Pic: worn Jeep 4.0 rocker pivot fulcrum
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Great, well written thread! The suspense is killing me! 

I almost always start all the bolts on anything before tightening one. (maybe I didn't read all of it)


I almost always start all the bolts on anything before tightening one. (maybe I didn't read all of it)
She's ALIVE!!!
Took about 3 min after starting to see the oil come up the lifters...
Then, it filled the cups nicely:

Look at that chocolate milk filling the cups: yummy! (looks like I better change that oil pretty quick)....
Then, as it warmed up, the cups emptied again (not completely):

You can see the oil squirted up the sides of the cardboard after I gave it a little throttle. Seems like a good sign.
Anything to do before I put the rest back together (besides change the oil)?
Took about 3 min after starting to see the oil come up the lifters...
Then, it filled the cups nicely:

Look at that chocolate milk filling the cups: yummy! (looks like I better change that oil pretty quick)....
Then, as it warmed up, the cups emptied again (not completely):

You can see the oil squirted up the sides of the cardboard after I gave it a little throttle. Seems like a good sign.
Anything to do before I put the rest back together (besides change the oil)?
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
She's ALIVE!!!
Took about 3 min after starting to see the oil come up the lifters...
Then, it filled the cups nicely:

Look at that chocolate milk filling the cups: yummy! (looks like I better change that oil pretty quick)....
Then, as it warmed up, the cups emptied again (not completely):

You can see the oil squirted up the sides of the cardboard after I gave it a little throttle. Seems like a good sign.
Anything to do before I put the rest back together (besides change the oil)?
Took about 3 min after starting to see the oil come up the lifters...
Then, it filled the cups nicely:

Look at that chocolate milk filling the cups: yummy! (looks like I better change that oil pretty quick)....
Then, as it warmed up, the cups emptied again (not completely):

