Okay I know how to check compression on an engine that's still in the car, but is it possible to Compression check an engine that is already out of the vehicle? I mean some ppl post up compression on an engine that is already out of the car....So did they check it before they pull it out or they check it some how some way??? Thanks in advanced.

 

You can check it out of the car by hooking the started up to it and using a jumper battery. However, the engine will not be warmed up and the readings may be different than they would be if it was.

 

Thanks...