Compression Test

[Anxious]

Does anyone know how to do a compression test on our engine? I've got almost 90,000 miles and was curious to see what shape my engine is in. Autozone has the compression testers but I don't really know how to use one.:confused:

[Seawulf]

I think you just pull out all the spark plug wires then undo one spark plug at a time and screw the end of the tester into the hole and crank the engine over. You'll need some one to either read the dial or crank it over. I think around 180 is standard compression.

[Anxious]

Thanks seawulf, that seems easy enough!

[Afterhours]

You can remove all of the plugs if you want to take the load off of the starter & battery.....not really necessary, but some people prefer to do it that way (since you'll eventually need to pull all the plugs out anyway to do the compression test).

1) Disable the ignition system

2) You want to set the throttle plate fully open (wide open throttle position).

3) Install a screw-in type compression tester to cylinder #1, then crank engine for at least 5 compression strokes (approximately 5 seconds) and record the highest reading on the gauge.

4) Repeat the test on each cylinder.

5) Compare the highest reading from each cylinder to each other. The compression is considered within specs if the lowest cylinder reading is within 75% of the highest cylinder reading.

[Seawulf]

Yeah, do what Afterhours said.