What Causes Slow Engine Start in Cars?
4 Answers
Slow engine start in cars can be attributed to the following reasons: Increased oil viscosity: In cold winter weather, low temperatures and dry conditions cause the engine oil to thicken, slowing down its flow rate and increasing resistance in the car's engine, leading to difficulty in starting. Engine malfunction: Internal faults in the car's engine, often due to improper use, can increase engine wear, resulting in insufficient cylinder pressure and making it hard to start the car. Frozen exhaust pipe: Low winter temperatures can cause the car's exhaust pipe to freeze, making engine ignition difficult.
I've been driving an older German car for over a decade and have encountered slow ignition issues several times. The main culprit is usually the battery – after three or four years of use, its power significantly diminishes, especially noticeable during winter. Wiring aging can also cause unstable power supply, as those exposed cables in the engine compartment become brittle over time. Last time when my car had slow starts, the inspection revealed that the carbon brushes in the starter motor were worn down to half their size – replacing them immediately solved the problem. Spark plug carbon buildup similarly affects ignition, particularly for vehicles mainly used for short city trips. My recommendation is to first test the battery voltage; if it's below 12 volts, replacement should be considered.
This situation requires a comprehensive check of several key points. The first thing to look at is the battery condition. Older batteries can't hold a charge well, leading to insufficient power supply during cold starts, which causes delays. Starter motor issues are also common, such as burnt contacts in the magnetic switch or bearing wear, both of which increase resistance. Insufficient fuel pump pressure causing delayed fuel supply is another factor, especially noticeable in areas with poor fuel quality. The condition of the ignition system is also important; excessive spark plug carbon buildup or aging ignition coils can affect ignition efficiency. Finally, don't overlook the impact of temperature; in winter, poor oil fluidity increases the starting burden.
Last winter, my newly purchased SUV had slow starts, which scared me into thinking there was an issue with the new car. Later, a mechanic taught me that the frequent restarts of the auto start-stop function significantly drain the battery's lifespan. Upon inspection, it turned out that oxidation on the negative terminal caused poor contact, and sanding it down fixed the problem. Additionally, frequent short-distance driving doesn't allow the battery to charge sufficiently, so using a charger to top it up a few times can help. Fuel quality is also crucial—gasoline from small stations often contains impurities that can clog the fuel pump's filter screen, leading to poor fuel supply. It's advisable to install a battery voltage monitor and address any issues promptly if the voltage drops below 11 volts.
