Car started to run like crap so I pulled the plugs and found oil on the drivers side spark plug, closest to the front of the car. Is that piston #5? So I want to do a leak down test and don't have experience doing this. I just bought a harbor freight leak-down tester. What's the proper procedure to get the piston to exactly TDC for a leak down test? I couldn't find how in the service manual. Do I turn the crank w/ a ratchet clockwise? counterclockwise? does it matter?