How to Test the Compression on a Toyota 22RE

A compression test reveals a lot about internal engine conditions.

Compression is a good indicator of how worn an engine is on the inside, which gives you a clue as to how much life it has left. Additionally, engine compression gives an indication of whether a problem exists with the valves, rings or head gasket. This is a great test to do before buying a used Toyota 22RE or, for that matter, any used vehicle.

Difficulty:

Moderately Easy

Instructions

things you'll need:

• Compression gauge

1. • 1

     Start the engine and let it warm up. Compression readings are only valid if the engine has reached its normal operating temperature. Once that occurs, turn off the engine.

   • 2

     Remove the spark plugs. Be careful -- the engine and the plugs are hot!

   • 3

     Connect the compression gauge to one of the cylinders. The order in which you test the cylinders does not matter.

   • 4

     Turn the engine over with the throttle wide open until the compression stops rising. This will take just a few seconds. Don't worry about the engine starting -- it cannot start with the plugs removed.

   • 5

     Check the compression gauge. Write down the compression reading and the cylinder that you tested.

   • 6

     Repeat steps 3-5 for the other three cylinders in your Toyota.

   • 7

     Compression for a Toyota 22RE cylinder should be between 142 psi and 178 psi. In addition, no more than 14 psi difference should exist between the highest and the lowest cylinder readings. For example, a reading near 170 for all four cylinders is fine and a reading near 150 for all four cylinders is fine; but one cylinder at 170 psi and another at 150 psi is not fine. Keep in mind, too, that although 142 psi is acceptable, it suggests that the engine is well worn and may soon need to be rebuilt.

Tips & Warnings

• Some compression gauges screw into the spark plug socket; with other models, you press the gauge into the socket and hold it in place while the engine is cranked. If you have the first type, you can do the compression test yourself. With the second type, you will need a helper -- one person cranks the engine while the other holds the compression gauge.

• Make sure your clothing, jewelry and hair do not get caught in any of the moving parts under the hood. Automobile engines have components that may start and stop without warning, sometimes even when the motor is turned off and the spark plugs have been removed.