Car sputtering when at idle


I have a 2000 Ford Explorer with a 4.0 engine. Last April I had the head replaced because it was cracked. Now I am losing water/antifreeze from my overflow tank, the car overheated once and they replaced the thermostat. The check engine light came on and I took it to Auto Zone and they scanned it and it came up with the 6 cylinder was misfire. We checked the spark plugs and that one was cracked so it was replaced and they put silver soder in to help with the leaking water out of the resevour. I took it to a mechanic and they did a pressure test on it and could not find a leak anywhere. The car sputters a little when you first start it up but then smooths out except when it is idleling at a stop light or something. Do you have any ideas? Do you think it might be the head again?


Doubt it could be the head again. Sounds like it has a small vacuum leak. Check all of the hoses around the intake manifold, one or more can be split or not on properly.