Car Stalls While Driving and 8 Common Causes
When your engine suddenly stops while driving, it’s both stressful and frustrating. It leaves you stranded and requires costly repairs. Your engine may stall when starting, stopping, idling, or even while driving at highway speeds, but there isn’t always one cause.
Find out the most common reasons why your car stalls and what to do when it happens so you can get going again.
What does it mean when your car stalls? The term “standby” is used to describe the sudden loss of power to the vehicle’s operating system. Stalls can occur for a variety of reasons, including mechanical and electrical.
In some cases, your vehicle may be able to restart without any issues after stalling. However, in some cases, your vehicle may not even be able to start. Either way, a stalled vehicle is a cause for concern and should be addressed as soon as possible. If a stall occurs at cruising speed, it can be a safety hazard. What causes a car to stall?
A vehicle can stall for a variety of reasons. Below are some of the most common reasons, all of which are cause for concern:
1) Fuel System Issues
A problem with your vehicle’s fuel system can cause it to stall almost immediately. This type of issue is most commonly caused by a loss of fuel pressure. This condition can be caused by a failed fuel pump, a significant fuel leak, or a clog in the fuel system itself. In either case, insufficient fuel pressure/supply will prevent the engine from achieving proper combustion.
2) Charging System Issues
Once the vehicle is started, the engine charging system keeps the engine and components running by providing voltage. The most important component in this system is the vehicle’s alternator, which typically provides 13.5 to 14.5 volts during normal operation.
However, if the alternator is defective, it may supply a significantly reduced voltage, causing the battery to discharge rapidly. Such a discharge can cause the vehicle to stall after a short period of time, even if it has a relatively new battery.
3) Ignition Spark Issues
Gasoline engines rely on a supply of spark to ignite the air-fuel mixture in each cylinder. If this spark suddenly disappears, the engine will stall.
Faulty ignition coils, worn distributor caps, and damaged rotor knobs are all common causes of spark loss that can lead to stalling. Such issues can occur at any speed or at idle.
4) Sensor Issues
Issues with certain sensors can cause the engine to stall. This occurs when unreasonable, incomplete, or inaccurate data is provided to the engine management software.
The most common sensors that can cause an engine stall include the Engine Coolant Temperature Sensor (ECT), Mass Air Flow Sensor (MAF), and Throttle Position Sensor (TPS).
In addition, issues with the vehicle’s throttle body or idle air control valve (IAC) can also cause the engine to stall.
5) Vacuum Leaks
A vacuum leak is most accurately described as the introduction of unmetered air into the engine.
A large vacuum leak can cause the vehicle’s engine to run lean, meaning there is insufficient fuel supply to balance the amount of air in each combustion chamber. This can cause the engine to stall intermittently.
This type of problem is often most noticeable during cold weather start-ups, as a richer fuel mixture is required when driving.
6) Stuck Belt-Driven Ancillary Equipment
The sudden failure of a belt-driven auxiliary component can also cause the vehicle to stall. A seized part, such as the air conditioning compressor or power steering pump, can put resistance on the engine’s drive belt.
If the belt itself does not break, it can also put excessive resistance on the engine’s crankshaft pulley. This can cause the engine to stall and shut off.
7) Motor Control Issues
The majority of today’s internal combustion engines are equipped with a timing chain or timing belt. These belts/chains synchronize the engine timing between the crankshaft and upper components.
If a timing chain or belt stretches or breaks, it can cause the engine timing to be thrown off and the engine to stall. In the most extreme cases, a broken timing belt or chain can cause serious damage inside the engine.
8) Transmission Problems
In some cases, serious problems with the transmission can cause the engine to stall. This type of failure puts too much stress on the engine, basically causing it to stall.
Clutch problems (manual) and torque converter problems (automatic) are among the most common of these failures. Either way, this type of problem can get worse over time.
What should I do if my car stalls while I’m driving? If your car stalls while you are driving, the first thing you should do is stay calm. It may seem natural to panic in such a situation, but staying calm is important to end such an accident safely.
When your vehicle stalls, you will lose all power steering and power brakes, so you will have to perform both functions manually. Start applying the car’s brakes evenly and properly. Excessive braking can cause skidding, further complicating the situation.
You should also find a safe place to stop, which is often the shoulder of the road. When it is safe, pull over carefully to the shoulder with your turn signals on. Once you reach the shoulder, continue to brake until your vehicle comes to a complete stop.
As soon as you have stopped, put your vehicle in Park (automatic) or Neutral (manual) mode and apply the emergency brake. If the cause of your vehicle’s stall cannot be easily determined and cannot be repaired on the side of the road, call a tow truck to transport your vehicle to a service facility.
Does Stalling a Manual Transmission Car Damage It?
Many who are new to driving a vehicle with a manual transmission, deal with difficulties when attempting to take off at a stoplight, or when easing into a parking spot in reverse. If the correct amount of throttle/clutch is applied, a vehicle of this nature will stall, requiring a restart.
The question is, does stalling a manual transmission cause damage. The short answer to this question is “no”. While stalling a manual transmission is certainly not ideal, it is unlikely to cause any notable damage, unless done repeatedly over the course of several years.
At worst, repeated stalling might finish off aging components within the driveline that are already approaching the point of failure. However, most drivers will master the use of a manual transmission far before any damage can be sustained.