How to Check an Engine RPMby Alibaster Smith
RPM, or revolutions per minute, refers to the vehicle's engine speed--or rotational force--in your vehicle. The RPMs in your automobile are measured by a rev counter called a tachometer.Though some vehicles are not equipped with a tachometer from the factory, most vehicles are. To check your engine speed, or RPMs, you'll need to have one of these gauges installed on your vehicle. The tachometer can also serve as a simple diagnostic device, letting you know whether the engine is spinning too fast. Every tachometer is equipped with a "redline," the number on the gauge that indicates the engine is spinning faster than it was mechanically designed to. To ensure you maintain optimum engine speed and that you do not damage your engine, you'll need to know how to check your vehicle's engine RPM.
Turn your vehicle's ignition key to the "II" position on the face of the ignition cylinder and lock assembly. This will illuminate all of the dash lights in front of you. Turn the key to the "III" position, and the engine will begin to crank. When the engine starts, let go of the key.
Look directly in front of you on the dash, behind the steering wheel. There will be two large gauge faces. The gauge face on the right is normally the speedometer and measures the speed of your vehicle. The gauge face on the left is your tachometer. Normally, in the center of the tachometer you will see "x 1000," or the designation "RPM," or both printed on the gauge face.
Press the accelerator pedal (the right-most pedal in the driver's side foot well) while the vehicle is still in neutral or park. You will see the needle on the left gauge face moving. This indicates engine speed. For example, if the needle is pointing to the "1" on the tachometer, it means your engine is spinning at 1,000 revolutions per minute. Most engines spin at roughly 1,200 to 1,500 RPMs when the engine is first started in order to warm up the engine cylinders. The engine speed will then drop to about 800 RPM. As you drive, periodically check your engine RPM by glancing at the left gauge.
- Do not rev your engine beyond the red mark on your tachometer. This mark indicates the upper limit of your engine's capabilities. Revving beyond this point will trigger an automatic engine shut off to protect the engine from serious damage. However, repeated attempts to rev the engine at or past the redline can cause premature engine wear and eventual failure.
- Auto Repair For Dummies; Deanna Sclar; 1999
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