Hi all,

I just purchased this XJ, it didn't knock at all when I was checking it out (drove it quite a bit too) and now it decided it was time to knock. So I'm like... GREAT . Anyways, I'm new to vehicles in general - I'm only 19 and this is my second vehicle but I really would like to get in to starting to understand how they work and learning how to do maintenance myself (however, I am mechanically inclined and usually a quick study). So I would really appreciate any tips or clues on this issue; if you wouldn't mind, try to explain things rather clearly as I am pretty new to all of this.

Also I should add - oil pressure sits at just past halfway, when driving hard it will rise to about 3/4 on the dial. Could this mean oil is getting where it needs to go b/c of a clog or something? Perhaps that explains the rise in pressure? Like I said I'm new to this. I can upload a video of that too.. just have to get gas, which I'm lamenting!

It drives great, shifts great, 4 wheel hi and lo work as well as 2 wheel. No loss of power, it's actually quite peppy, even in the hilly Laguna Beach area.

I have read lots of posts and I'm just not sure what this is!

Thank you!

Enjoy in 1080p (Canon EOS 6D w/ 24-105L)

 

Try and listen to where it sounds like its coming from. I had an accessory belt that sounded like that.

 

Also had a wrist pint bearing that sounded like that. also see if it goes away when its warm.

 

It's still there when it's warm, possibly a little less pronounced. Really I noticed that it sounds clearest/most audible over the valve cover. Not sure where the wrist pin bearing is - how can I check/diagnose that?

Thanks

 

Check the torque converter bolts and make sure they're tight. My 4.0 sounds kind of like yours, 211k miles with NO issues.

 

That's a little comforting. I don't have a lot of money to put towards maintaining this vehicle!

I will check those possibly tonight if I can get enough light under it. Thanks!

 

I would suggest crawling under and listening for it to be louder. Does it happen only in specific gears, such as park or neutral? Could be your flexplate bolts loose. Happened to mine recently and I redid them all with red locktite, and it made quite a difference in sound overall, although it was an intense rattling at park and neutral only, and noticeable right at startup.

 

At 30 seconds or so it sounds like rod knock or some valve tap. I think its really hard to diagnose through the video. Does the noise increase in intensity with driving? Does it click faster or is always just a steady tap? It looks like its in great shape though, so I would be surprised if that was it but you never know.

 

The thing has been well looked after. Serviced regularly, the only issue is it has a lot of rust and a few leaks that I need to check out, one of them being the valve cover gasket.

I will take another video right now, trying to be a little more specific about location etc.. be right back!

 

Sounds like good ole piston slap to me. Mines done it since the day I bought it and has 225k on it now, still slappin and still running like a champ

 

Cant hear well through the video but could it be a bad exhaust leak?

 

LOL uploading another video now -- i turned it on and the muffler decided to "spring a leak" or whatever hahah it's falling apart in my hands!! Anyways I'll upload the new video, perhaps it will help. Not too much of a discernable difference underneath or above.

 

If its something inside the engine, you can try pulling the wires off the plugs one a time with the engine running and see if you can isolate the problem. If it stops making the noise or it changes it might be in the cylinder without the spark.

 

Okay here's the second video. Compressed it as 1080p takes forever to process. Audio should be unaffected.

The knocking (although it may seem different on the camera) sounds more pronounced above than below.

Also, my muffler decided to crap out sooo there's that -- literally right as I was making the video. I should rename her from pepper to moneypit.

motoo344 - I will attempt that possibly tomorrow when there's light. I have never really worked on an engine before -- anything to be careful of when doing this?

Video:

 

This is a good idea, definitely need to remember this.