I have a 1999 Jeep Cherokee XJ with 4.0 it has 175000 miles on it. I drove it Sat it ran and sounded fine just like it always dose. I parked it in the drive way. I came out Sun to go somewhere and it had a ticking/clicking noise. The noise sound's like it is coming from the top end around # 5 or 6. This is what i have done so far. I pulled all the pulg wires one at a time wile engine was running the nosie did not change. I pulled the valve cover and looked at all the rockers and push tubes everything looked good as far as I could tell. I did not pay very close attention to the valve springs. I started the engine up with the valve cover off and did not see anything looking odd. I did not leave the engine running long because oil was squiritng about 6 to 8 in above the rockers so I have good oil PSI. I changed the oil and the filter and I did not see anything in the oil or in the oil filter. The oil change did not help the noise at all. I dont want to drive the Jeep untill I find out what Her illness is. I am looking for anyone that could help me with what this noise is and what I need to do to fix it. I have added a link to Youtube video so you can hear it for yourself. Thanks for any input.

 

Could it be an exhaust leak at the manifold? Can't watch the video though...it's set to private.

 

No it dont sound like an exhaust leak. Sorry i fixed the video.

 

Flexplate bolts tight?
I have a feeling if you pull the oil pan you'll find a chunk of piston skirt. Probably #6. That noise is fairly unmistakable.

 

Could possibly be a problem with a lifter. Aka "lifter tick"

 

Do you have a mechanic's stethoscope? They can be real helpful in pinpointing a more exact location and shutting out distracting sounds. That or a long screwdriver's handle pressed to the ear while probing around with the metal tip.

For a while I thought I had an intermittent lifter ticking in #5 or #6 position but it turned out to be that vacuum solenoid on top of the evap canister. Drove me nuts trying to isolate it until I put the stethoscope to it.

Your audio definitely sounds like the noise is mechanical inside the engine, though.