jeep 4.0 lifter sticking like oil has not been changed properly, I changed added a quart marvel mystery oil.It stops every now & then runs real nice after 600 miles of this treatment,but as soon as it hits 55 to 70 mph it starts back,off/on valve starts back clicking, I drive around a little the next time I start up it may quit again the oil pressure ok for 178000 miles on engine no smoke fine other than this off on sticking lifter do you have any tricks other than tearing down? Thanks mooch