A sudden stall while driving is both stressful and frustrating, leaving you stranded and facing pricey repairs. Stalling can happen when starting, stopping, idling or even at speed, with no single culprit behind every case.
We’ll explore the most common reasons that cars stall and what you should do if it happens so you can get rolling again.
What Does it Mean When a Car Stalls?
The term “stalling” is used to describe the sudden loss of power to a vehicle’s operating systems. Stalling can happen for several reasons, some of which are mechanical in scope, while others are of an electrical nature.
In some cases, a vehicle will restart without issue after stalling. However, at other times, a vehicle may crank to no avail.
In any event, vehicle stalling is cause for immediate concern and should be addressed as soon as possible. If stalling were to take place at cruising speeds, one’s safety could be compromised.
See Also: 7 Causes of a Car That Starts Then Dies
Reasons a Car Stalls
A vehicle can stall for many different reasons. The following are several of the most common of these reasons, all of which are cause for concern.
#1 – Fuel System Issues
Any issue within a vehicle’s fuel system can lead to near-immediate stalling. Issues of this type most commonly include a loss in fuel pressure.
This condition can be caused by a failing fuel pump, severe fuel leak, or an obstruction within the fuel system itself. In any case, a lack of fuel pressure/delivery prevents an engine from achieving proper combustion.
#2 – Charging System Issues
Once a vehicle starts, engine and component operation is sustained through the delivery of an engine’s charging system voltage. The most critical component within this system is a vehicle’s alternator, which generally provides 13.5-14.5 volts under normal operation.
However, a faulty alternator can provide significantly less voltage, leading to rapid battery discharge. Such discharge can lead to vehicle stalling in short order, even with a relatively new battery.
#3 – Spark-Related Issues
A gasoline engine relies upon spark delivery to ignite the air/fuel mixture within each cylinder. If this spark suddenly ceases, engine stalling will occur as a result.
Faulty ignition coils, deteriorated distributor caps, and damaged rotor buttons are all common sources of spark loss, which have the ability to induce a stalling condition. Such issues can occur at any speed, or at idle.
#4 – Sensor Issues
Issues with certain sensors can, and will induce engine stalling. This occurs when irrational, incomplete, or incorrect data is provided to an engine’s management software.
See Also: Code P0133 (Oxygen Sensor Issue)
#5 – Vacuum Leaks
A vacuum leak is most accurately described as the introduction of unmetered air into an engine.
Large vacuum leaks can cause a lean condition within a vehicle’s engine, meaning that fuel delivery is insufficient to match the volume of air within each combustion chamber. This, in turn, can lead to stalling at random intervals.
Problems of this nature are often most noticeable at start-up in colder weather, as a richer fuel mixture is required for operation.
#6 – Lockup Of Belt-Driven Accessories
The sudden failure of belt-driven accessories can also lead to vehicle stalling. When such components, such as an A/C compressor or power steering pump lock up, resistance is placed upon an engine’s drive belt.
If the belt itself does not snap, excessive resistance will also be placed upon the engine’s crank pulley. This, in turn, can smother an engine out, putting it into a stall in the process.
#7 – Timing Issues
The vast majority of today’s internal combustion engines feature timing chains or timing belts. These belts/chains synchronize the timing between the engine’s crankshaft and top-end components.
If a timing chain or belt were to stretch or break, an engine’s timing can shift, causing a stall. In the most extreme cases, the breakage of a timing belt or chain can lead to severe internal engine damage.
#8 – Transmission Issues
Occasionally, severe transmission issues can result in engine stalling. Failures of this type put excess strain on an engine, essentially bogging it down as a result.
Clutch-related problems (manual) and torque convertor issues (automatic) tend to be among the most common of these failures. In any event, problems of this nature are likely to worsen with time.
What Should You Do If Your Car Stalls While Driving?
If your car were to stall while driving, the first order of business would be to remain calm. Though panicking would seem natural in such a situation, keeping your composure is key to bringing a misadventure of this type to a safe resolution.
When stalled, a vehicle loses all power steering and power braking, meaning that both functions must be completed through manual force. Begin applying your vehicle’s brakes at a steady, yet reasonable rate. Over-braking will induce a skid, thereby further complicating matters.
You should also look for a safe place to pull over, which in most cases will include the shoulder of the roadway. After checking to ensure that it is safe to do so, carefully merge over onto the shoulder of the road, while using your vehicle’s turn signal. Upon reaching the shoulder, continue braking until your vehicle comes to a complete stop.
Once stationary, place your vehicle in park (automatic) or neutral (manual) and set the emergency brake. If the source of your vehicle’s stalling condition can not be easily identified and repaired roadside, call a wrecker to have your vehicle transported 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.