2001 7.3 smoking blue, the whole time its running

[jbuller]

ok

i need to know how to tell if you are having valve problems or ring problems? can you tell with the compression tester? or is there another method to telling the difference, those are the two things that could be causing my hard start problem and my blue smoke problem. i want to know what is my problem so i can either pull the heads off and redo them or pull the motor out and throw new rings in it. Thanks for your help.
Jay

 

[BJS]

Written for a gasser but you get the idea.

When conducting a compression test, the tech is trying to determine what cylinder/s have low compression and possibly worn piston rings. During a typical test, the tech might note that on a six-cylinder engine, the actual reading is low in comparison to factory specs. For instance, the book calls for 140 PSI per cylinder; actual readings show between 70 to 80PSI. That's low! Now the tech squirts oil into each cylinder to see if the reading comes up. If it does, that's an indication of worn piston rings. What happened is that, when the oil was squirted into the cylinders, it (the oil) filled the gaps from wear around the rings, resulting in increased compression readings. The tech now knows that he must remove the cylinder heads for closer inspection of the engine. During a cylinder leakdown test, the tech injects compressed air into each cylinder through the sparkplug hole. While this air is flowing into the cylinder, the tech inspects for where the air is escaping. If it's found to be escaping into the oil pan, then the tech knows that the rings are worn, resulting in air leakage into the crankcase; further tear-down is necessary to determine the extent of internal wear.