A crank sensor, also called a crankshaft position sensor, is a vital part of the engine of the 2000 Pontiac Sunfire. The sensor calculates the revolutions per minute (RPM) of the engine and the firing order of the engine cylinders, allowing the engine to run smoothly and efficiently. Problems with the crank sensor can cause issues with your engine and the way your Sunfire runs.
One symptom of the crank sensor malfunctioning is if the car won't start. A bad crank sensor won't allow the cylinders to fire properly. You will hear the starter trying to ignite but the car will not be able to fire up the engine.
Another sign of the crank sensor going bad on your Sunfire is if the engine starts misfiring. The car may run very roughly as a result. Chronic misfires could harm your engine and result in expensive repair costs. Your car's emissions may also increase and could result in your car failing an emissions test.
With the engine misfires and performance problems that result from a bad crank sensor, the fuel economy of your Sunfire will suffer. According to the U.S. Department of Energy website, a 2000 Sunfire in optimal condition is estimated to get an average of 23 miles per gallon with 19 miles in the city and 28 on the freeway. While a Sunfire on the actual road likely does not get those numbers, the fuel economy will decrease dramatically as the crank sensor fails.
Another sign of a bad crank sensor is the car suddenly stalling. With the timing of the cylinders off and the RPMs not where they should be, the engine can stop running at random times. It will usually start running roughly before it dies and the car may shake. Shortly thereafter, the car may shut down and require a restart.
Problems in the engine normally result in the "check engine" light coming on and the crank sensor is no different. Once the engine starts misfiring and not getting the RPMs that it needs, the computer should register a repair code for the crank sensor and the "check engine" light will come on. It may turn on and off intermittently until the sensor is replaced and the engine is running normally again.
