Proper way to test compression.
 

I'm A Noob! I've got what appears to be a fine running '88 with a N/A 13B (116k). I'm getting ready to sell the engine. (Buick GN conversion) I want to check the compression on the 13B before removing it and advertising it. I used the search feature to learn the proper way to test the compression. I couldn't find anything.
Can someone explain how to do it without any special equipement? I've got a reqular old compression tester. What kind of numbers should I get? What would be a fair asking price for the motor and (auto) tranny? It doesn't smoke and drove 200 miles home fine. It even started at 20 below zero this last winter! Dave C.

Well, the correct way would be to take it to the dealer and have them use the special tester on it. But the method that most of us use, is to plug in a regular old tester, and hold the pressure release valve open while somebody spins the motor. Usually anything above 90 PSI is considered acceptable.

so ur saying to hold down the pressure release valve before cranking? i thought you were to hold it down in the middle of cranking? my compression tester doesn't have that schrader valve inside so i think im ready to go:rock: