That's one thing I forgot to mention... last winter I had a lifter that was "unhappy" in the mornings. Once the engine warmed up it would quiet down, but the first minute or two was pretty noisy.

I put some Marvel Mystery Oil in for about 200 miles before an oil change, seemed to help a little bit, another 4000 miles and another oil change and I haven't heard the lifter in a while. Not sure if it's because of the warmer weather or if I got the sticky lifter to be unsticky.

The word "sticky" is a misnomer... As long as a cam lobe is pushing the up and a spring is pushing them down thay cannot stick! If is is quiet now the problem was a bit of GUNK in the lifter valve..
Sometimes wear causes one or more lifters to make a continous clicking sound. In the case of a jeep engine the cure is to purchase a slightly LONGER push rod for that lifter. YES mopar makes these longer push rods just for that purpose.
Those lifters that make startup noise and then shutup are BLEEDING off the oil when the engine is not running.. not to worry about them.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Big Jim - I know you've been around the block a few times (I see your expertise in many threads) but I have to disagree with you here, hopefully gently and respectfully. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

A "sticking lifter" is a hydraulic lifter that is not freely compressing and extending. Rather it has compressed the internal spring, but either the lifter is "gunked" or has a burr or other damage that prevents the oil pressure and spring from "re-extending" it. Since the lifter/pushrod is now slightly too short, it sounds like "ticking" when cold. Frequently these lifters will "unstick" once the engine warms up, either because the metal-to-metal clearance has increased so it can slide again or because the sludge that was sticky has become less viscous.

Now that I've attacked you, here's the caveat: I've personally experienced this phenomena in pushrod v8 engines (specifically Ford 289s and 302s) but I haven't been inside my 2.5 I-4, so I don't really know what the valvetrain looks like, where the lifters are, and if they're hydraulic or mechanical!

So, maybe this information is meaningful to these engines, maybe not! <img src="/forums/images/graemlins/cheers.gif" alt="" /> I just had to defend myself! <img src="/forums/images/graemlins/nana.gif" alt="" />

read my post again.. lifters and valves cannot "stick" They can break...they can have problems but they cannot "stick"
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

I re-read your post several times. I'm not saying that lifters stick to the cam; obviously this can't happen if the engine is turning.

My point is that hydraulic lifters themselves are compressible, with metal sliding against metal. Inside of this cylindrical assembly is a spring, as well as an oil passage. This compressibility helps the valve train to absorb some of the mechanical shock and allows longer life; this is the advantage of hydraulic lifters. When lifters get "sticky" the two pieces of the lifter (that normally slide freely) exhibit increased friction, whether due to metal-on-metal wear or sludge or dirt deposits or something else. After the lifter is compressed by the cam lobe, a sticky lifter will maintain its compressed size rather than rebounding to its "full" length. This creates a slack in the system, resulting in a very characteristic "ticking" sound.

A semi-related problem is when high revving engines create too much oil pressure and a lifter "pumps up", preventing the valve from fully closing even when the lifter is on the base-circle of the cam lobe.

If you tell me that my 2.5L I-4 doesn't have hydraulic lifters, then I will believe that the "ticking" that I've been experiencing is not due to a sticky lifter. However, after you questioned me I was forced to query my Haynes manual (ugh, wish I had a Jeep FSM) to ensure that this is in fact a hydraulic lifter, OHV engine -- which it is. If you have your Haynes manual for Wranglers 1987 - 2000 (which is in my lap right now) please see section 2A-9, paragraph 2.

If I missed something or you don't understand the point I'm making, please respond, but please reply with more than "reread my post".

Thank you.

Greggy there is no point in argueing just for the sake of it! We do not disagree on anything except the ONE WORD. It is pretty obvious that the lifter has cleaned itself out and now is working.
Again: Lifters that "speak" on startup have leaked down during their off time. Upon receiving oil pressure again if they shutup they will preform as required.
PUMP UP from high pressure or rpm is rare indeed. Although a possibility under extreme conditions it is rarely seen and never by me.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Ok.
Peace.
As long as you agree that I'm right. <img src="/forums/images/graemlins/nana.gif" alt="" />

I'M KIDDING I'M KIDDING!
<img src="/forums/images/graemlins/cheers.gif" alt="" />