compression test

[1979jimmy350]

would it be ok to do a compression test with the exaust manifolds off? i thought it might be easier to do it while i am putting on hedders. Also should i have all the plugs out at the same time or should i only take the one out that i am doing the test on

 

[diesel4me]

Having no exhaust manifolds wont matter.I'd pull all the plugs,it lets the motor spin over faster--its also best to check the compression while the motor is still warmed up,you get a more accurate reading that way--but its not absolutely nessasary .Look for consistency rather than a certain pressure--if one cylinder is more than 15-20 lbs lower than the others,that one has a problem--they should be about 125-150 lbs on a healthy engine. /forums/images/graemlins/crazy.gif

 

[ryoken]

as Rob said, don't matter.. pull the plugs... should be within 10% of each other..

if you have a low cylinder when all done, squirt some Marvel or tranny fluid in that one and do it again.. if the number goes higher than the last time, you've got a ring prob and not a valve issue... /forums/images/graemlins/peace.gif