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Drivability symptoms effect a vehicle's ability to be driven as usual, but can't always be seen, heard, or felt.
Starting trouble applies to any time when the engine is being started.
A no-start condition can apply to a vehicle where the starter won't crank, or where the starter cranks but the engine won't start.
If a vehicle is having trouble starting, it will start eventually, but can be temperamental, or take longer than normal to start.
If the starter will not disengage, it can be heard as a loud metallic grinding, and requires the engine to be turned off.
A mixture problem is when the air to fuel ratio is not correct. If an engine is running with too much fuel, it is known as running rich. If an engine is running with little fuel, it is known as running lean.
If an engine is running with too much fuel, and too little air, it is known as running rich.
If an engine is running with too little fuel, and too much air, it is known as running lean.
Any noises that seem to be abnormal should be considered symptoms.
Anything that can't usually be felt, but is noticed should be considered a symptom.
Any smells that seem to be abnormal should be considered symptoms. These odors could be present anywhere near or in a vehicle.
Anything that appears abnormal should be considered a symptom. Visual symptoms could present themselves as leaks, smoke, warning lights, and more.
Idle is when an engine is operating at minimum speed, without throttle applied, and without the transmission engaged. An engine should idle at a steady speed, often around 700rpm.
When an engine's idle drops below the normal speed, and then rises again to the normal speed, it is known as an idle hunt. Idle hunts do not raise the engine speed above the normal level, as opposed to an idle surge. An idle hunt can only occur without throttle applied, or the transmission engaged.
An engine should idle at a steady speed. Surging and fluctuation is when the speed rises above the normal idle speed and drops to or below the normal idle speed, without throttle applied or the transmission engaged.
A regular idle speed is generally from 600-900rpm. You may reference your owner's manual to determine if your idle speed is above normal.
A regular idle speed is generally from 600-900rpm. You may reference your owner's manual to determine if your idle speed is below normal.
Loping is very similar to idle surging and fluctuation, when the engine speed repeatedly rises above the normal idle speed and drops to or below the normal idle speed. Loping can occur with or without the transmission engaged.
Stalling is when the engine dies without being purposefully turned off.
Misfiring is when a cylinder does not operate as normal and the air/fuel mixture does not explode. It can be felt through vibrations and slight hesitation, and also can be heard in inconsistencies in engine and exhaust sound.
Hesitation and stumble are felt as sudden momentary lack of power, as if the car is hesitating to accelerate.
Surging is when the car accelerates repeatedly with the accelerator held steady. It can be felt like the accelerator pedal is being pumped repeatedly.
When an engine cuts-out, it loses all power, similar to a severe hesitation or stumble, but without the engine dying. Cut-out can be temporary or require the engine to be restarted.
Poor acceleration is felt as a lack of power when accelerating, resulting in a slow rise to a desired speed. More acceleration is necessary than usual.
Loss of power can occur during acceleration or cruising speed. More throttle is necessary than usual to arrive or stay at a desired speed.
Backfiring is heard as a loud explosion coming from the exhaust, or sometimes even through the intake system.
Engine run-on or dieseling is when the engine will continue to run after the ignition is turned off.
When an engine overheats, the temperature gauge can be seen as higher than normal, and also coolant can leak from the cooling system pressure cap, causing steam if contact is made with the hot engine.
If an engine takes much longer than normal to warm up, this can be seen on the temperature gauge, and can result in slow heater warm-up, poor economy and engine performance.
This is felt only in gear, as the engine revving but road speed not increasing, and usually only a temporary occurrence.
Vibration can be felt through the seat, steering wheel, shifter, pedals, or anywhere else in the car as a very fast shaking.
This can apply to pedals, shifters, steering wheels, or other vehicular accessories that are manually operated.
This can apply to pedals, shifters, steering wheels, or other vehicular accessories that are manually operated.
Lurching/Bucking can be felt as violent forward and backward shaking of a car when moving.
Shaking can be felt as a violent side to side or forward and backward rocking of a car when moving.
Chatter/pulsation is similar to vibration, but is usually felt in pedals as a rapid and repetitive up and down pressure.
Veering can be seen when a vehicle drifts to the left or right, with the steering wheel held straight.
Pulling can be felt when a steering wheel and car has a tendency to pull left or right.
Grabbing can be felt, for example, when the brakes are pressed lightly, but it seems like they are applied with much more force.
Bouncing can be felt after driving over bumps, as the car continuing to bounce up and down longer than normal.
Bottoming out can be felt as the bottom of the car hitting the road when going over minor bumps, that normally would not cause the car to hit the ground.
Dragging can be felt as the car being slowed down more than usual, as if dragging against the road.
Smoke can be seen coming from different locations on a vehicle, but usually the exhaust. The color of the smoke can identify specific symptoms.
Electrical symptoms can be presented as anything from headlights not functioning, to a "Check Engine" light appearing in the dash.
This includes any lights, either exterior such as a headlight or tail light, or interior such as a cabin light not functioning.
Vehicular electrical accessories could include radios, cigarette outlets, car alarms, aftermarket electronics, and more.
Malfunction indicator lamps are used by cars to alert drivers of any problems with the vehicle.
- definition and more information -


  

Directions:
Check engine light come on? Having transmission problems? Need auto repair? Or maybe just a tune up for your car? Find out what you need by selecting any symptoms presented by your vehicle, using the "symptom navigator" to the right. You may select any and all symptoms presented, whether or not they are related, or have a common root cause.

If you are unsure about any specific symptoms, you may move your mouse over the "?" to view a definition and more information.

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