Lifter Tick

[D189379]

I've recently been looking into picking up an older Jeep YJ as a second vehicle. I found one that I really like, but it has a noisy lifter. I've done some research, and this seems to be very common problem with these vehicles.
This has made me a little curious as to what a lifter actually does in the engine, and what makes one lifter noisy and another one not. I've got a basic understanding of how engines work. Ie: camshaft, crankshaft, timing belts, pistons, valves, etc. I don't know where the lifter fits in though. Anyone feel like dumbing this down for me?
Now to remedy this, I've heard suggestions like: live with it; put some thicker oil in it; replace all the lifters; replace the lifters and the camshaft; and a couple others. Is replacing lifters a big job? Is it expensive to get done? Is it even necessary? Should I find another vehicle?
I definitely want this vehicle to last for 4 or 5 years. Is this a sign of a badly maintained or abused vehicle?
Thanks for any input you people may have.

Sorry, it's a 91 2.5 liter if that helps.

 

[D189379]

Anyone? I feel so unloved.

 

[HerkyJim]

I assume that it is a hydraulic lifter. These things have very precision parts. Sticky lifter may cause a regular "tick". Over time it may cause problems. May be sticky due to varnish formation. Maybe indication of less-than-regular oil changes or poor quality oil or several other things. Maybe could be "fixed" by auto rx or mmoil or CD2.
My old mopar 318 v8 has one lifter that sticks ocassionally, especially when cold. Often simply shutting down and restarting will cause the tick to disappear. I'm almost tempted to try auto rx. Tried CD2 and that didn't help. I just live with it for now. The fix is an afternoons work to replace the culprit lifter and I'm too lazy.

 

[eljefino]

In a hydraulic lifter You've got a "piston" and "bore" (bucket) that fit tightly together. At the bottom of the bore is a check valve that lets oil in but not out. With proper oil pressure the piston will expand very slightly over time.

A lifter sits between the cam and pushrod or pushrod and rocker arm or cam and valve... anyway between two things that eventually wear and get more space in them. Before hydraulic lifters were invented you had to take the valve cover off and tighten stuff every 15k miles, or every oil change with aircooled VWs.

Failure points include if that check valve goes bad, then all the oil bleeds out when the car is shut down. Or if that valve is too good you've got factory oil baking in the lifters for 100k miles and turning to sludge.

If one gets stuck you've got a tiny clearance between your pushrod and rocker arm and it'll make noise, sometimes only until the parts heat up and expand. So it'll be like returning to the old days of solid lifters.

Replacing lifters on a Saturn SOHC (my only experience) takes only about an hour! You can also dismantle your present lifter and attempt to clean it.

 

[Matt_S]

FWIW, I'd say keep looking. Personally, I'd rather not ever have to tear into a car's engine and wouldn't buy one that I suspect would need such work. That's my opinion, of course, but I think you'd be much better off trying to find a Jeep without any discernable engine problems.