check the camshaft synchronize. thats what ticks on mine.

 

Ill bet you a 12 pack its your timing chain. They start getting stretched and slap against the timing chain cover. I know from experience lol. Theres a way to check you can search it on here. Good luck.

 

I just spent the last couple nights doing the intake/exhaust manifold gasket. If it gets any louder I'll look into checking the timing chain. Seems like a pain in the arss though.

 

It's not terrible. You'll thank yourself later if you just pull the front end off. If you have the extra money I'd swap the water pump to. I think O'Reillys was only 40 bucks.

 

Howdy neighbor! You're just down the hwy from me, I'm over in Wis. Rapids.
Mine makes nearly the same noise as in the video- when cold. Once it warms to operating temp it stops. I'm nearly certain mine is piston slap. It's been that way for the last 150K miles or so, lol. I just baby it until it warms up and forget about it.
Does yours do it all the time or only when it's cold?

 

Mine does it all the time up to a certain RPM. Tends up be louder when cold though.

 

Hi new to the forum! I have a 2001 XJ that has this exact same problem. Looking forward seeing how it works out for you so I may fix this myself.

 

Based off everything I've checked, I've got it narrowed down to three possible things (I think): timing chain is loose and slapping cover, lifter is sticking (which I just put in Mystery oil last night so well see if that works), or mild piston slap.

 

Are you sure it's not the standard valvetrain noise that comes standard with almost every 4.0 L6 with more than 100k miles?

 

Yes, I've had a couple other Jeeps with 4.0s and this is the first one to make this noise.

 

Can you post a recording of the noise yours is making?

 

M7 94 xj 4.0 auto is making the same noise, like a retarded ticking from the pulley area. I did the long screwdriver trick and found nothing in the engine both top and bottom end nor the tranny especially around the flexplate area. I did find this noise in the water pump though. I have a brand new pump and run just under 210 all day long.

I was thinking of getting water wetter since it worked great in other vehicles ive had unless I find a cooling system lubricant. This is my first Jeep. Finally ditched the bowtie. My vehicle was sold new in NE illinois and has been here the last 20 years bone stock.