in the north, 50,000 degrees Celsius is usually enough to cover the entire year.
3.3 Maintaining spark plug condition
- Check the spark plug condition every 20,000-40,000 kilometers. Carbon deposits or excessive gaps will affect low-temperature ignition efficiency.
- Use original spark plugs or those of equivalent grade.
3.4 Parking is strategic
- Avoid long-term outdoor parking (especially in mountainous areas).
- If possible, park in a shaded or indoor parking space to reduce the net cooling effect.
3.5 Scheduled long-distance travel
- Long distance driving helps to fully charge the battery and reduces the chances of the battery being undercharged due to long periods of short driving.
3.6 Check the fuel system
- Winter is dry and rainy, so carbon deposits in the oil circuit may be more obvious than usual, affecting atomization efficiency.
- Clean the fuel injectors regularly with fuel additives to maintain normal starting fuel supply.
4️⃣ Editor’s Heartwarming Summary
Slow starting in the morning in winter is not necessarily caused by a broken car. It is more often the combined effect of low temperatures causing the battery, oil, and fuel to atomize and the ignition efficiency to decrease .
Although Hong Kong is not freezing, 8°C in the New Territories in the morning is enough to make cars with old batteries and thick engine oil feel "drowsy and listless".
Take precautions before they happen : Maintaining your battery, changing your engine oil, and keeping your spark plugs healthy are the three essential winter safety tips for Hong Kong drivers!
