Agree with the first poster - use a manual gauge to verify the sender / pressure.
As for the ticking. Blame Jeep - they designed a poor engine that requires too much tlc to keep it from ticking. The Hydraulic lifters are not adjustable, but they are very easy to swap out. At $4 each, changing out all of them is cheap. All you need to do is have the right know how.
For the record, many people tell you to buy a specific Hydraulic Valve lifter remover - which can run you anywhere from $20 - $40. In reality, the engine is designed in such a way that you can actually use a telescoping magnet down the push rod hole and bring the lifter out without using a special tool.
I should caution however, changing out the lifters means things won't mesh the same as the originals as far as wear patterns etc go on the camshaft. Should you change just the lifters, you may actually be setting yourself up for more issues too - depending on the severity of the wear on the ones you pulled out. If possible - use a micrometer to verify how close the originals are versus the new ones before you swap. Tedious yes, but could save you a headache too.
Sunday, July 6th, 2008 AT 5:11 PM