Where did you find an adapter for your compression tester or did you have to buy another one? I have not been able to find one locally that will fit the Stang.Heres how you do a proper test, first the motor should be warm, shut off the fuel by either pulling the pump fuse/relay or inside the trunk, right near the inertia switch give the brace a whack with a rubber mallet to get the switch to trip, (red button pops up), disable the ignition by unpluging the crank sensor, its right below the A/C compressor. Next, remove ALL the plugs and somehow lock the throttle body plates wide opened then proceed to test each cylinder giving it about 3-4 bumps on each. Record each one and compare at the end, good luck.
The threads on my tester are 14mm and 18mm and the threads on the plugs holes is 16mm. So far I've not been able to find an adapter or a new guage that has the 16mm threads. My tester is an older Craftsman.I know I didn't have to buy anything extra, my tester is older and has just about everything you could ever need. Why won't yours fit, the threads in the head are standard, just deep in there.
Calling all 05+ mustang experts. Are all the plugs in the new stangs 16 mm? I tried my compression tester in the heads of my stang and the two adapters, 14mm and 18mm do not fit. The 18mm is too large and the 14mm is too small and I have yet to find anyone who makes a 16mm adapter except Snap-On and they want $ 46.00 for one which is rediculous. Am I dreaming or did Ford really do this?Geez, I don't know what to tell you, 14mm is the standard size plug. The older Fords use an 18mm plug. I did happen to see a new guage at Sears tonight and it comes as 14mm, 18mm and a 14mm long reach adaptor, are you sure the threads in your head weren't screwed around with (no pun intended) or stripped.