Hello everyone, So I have a 2007 F-150 5.4. number 6 cylinder is dead. replaced coil and spark plug, still dead. decided to check compression and cylinder leakage. leak down test showed 20 percent. compression showed 75 psi. It seems to me that if you have 20 percent leakage you should have more that 75 psi compression or am I wrong?

 

Was the throttle open or closed during the compression test?

 

this and what did the other cylinders read to compare against

 

Tried it both ways, didn't seem to matter.

 

The number seven cylinder next to it had 150 psi.