take a stab at diagnosing "tick"

[TiGuy]

Just my luck. I found this board after beginning to collect parts years ago for a "sometime in the future, during my SPARE time" stroker project for my 2000 TJ with over 90,000 miles on it. I have heard about piston slap from the 4.0 and I want to confirm or rule out if thats what I am getting from my rig now (just before going to EJS of course).

First of all, I have not found any foaming in the oil but I have not had any tests run to confirm/deny any traces of contaminates/coolant. I do use some coolant but I blow it off to the fact I have no overflow resevoir.

There is no ticking noise while the engine is warming up, but it is present at running temp and can only be heard at idle.

This is a trail rig, Its no daily driver but the noise hasen't gotten any worse in the last few months.

Now I learn from this board about the 0331 head problems and I could possibly have one of the crack prone units.

Whats your opinion?

[John]

You might have a lifter not pumping up properly, The oil is thicker until it warms up then at idle you hear the lifter tic, they pump up better at rpm (don't have time to bleed down) noise seems to disappear. Then there is exhaust leaks, cracked pistons, etc. Check the easy stuff first. Look around for a shop that can analize your exhaust. They can check for it by instrument. Of course if you start making new cloud formations, you wouldn't need the test. Check your lifters, manifolds and header first.
John

[SilverXJ]

I had a similar tick on my original 4.0L, not present when cold, there when hot, after it was hydro locked. Eventually a piston failed, so it was probably a bent rod. Is it coming from the top or bottom end?

[SilverXJ]

You might have a lifter not pumping up properly, The oil is thicker until it warms up then at idle you hear the lifter tic, they pump up better at rpm (don't have time to bleed down) noise seems to disappear.

If it was a lifter not pumping up, wouldn't there be a racket when cold?

[TiGuy]

If I had to guess, I'de say it is coming from the top end. It's more noticable from inside the jeep than it is from the outside.

[John]

You might have a lifter not pumping up properly, The oil is thicker until it warms up then at idle you hear the lifter tic, they pump up better at rpm (don't have time to bleed down) noise seems to disappear.

If it was a lifter not pumping up, wouldn't there be a racket when cold?

If the lifter was not pumping up, yes. but Not properly pumping up, give it a increase in tolerances, wear, and some of them just don't behave properly.
John

[John]

Dirt, gum internally. someting keeping the check mechanism from sealing completly can sometimes do this. Check the easy things first, manifold sealing, header for cracks/leaks, might consider a basic engine flush to see if that changes the sound.....
John