Did I perform my compression test correctly?

early99powerstroke

New member
Joined
Jun 12, 2011
Messages
149
Reaction score
0
I brought my 7.3 powerstroke up to operating temp. removed the valve covers and unplug the injectors and glow plugs. I then removed the glow plugs. I cranked the motor over 10 times to evacuate any oil that could have fallen into the cylinders. I then hooked up my compression gauge up to each cylinder cranking the motor over ten times for every cylinder. Did I do this correctly? my readings were between 350psi - 380psi.
 

CSIPSD

New member
Joined
May 18, 2011
Messages
5,284
Reaction score
5
Location
Bend, OR
Sounds about right... A little over done. The numbers should have stopped moving at about 3-5 rev but...
 

Aaron S

New member
Joined
May 22, 2011
Messages
169
Reaction score
0
I agree with that method. Ive been told to perform the test warm aswell. I wonder if anyone has had enough patience to do it both ways and see if there is any difference?
 

Aaron S

New member
Joined
May 22, 2011
Messages
169
Reaction score
0
Makes sense. Low compression seems to cause the biggest issues with cold starting and excessive smoke when cold.
 

early99powerstroke

New member
Joined
Jun 12, 2011
Messages
149
Reaction score
0
What i'm worried about though is the little amount of oil that could have gotten into my cylinders when i pulled the glow plugs cuz i didn't have an air nozzle and air compressor to remove the excess oil. So i cranked the motor over 10 times before hooking up my compressio gauge. Would that remove all the oil so it wouldn't mess up my readings? Thanks!!
 
Top