I understand. But being concerned about a clatter, you never said whether you looked under the oil cap like several have suggested to see if you have flow under the valve cover.

Simple and easy, 1 minute tops.

Pulling plug wires, one at a time? Another easy task.

 

my 01 xj does this same thing. it too had the infamous 0331 head crack, which I caught very early. so I am confident its nothing to do with that. I put an odessa head back on it.

I have tried various oils, filters too. I even used Marvel mystery oil and nothing helped...

Currently running rotella t6 full sythetic, with a wix filter... but i tried mobile 1....royal purple, redline... all the same..

now, I did tighten the flex plate bolts too, so thats eliminated...


the only two things I can think, is rod or main knock, or and this is what I am leaning towards. is a hairline fracture in the flexplate where it bolts up to the crank... to check this one would need to seperate the trans from the engine. which is a pain...

also to note, I have used a stethoscope to check for noise, and this noise at least for mine is pin pointed to the rear main/flexplate..

here is my video.

 

also to note, dont let the cold vs warm noise make you think its internal.

the flex plate is right behind the engine and does get hot and cold. when its cold the metal is shrunk, and allows the flex plate crack to clatter, when it warms the metal will expand and make it seem as if its gone.

go to google and type jeep xj flexplate crack.. you will find various pictures of hairline cracks around the flexplate holes where it bolts to the crank. sometimes they fully brake, other times they hairline crack. flexplate is like 104 bucks for a mopar one... I am not saying this is 100% the case, but after about 3 months of diagnosing the characteristics of this noise from my personal xj, i firmly believe this is the issue.

the picture below is a cracked flexplate. the oil from a leaky rear main will leak through and cause the streaking affect. problem is, this is hard to see unless you slide the trans back, and unbolt the torque converter. because this is the side that is against the torque converter.

basically its one of those jobs where you need a camera, or your just going to have to split the trans from the engine, and hope like hell this is what it is.. Me, Im going to drive the hell out of mine untill the motor craps out, or the flex plate bites the dust... that way the ol lady cant gripe when I drop either a 4bt or a golen 4.6 in it. lol

 

You said the mechanic replaced the cam & lifters...have you looked at the old one? Coolant from a cracked head pours DIRECTLY down the lifter bores and the cam lobes. A worn lifter bore/bores of only .001 will make an engine clatter.
Also on future videos do not record noises under oil pan. As an old man I can tell you that most of us old timers can diagnose a knock with out crawling under the engine. There is too much going on inside the oil pan and it acts like a drum picking up the combustion noises.
Rod knock does not go away when warmed up....it gets louder. Rod knock can be heard from the drivers seat around 50 mph under light load and when you lift off of the throttle.
Valve noise will get less and less loud as rpm increases.
Piston pin noise will make a double knock when you blip the throttle.
I cannot tell from a video I would have to see,feel and drive your machine But if you work with me we might can rule a few things out.

 

Yes I did that and there is oil sloshing around up there.

 

Can you at least look under you oil cap? Any yellow snot stuff?

 

Are you still losing coolant?

 

No, I have kept a close eye on the coolant reservoir and its not losing anything. Oil looked clean an oil cap is clean.

I am leaving with a 4x4 shop on the 17th (fixing my lift and installing new motor and trans mounts) while I leave on vacation, guys says he is an ASE certified master mechanic and should be able to diagnose it and let me know if anything should be done. I know I haven't been the most helpful guy thanks to my limited mechanical skills, but believe me I appreciate all of the opinions and now at least feel comfortable discussing options with the mechanic.

 

You said the mechanic replaced the cam & lifters...have you looked at the old one? - No, was done by PO

Coolant from a cracked head pours DIRECTLY down the lifter bores and the cam lobes. A worn lifter bore/bores of only .001 will make an engine clatter.
Also on future videos do not record noises under oil pan. As an old man I can tell you that most of us old timers can diagnose a knock with out crawling under the engine. - its very hard to hear anything out of the ordinary unless I am recording from underneath

Rod knock does not go away when warmed up....it gets louder. Rod knock can be heard from the drivers seat around 50 mph under light load and when you lift off of the throttle. - this does not happen to me

Valve noise will get less and less loud as rpm increases. - this does happen to me but I cannot be 100% sure that the noise is going away or just being covered up with the normal engine noise under load

Piston pin noise will make a double knock when you blip the throttle. - not 100% sure but I dont think this is happening

 

That sounds very similar to mine, if that is it is there an issue with leaving it like that?

 

Using a long wooden rod like a cut-off broom handle listen to passenger side of block. With one end stuck against your ear probe the other end along the head gasket seam and tell us where the noise is the loudest. If you cannot pin point the noise repeat procedure with a long screwdriver. The wooden rod or dowel will attenuate stray noises and help you find the exact spot.

 

I borrowed a mechanics tool and the attached pic is where I can hear it the loudest. It didnt sound loud at all along where you told me to check nor did one area along the head gasket sound louder than another, all were pretty quiet.

 

Hard to record inside the oil cap but here it is, hard to tell from the video but there is no noise coming from inside the oil cap:

 

see that is exactly where my noise is the loadest too. basically the very back of the oil pan, but up inside the flex plate inspection cover. this is why I firmly believe that it is a hairline fracture in the flex plate. Like I said if it is indeed the flexplate cracked, which I am like 90% sure on mine... the part is cheap...104 bucks through mopar. the problem is the amount of work involved in seperating the trans from the engine, just to replace it. local shop wont touch it for less that 600 buck labor. and for an average guy without a lift, its a pain. can be done... im just not to keen on laying on my back in the gravel for hours. maybe this summer I will do it.

btw, a cracked flexplate is kinda bad... cause if it goes... it can throw pieces through the bell housing... which would cost more. but, if you keep an ear on it, and it doesnt change right away, or get worse ima keep driving it. not recommended though.. just a lot of work to change something that your not 100% about.

 

btw, another cheap way to check for noised is a piece of fuel hose, cut to about 2 to 3 foot. put one end in your ear and the other to probe for noises.