You can see the oil squirted up the sides of the cardboard after I gave it a little throttle. Seems like a good sign.
Anything to do before I put the rest back together (besides change the oil)?
When you change your oil run it for a couple of miles then drain it. Add 5 quarts of 10W-30 and a quart of MMO, and a new filter.
Keep an eye on the internals through the oil fill port in the VC to see if the oil gets milky again.
I think the Lucas assembly snot was helping to hold a seal in the gaps/grooves between the pivots and rockers. When temp came up, that sticky lube melted away, allowing the oil to flow out of the bottom of the rocker at a faster rate... that's one theory anyways.... Maybe I should go back, and swap around the rockers, so that the gooves criss-cross with the pivot grooves instead of mate with them... The AutoZone replacement rocker I saw the other day has NO GROOVES.
The reason the oil is milky: I loosened my head bolts a few days BEFORE I drained the radiator. After sitting for weeks, I then drained about 6 quarts out of the oil pan (figuring that the coolant would have sunk to the bottom), then refilled about 2 quarts of oil to bring it back to the normal range on the dip-stick. Guess that didn't work so good.
Additional info: The first photo is at about 5min after first start-up, after I reved it a bit, then let it settle for about 30 seconds. Oil pressure was reading about 40 at that time. The 2cd photo is at 650RPM, about 205 deg on the thermostat gauge (I dont think the mechanical thermostat ever opened), and about 26 PSI on the oil gauge. Maybe I should have let it idle for 1/2 hour, but I did not like the color of that oil. Draining it right now. Maybe I'll put in new, and repeat the test?
Finally: MMO = marvel mystery?; I have Rotella T 15W-40 on hand, could I use one quart of that (or more) instead of MMO? Thanks again.
The reason the oil is milky: I loosened my head bolts a few days BEFORE I drained the radiator. After sitting for weeks, I then drained about 6 quarts out of the oil pan (figuring that the coolant would have sunk to the bottom), then refilled about 2 quarts of oil to bring it back to the normal range on the dip-stick. Guess that didn't work so good.
Additional info: The first photo is at about 5min after first start-up, after I reved it a bit, then let it settle for about 30 seconds. Oil pressure was reading about 40 at that time. The 2cd photo is at 650RPM, about 205 deg on the thermostat gauge (I dont think the mechanical thermostat ever opened), and about 26 PSI on the oil gauge. Maybe I should have let it idle for 1/2 hour, but I did not like the color of that oil. Draining it right now. Maybe I'll put in new, and repeat the test?
Finally: MMO = marvel mystery?; I have Rotella T 15W-40 on hand, could I use one quart of that (or more) instead of MMO? Thanks again.
Last edited by JohnEP; Mar 9, 2013 at 02:48 PM.
When I was removing the old head, I forgot to drain the radiator BEFORE I loosened the old head bolts. This put coolant into the piston(s) and elsewhere, which slowly drained down over the weeks I've been working on it. Right before starting it today, I tried to drain that coolant out of the bottom of my oil pan, while saving most of the 'good oil' I supposed was floating on top. Sounded good at the time....
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
When I was removing the old head, I forgot to drain the radiator BEFORE I loosened the old head bolts. This put coolant into the piston(s) and elsewhere, which slowly drained down over the weeks I've been working on it. Right before starting it today, I tried to drain that coolant out of the bottom of my oil pan, while saving most of the 'good oil' I supposed was floating on top. Sounded good at the time....
What Cruiser 54 said is cool, but I'm not a big fan of 15W-40 oil so it's your choice of final oil that you use. The FSM recommends 5W-30 for extreme cold and 10W-30 for a wide range of outside air temps. The MMO is to assist in loosening up your lifters and oil passages.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Don't play grab a$$ with the oil. Drain that crap out of your oil pan, and chit can the filter, then fill it with some cheap 10W-30 oil and run it a bit, then drain that crap out and replensish it with fresh oil and a new filter (not a Fram).
What Cruiser 54 said is cool, but I'm not a big fan of 15W-40 oil so it's your choice of final oil that you use. The FSM recommends 5W-30 for extreme cold and 10W-30 for a wide range of outside air temps. The MMO is to assist in loosening up your lifters and oil passages.
What Cruiser 54 said is cool, but I'm not a big fan of 15W-40 oil so it's your choice of final oil that you use. The FSM recommends 5W-30 for extreme cold and 10W-30 for a wide range of outside air temps. The MMO is to assist in loosening up your lifters and oil passages.
The JY engine I put in my wife's XJ was a little sludgy and the Rotella and MMO cleaned it up rather quickly.
Seasoned Member
Joined: Feb 2013
Posts: 342
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From: Southern California
Year: 1989
Model: Cherokee
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
then fill it with some cheap 10W-30 oil and run it a bit, then drain that crap out and replensish it with fresh oil and a new filter (not a Fram).
What Cruiser 54 said is cool, but I'm not a big fan of 15W-40 oil so it's your choice of final oil that you use. The FSM recommends 5W-30 for extreme cold and 10W-30 for a wide range of outside air temps. The MMO is to assist in loosening up your lifters and oil passages.
