I drive a 4.2L 89YJ with a bad "tick,tick,tick" sound. Here's what's happening...When I first start the Jeep, and the engine is good and cold there is no "ticking".Halfway to normal operating temperature it starts to tick a little and gets progressively worse as it warms up. At normal temp. the ticking is loud and annoying.(I avoid the drive-thru)The noise never becomes constant.It ticks for a couple seconds then stops for a couple of seconds. When I first listened to it, with the hood up, I thought for sure it was a lifter. But I've noticed that the noise seems even louder when listening under the jeep.Could this still be a lifter? Can anyone tell me without actually hearing it?