For 1990-2009 cars

Perform the following steps in order to conduct a compression test:

1. Conduct the following steps in order to check cylinder compression:

1.1. | Engine should be at room temperature.

1.2. | Remove the ignition and both the fuel injector fuses from the underhood electrical center.

1.3. | Remove the spark plugs.

1.4. | Battery should be at or near full charge.

2. For each cylinder, crank engine through four compression strokes.
3. The lowest reading cylinder should not be less than 70% of the highest.
4. No cylinder reading should be less that 689 kPa (100 psi).

Important: The results of a compression test will fall into the following categories:

1. Normal -- Compression builds up quickly and evenly to specified compression on each cylinder.
2. Piston Rings -- Compression low on first stroke. Tends to build up on following strokes but does not reach normal. Improves considerably with addition of oil.
3. Valves -- Compression low on first stroke. Does not tend to build up on the following strokes. Does not improve much with addition of oil. Use approximately three squirts from a plunger-type oiler.
4. Head Gaskets -- Leaking head gaskets give nearly the same results as valve problems. Engine coolant may be recognized in the crankcase. Head gasket leaks between two cylinders will give low compression readings on both cylinders.