Perform the following steps in order to conduct a compression
test for VIN 4:
- 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. |
- For each cylinder, crank engine through four compression strokes.
- The lowest reading cylinder should not be less than 70 percent
of the highest.
- 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 addition
of oil. Use approximately three squirts from a plunger-type oiler. |