Understanding Your Vehicle’s Drivability (Questions You Should Be Asking Yourself As a Car Owner)

If a vehicle has issues, sometimes it’s time to think about whether or not it’s still driveable. Drivability pertains to a vehicle’s ability to be driven, but it can also be a measure of the vehicle’s condition in terms of whether it can reliably function as a form of transportation.

Keep in mind that your vehicle has onboard diagnostics and various sensors. The vehicle’s check engine light typically activates when the computer detects issues and would typically store a trouble code in its computer, which you can use to diagnose the issue. The check engine light is a good indicator that your vehicle has an issue and isn’t in the most drivable state.

If a vehicle has issues such as excessive vibration or stalling, then it’s less drivable compared to a vehicle that doesn’t have these problems. A vehicle’s drivability is inversely proportional to the number of issues it has. Questions about drivability are most relevant when a vehicle is being bought or sold. Service professionals typically inspect a vehicle with specific questions in mind to determine the vehicle’s drivability.

Questions to Ask About Drivability

Does the Vehicle Crank During Startup?

A no-crank condition happens if the vehicle’s engine or starter doesn’t crank when the key is turned. This could be caused by a faulty starter motor, a flat battery, a faulty ignition switch, or a seized engine. The vehicle’s security system could also prevent the vehicle from starting. This could happen if, for example, the right key isn’t inserted into the ignition switch.

Does the Vehicle Crank but Not Start?

The engine is the vehicle’s most fundamental component and if it isn’t able to start then the vehicle simply isn’t drivable. You should be able to drive your vehicle whenever you want. If it doesn’t start when you turn the key, then your vehicle’s drivability will suffer.

For the vehicle to start, power needs to flow from the battery, through the starter relay, and into the starter motor, among other complex functions. However, the engine won’t start if there are issues with components like the fuel pump, ignition system, or electronics.

Does the Vehicle Start but Stall?

A vehicle’s engine should only turn off when prompted by the driver. If the engine can’t run continuously, then it significantly affects the vehicle’s drivability.

Does the Vehicle Stall When It Comes to a Stop?

If the engine shuts off when the vehicle is slowing down, then it’s dying on deceleration. This problem can be caused by a broken idle air control motor, a dirty throttle body, a defective or failing throttle position sensor, a faulty transmission, or an exhaust gas recirculation (EGR) valve that’s stuck open due to carbon buildup. A vacuum leak could also cause this issue.

Does the Vehicle Hesitate or Stall While Accelerating?

Hesitation/dying on acceleration happens when the engine hesitates or stalls even when you’re pressing hard on the throttle pedal. The engine might also shudder before it stalls. This problem is typically caused by a faulty fuel pump, a faulty mass air flow sensor, or other faulty engine sensors.

Does the Vehicle Stall Intermittently?

There are some instances where the engine will stall without any perceivable pattern and refuse to restart. Common causes include a faulty crankshaft position sensor, camshaft sensor, fuel pump, or fuel relay.

Does the Vehicle Lack Power?

Sometimes, a vehicle will also refuse to produce power when traveling at high speed or going uphill. This can be caused by a clogged air filter or a clogged catalytic converter. Obstructions in the engine’s intake and exhaust system can also affect a vehicle’s performance.

Does the Vehicle Misfire Under Load?

If you hear loud pops or bangs coming from your engine or exhaust when accelerating or going uphill, then your engine might have a misfire under load condition. Misfires are also accompanied by an illuminated or flashing check engine light. This issue is often caused by faulty ignition components like spark plugs, distributor caps, or ignition coils.  Lack of fuel from the fuel pump or a clogged fuel filter could also be a problem. A faulty mass air flow sensor or a clogged catalytic converter could also be the culprit. This issue can even be caused by sludge buildup inside the engine due to old oil.

Misfiring under load also is usually accompanied by a flashing check engine light.

–Anthony Harlin, ASE Certified Master Automobile Technician

Many of these drivability questions are due to the faulty condition of the drivetrain and its components. If you’re looking to buy or sell a vehicle, resolve these problems before you make a deal. If your vehicle has drivability issues, ask a trusted mechanic to check it out and repair its problems.