For 1990-2009 cars

Perform the following steps in order to conduct a compression test for the L61.

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

1.1. | Engine should be at room temperature.

1.2. | Disconnect wiring from the ignition module.

1.3. | Remove the spark plugs.

1.4. | Throttle body valve should be wide open.

1.5. | 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 than 689 kPa (100 psi).

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

• | Normal - Compression builds up quickly and evenly to specified compression on each cylinder.

• | 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.

• | Valves - Compression low on first stroke. Does not tend to build up on the following strokes. Does not improve much with the addition of oil. Use approximately three squirts from a plunger-type oiler.