Soooo there’s a thing happening to me lol, I just bought a 2001 XJ and all was well. 180k on the original motor so young and just getting broke in, oil was a little dark and was doing what everyone (I would assume) would do when you get a new to you car and did my own tune up/ fluid change. After changing the oil/filter and moving to full synthetic (no idea what the prior owner had run) I went with what was on sale because I was going to run 5 quarts and then a quart of MMO to help clean up any build up and change the oil again in about 1000 to Rotella T5. Right before the oil change I also ran a can of sea foam through the throttle body for good measure and not a puff of smoke came out! (Maybe I did it wrong?)

with the fresh oil I began my first trip to work with no issues and returned no problems, checked the oil again to make sure I was in the safe zone just in case and checked for any leaks (oil filter had a small dot nothing unacceptable). Second day I went out and BOOM tick/knock like shown in the video, I pushed on as I was assuming just lifters and arrived at work to pop the hood and the tick/knock was gone, left from work and on start up the same issue, arrived home and it was gone again. This is my current dilemma and same issue for the past two days, it does not seem to be getting any worse so I’m at a lose and would like any advise before I break into this bad boy and go down a car.

thanks in advance for any input.

EDIT- I don’t think the attachments are working for me, here’s a link:

 

I also forgot to note that my oil pressure is holding strong however after my trip to work this morning I did note a small fluctuation at idle in the pressure.

 

So is the noise still come and go? Have you looked inside the valve cover with a light to see if there is excessive sludge build up? Just because your gauge is showing oil pressure doesn't mean your getting oil flow. What does the coolant look like? Are you familiar with the 0331 head issues on the '00-'01 XJ's? Don't freak yet though. lol

https://www.cherokeeforum.com/how-to...rmation-398176

 

Im trying not too lol, Yes the noise is still coming and going but its not like some where after it reaches normal temp it just goes away. If I stay in town it will continue until I drive the highway a few miles and then it will disappear, I can come back 5 minutes later with the engine still warm and turn her on to find the same tick/knock. I have not taken the valve cover off completely but I did inspect what can be seen from the fill cap and there is no build up and rockers in sight have oil coming up. coolant is clean and at level with since it was bought. I have heard of the lovely 0331 head issues but I am not seeing any signs of coolant so I was not leaning towards that as my issue

 

Is there good oil flow to the top end when the noise is happening? Maybe it's an intermittent oil flow loss issue. I'd hook up a mechanical oil pressure gauge to monitor and verify the pressure. Maybe rent one at a local parts store,borrow one, or...…….
https://www.harborfreight.com/engine...kit-62621.html

Just because your not seeing signs of coolant doesn't mean there's no 0331 issue. A test of the oil and/or exhaust fumes in the coolant would tell more. BUT I haven't heard of anyone describing symptoms like your having being associated with the head failure.

 

It's pretty common for the 4.0 lifters to tick like that until it warms up. Mine has done that ever since I have owned it.

 

Thank you for the advice I will start by actually tearing the valve cover off and checking that all rods are pushing oil to the rockers and then renting a test kit to see where we truly are at! thanks again

 

I do know they commonly have lifter tick and in the video with the slow-mo part you can hear both and even distinguish them from each other so I believe this one in more then just my lifters at work, though I could be wrong haha I am not an expert but I have owned 3 XJs 96/98 and now this one and even when I first got it before the oil change and seafoam the lifters were not at the audible of a level.

 

Next time it does it on starting, shut it off and wait 10 seconds to restart. Does the noise go away?

 

Tried it after work, it does go away for about 5-10 seconds and then comes right back where it was...

 

Take a peek through the oil filler hole and assess the sludge buildup.

 

I did do this to see if there was anything and honestly it looks as clean as I have ever seen one (with the small amount you can see through the filler cap), its not milky or anything odd....no anti-freeze from the what oil is sitting in the rocker either.

 

There’s a slight possibility it could the oil. One of the 98’s I drive I used Quaker state once when Walmart didn’t have rotella and I didn’t even wait a week before I changed it again because it sounded horrible. It always makes a little noise but it was much worse. Then an 01 my wife had we got the oil changed at a shop one time and they used 5-30 and it started getting noisy. It never made a sound before that. Never made a sound again after I changed it either. A third experience with a WJ that also had the 4.0, I didn’t know about using Rotella at that point in time and I always went with whatever was on sale and some oils caused the motor to make noise and some didn’t. Obviously this isn’t always the case but just my experience and still a possibility.