Hi there! I've had this XJ since 2018. It has 150,000 miles. Last year I just completed a full floor pan replacement project on it. The pans were rusted out when I bought it for a song in '18.

Starting to finally get to the fun stuff on this Jeep. But I was wondering if you guys could listen to my engine and let me know if you hear any knocks, ticks, or anything bad? Feel like I'm being paranoid, but also just trying to learn more and figure out what I've got.

Is the "gurzle gurzle gurzle" just valve train/lifter noise, or just a normal sound for this range of 4.0L? I tried to use a professional-level microphone on an iPhone 11, hoping this got some good sound input. I would really appreciate any input!

 

Honestly it sounds pretty normal to me, run some sea foam through the intake and possibly tighten the exhaust manifold.

 

Sounds like a pretty typical 4.0l. May want to check the torque converter bolts and inspect the flywheel for cracks, they are pretty well known for causing some noise. Otherwise its pretty typical.

 

good call, torque converter bolts.. mine were loose and had that rattle.

 

Sounds just like mine, ive had 2 '96s they seemto rattle a bit. First one developed more of a knock, it was the harmonic balancer coning apart and hitting the oil pan. apparently common

 

Sounds very much like you have an exhaust leak there.

Trying to diagnose potential engine noise is virtually impossible when one is present, however that louder knocking noise warrants further investigation.

it may be "nothing", but I would try and find out where its coming from with an engine stethoscope or rod, could be TC bolts, easy to check

Once your XJ is "quiet" you can listen to see whether it has excessive lifter noise, piston slap, pulley bearings etc

My XJ runs pretty friggin quiet after 5yrs, still got a few rattles to fix, new ones develop, may put sound deadener on the floor soon

 

Did you figure this out?

My 96 4.0 made a similar knocking sound and it turned out to be the water pump. It was so worn that the impeller was chewing up the inside of the housing, yet amazingly it didn’t leak a drop.

You could remove the belt and run it for a very short time to see if the sound disappears. That could help determine if it’s internal or external.