What Cruiser 54 said is cool, but I'm not a big fan of 15W-40 oil so it's your choice of final oil that you use. The FSM recommends 5W-30 for extreme cold and 10W-30 for a wide range of outside air temps. The MMO is to assist in loosening up your lifters and oil passages.
During disassembly, there was very little sludge on my torn-up rockers. Even so, I wish I had not done the "kerosene wash": this probably tore things up worse than the benefit of the cleaning. BUT, it DID seem to clean sludge well: based upon the cleanliness of my old rockers, I'm not worried about sludge anywhere... Of course, there were many other things I was also "not worried about" during this project (twisting bridges, saving oil, etc.), that I now do.
To get back on track: I plan to refill my case with fresh oil, and re-try the cardboard test tomarrow to see how my rockers fill. I plan to use what I have on hand: 3 quarts 5W-30, and 3 quarts 10w-30. I cannot drive the Jeep this way (cables disconnected), so how, exactly, should I do this test?
I need to know: what exact temp and RPM do I need to see the cups "stay full", and also gently flip oil onto the valve springs? If this test requires a certain weight of oil, then I will make that happen (if the mix I have on hand is really not right for the test).
Thanks again.
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Done tonight.
When I first discovered coolant in my oil (before I knew anything about 2000 head-cracks), I immediately drained out ?9? quarts of antifreeze-oil, and replaced the oil filter. Based on questionable advice, I then filled it with 4 quarts 5w-30 and 2 quarts kerosene. Ran it for 5 min, idle only, with 2 short revs. Drained that, then, leaving the 'new' oil filter still in place, filled it with 5 quarts of 5w-30. Then I did my oil pressure test: settled at 19psi after spirited driving. Upon this result, I decided to gamble with the replacing the head instead of the engine.
During disassembly, there was very little sludge on my torn-up rockers. Even so, I wish I had not done the "kerosene wash": this probably tore things up worse than the benefit of the cleaning. BUT, it DID seem to clean sludge well: based upon the cleanliness of my old rockers, I'm not worried about sludge anywhere... Of course, there were many other things I was also "not worried about" during this project (twisting bridges, saving oil, etc.), that I now do.
To get back on track: I plan to refill my case with fresh oil, and re-try the cardboard test tomarrow to see how my rockers fill. I plan to use what I have on hand: 3 quarts 5W-30, and 3 quarts 10w-30. I cannot drive the Jeep this way (cables disconnected), so how, exactly, should I do this test?
I need to know: what exact temp and RPM do I need to see the cups "stay full", and also gently flip oil onto the valve springs? If this test requires a certain weight of oil, then I will make that happen (if the mix I have on hand is really not right for the test).
Thanks again.
When I first discovered coolant in my oil (before I knew anything about 2000 head-cracks), I immediately drained out ?9? quarts of antifreeze-oil, and replaced the oil filter. Based on questionable advice, I then filled it with 4 quarts 5w-30 and 2 quarts kerosene. Ran it for 5 min, idle only, with 2 short revs. Drained that, then, leaving the 'new' oil filter still in place, filled it with 5 quarts of 5w-30. Then I did my oil pressure test: settled at 19psi after spirited driving. Upon this result, I decided to gamble with the replacing the head instead of the engine.
During disassembly, there was very little sludge on my torn-up rockers. Even so, I wish I had not done the "kerosene wash": this probably tore things up worse than the benefit of the cleaning. BUT, it DID seem to clean sludge well: based upon the cleanliness of my old rockers, I'm not worried about sludge anywhere... Of course, there were many other things I was also "not worried about" during this project (twisting bridges, saving oil, etc.), that I now do.
To get back on track: I plan to refill my case with fresh oil, and re-try the cardboard test tomarrow to see how my rockers fill. I plan to use what I have on hand: 3 quarts 5W-30, and 3 quarts 10w-30. I cannot drive the Jeep this way (cables disconnected), so how, exactly, should I do this test?
I need to know: what exact temp and RPM do I need to see the cups "stay full", and also gently flip oil onto the valve springs? If this test requires a certain weight of oil, then I will make that happen (if the mix I have on hand is really not right for the test).
Thanks again.
What do you mean "I cannot drive the Jeep this way (cables disconnected)"? You don't need to drive the Heep to do the oil flow check.
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
The mix of 3 quarts 5W-30, and 3 quarts 10w-30 looks okay for what you plan on doing. As far as what RPM to check oil flow, the normal cruise RPM that you see should be adequate to check oil flow; I'd say around 1500-2000 RPM should do it. At idle RPM you won't see alot of flow.
What do you mean "I cannot drive the Jeep this way (cables disconnected)"? You don't need to drive the Heep to do the oil flow check.
What do you mean "I cannot drive the Jeep this way (cables disconnected)"? You don't need to drive the Heep to do the oil flow check.
After you've done this 'flow check' drain that oil out and fill it up with your Rotella and some MMO, and a new oil filter.
Good luck mate.
Seasoned Member
Joined: Feb 2013
Posts: 342
Likes: 0
From: Southern California
Year: 1989
Model: Cherokee
Engine: 4.0
awesome thanks! I have been researching your renix tips, very helpful. but my multimeter won't measure low enough on ACV for the CPS... just checking it to catch it before its a problem. can't wait to take this thing out!


