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Old 09-18-2003, 09:55 PM   #6
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Originally posted by wolfman
ANY engine will test higher WARM due to the thermal expansion of the pistons/cylinder walls and valves. I test COLD because I want to know what the engine is doing at it's WORST not it's best. (Even full blown AIDS patients have "good" days) Screwing things in and out of warm aluminum spark plug holes is also NEVER a good idea...
From Saturn FSM Book Engine Mechanical, page 22:

Compression Check

1. Start the engine and allow it to reach normal operating temperature.

2, Shut engine off and disconnect the ignition module wiring harness plug.

3. Disconnect spark plug wires and remove all four plugs.

4. Insert compression gage bar kit SA9127E into the spark plug hole.

5. Fully open throttle (TBI and MFI)

IMHO, you aren't getting accurate numbers unless you are collecting information with your car at temp. Saturn's spec numbers represent the motor at temperature and wouldn't give you a reasonable unit of measure if you're gathering the information cold. I want to know what my car is doing when it's running under normal conditions. Once started, it doesn't stay cold long.

One of the very few times I disagree with you , Wolfman.
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