I'm trying to do a compression test on my 98 4.6 GT. I haven't been able to get it threaded into any of those deep holes. Does anybody have a trick to get it started?
Ensure you have the right thread pitch adapter. My personal kit has multi to choose from.
Check it against your spark plug.
Then I recommend turning the adapter counter-clockwise and then clockwise to get it to start.
Good luck!
I just got a new gauge with a 14mm thread and I still can't catch any thread. I'm not familiar with this engine, but you must need something special. How deep do the threads start? I just need to get compression on a dead hole to go forward.
That's not what I'm saying. I'm saying if the engine has sat for a long time and is now dry-firing for the sake of a compression test, add a bit of oil to the cylinder.
I finally found a YouTube video where the guy says you need an extended adapter to catch the threads. There aren't any locally, I ordered one from Summit. I'm surprised nobody knew that.
I didn’t realize you were trying to use a short threaded adapter. If you compare how deep the threads are on the plug, you’ll see that the short adapter won’t work.
I apologize for not mentioning that, but that’s kind of what I meant by making sure you had the correct thread. Pitch and depth are both critical.