I have a 98 jeep xj with an AW4. I believe it has made this noise since I've owned it from 150k, has 169k or so now. I changed out the cracked exhaust manifold. That made the engine a little more quiet. I also tightened up the flex plate to torque converter bolts about as tight as I could possibly get them yet the noise is still there. Seems to be there hot or cold. It seems to go away under load and return at idle. I made a video because I know how vague it can sound when describing engine noises.

http://www.youtube.com/watch?v=Q7jLT...ature=youtu.be

 

46 views and no one has a guess?

 

Well, our 4.0's are noisy engines. Both of the XJ's that I have had made noise. How does it run? Any problems? If it runs good, just ignore it unless it gets worse. Lifter tick is very common. I have heard about piston slap or something like that but have never heard it.

 

All I heard was a little lifter noise and louder exhaust manifold noise.

 

if you hold the brake and put it in gear.. does the sound stop?

 

Runs great just like it always has. So each 4.0 to their own pretty much? some are noisier than others and such?

 

So nothing really to be concerned about?

 

No I don't think so.. does it anytime it idles.

 

Here is a news flash: engines make noise when they're running. Some make more noise than others, but a 4.0 will make noise for 500k miles when others won't.

 

What kind of oil and filter are you running?

 

Mine makes the same noise. That slight knock.... You have to hear past all that ticking and valve noise to hear it.... It's been doing it ever since I've owned it, i haven't had any problems and don't think I will. They are loud engines.

 

Runs like a champ. Don't even stress it. If it gets louder change your exhaust manifold and or collector gasket. Also check for cracks in header and what not.

 

This is mine.

 

I put "Cherokee knock" into U-Tube search and found ME, (11 down)>>
Not identical, but similar to yours. It's been doing that for well over 10 years. It's part of the reason the previous owner sold it to me in 02. Please use a Wix filter. or napa Gold, (same thing). Not Fram, the "Orange Can Of Death"

 

Where you been Flintstone? Miss your input.