4.0L Lifter Noise

[SkywagonJim]

I have a 2001 TJ, with a 4.0L 6 cylinder that has, as best I can describe, lifter noise, which seems to be coming from either #5 or #6 cylinder. It is the loudest on cold engine start-up, and decreases after the engine warms up through normal driving. The TJ has 176k miles and I have every reason to believe that the engine is original. The engine does not use any oil between my 3,000 mile oil and filter changes.
My question to the experts in this group is this: Is this something that I should be concerned about? Is this likely a precursor to a failure? Is this just normal for an engine having this many miles?

Thanks in advance,
SkywagonJim

 

[JPNinPA]

Yes and no on the concern.
Some actual lifter noise is from oil not making it on top of the head for two main reasons. Oil pump or the oil filter valve. Some filters have a poor valve design allowing all oil to drain back to the pan delaying delivery to the top end. Second cause for concern is the intake/ exhaust bolt on 5 or 6 backs out. If caught early enough there is no damage to the gasket. Otherwise the gasket burns and possibly the intake and exhaust warp.


JPNinPA
Using Jeepz.com app

 

[Bounty__Hunter]

Add a quart of ATF to the oil and see if the noise changes.

If it's loud and changes with RPM it could be a busted piston skirt.

 

[TerryMason]

What does the ATF do? Is that a temporary fix, or does it clean things a bit?

I've owned a bunch of junkers in my time, and when I had a noisy one I would run a really heavy oil, and was pretty liberal with the motor honey / no smoke. It was just a bandaid, but treated the symptoms.

 

[mark sr]

The ATF will clean the lifters [and everything else] I've never run long term with it or anything like it in the oil but it does good just before an oil change. It will only fix a noisy lifter if it's sticking, won't help if it's worn out.