The Jeep thing

yoder519

Well-Known Member
Joined
Feb 1, 2010
Location
Abingdon, VA
Well, I bought my wife a stupid clean 2000 Cherokee today power everything etc. Looks like its never been sit in . Got 173k miles on it. I test drove it, ran the crap out of it and everything was good. So I bought it and a killer deal on it. My wife was taking it home and the check guages light came on. I got there, and it was idleing at 2psi oil pressure, when you revved it it went to about 12psi, and when you drove it it was at 12psi. SO I bought a sending unit. Nope. Put a guage on it, read the same as the dash. Made sure it had the right oil filter. yep. SO I figured theres only 3 more things it could be.. pickup screen in the oil pan, oil pump, or bearings. It stated to produce a little peck when you revved it, but not when your driving it. Still runs awesome and tight like it did before. When I test drove it, it held a little more than 40psi the whole time. What do you guys think? I dont think a bearing would go out at once. I think it may have picked up something in the screen. I unbolted the oil pan and realized I got to either unbolt the starter or the exhaust. Im gonna say the starter is the best way to go?
 
Most likely the oil pump or screen. Yes the starter has to come off to drop the pan, the exhaust should be ok but it will be tight. I usually jack the frame up and put it on jack stands to droop the front axle a bit to give me room to work. Put a new rear main seal in while you are in there.
 
yea rear main leaks just a hair to. I bought a new oil pump also Im gonna put it in anyways while im in there. It looked to me like you could either take starter off or the exhaust. BUt it will com eoff with the stater removed?
 
yoder519 said:
yea rear main leaks just a hair to. I bought a new oil pump also Im gonna put it in anyways while im in there. It looked to me like you could either take starter off or the exhaust. BUt it will com eoff with the stater removed?
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Yes, just the starter, I have never had to drop the exhaust on a XJ to drop the pan. Its tight though. I use the Fel-Pro one piece pan gasket and rear main seal. On the 2000 there is a main bearing girdle or truss that has to be removed before the rear main cap can come off. Its a straight forward repair though.
 
well I finally got the pan dropped. Had to flex the axle toward the passenger side to get it out. SO I guess you could say I finally removed the Cherokee from the oil pan. Then I found a clean strainer and a little sludge in the oil pan, but not what I expected. Also, a bunch of fine grains of metal, bout a quarter the size of a grain of sand, and a few bigger chunks bout double the size of a grain of sand. Also, 2 of the nuts on the splash rail was laying in there. So Im gonna go ahead and get a guy from work to put a main bearing in it and rod bearings, put the new oil pump on and see what happens. Gonna pull the valve cover tomoro to see if theres any shavings up there first though.
 
3 of the 4 rod bearing we checked had quite a bit of slack, and so did a main. So Im gonna replace the main and rod bearings. Also, the timing chain is pretty worn, which would explain the brittle metal in the oil pan. So that's getting replaced to. Turned out the motor has been in before, the rod caps was stamped with the cylinder number. The rod bearings some were worn some wasn't. They had 11/08 stamped in them, and they were Clevite bearings. From what ive seen on some Jeep forums, this brand is a bad idea because the bearing doesn't have the oil squirt hole I think its called. Also, the friggin rod bearing caps had about 65ft/lbs of torque on them. I didn't check them with a torque wrench, but it was more than the 30 some pounds Ive seen that's recommended. SO, What is the best brand of bearings that I can get? rod bearings were .020 and mains were .010.
 
ive done many 4.0 rebuilds lately and the stock napa or advanced auto brand works just fine for a factory rebuild. torque them down and let her go. I would suggest going all the way with it if your going to do rods and mains cause all that's left is rings and that's all you mostly need on the 4.0. I bet anything that if you pull the pistons out, you'll find EVERY single oil passage hole on each piston clogged completely as 99% of 4.0s I've torn apart are and you'll see why if you pull out the pistons (the poor jeep design....very very small oiling holes for the pistons on factory) take them out clean out each hole which takes some time and put new premium rings for 110.00 and then you'll know your good for another 100k easily. as to the shavings, I wouldn't be surprised if part of a piston skirt broke off as they are prone to doing that. feel free to call anytime for more detailed help. I work on mostly all Cherokees and Grand Cherokee 4.0 for long time now and this is what I mostly 98% of time see in these when taken apart. Main and Rod bearings are hardly ever a cause for oil pressure or knock....Piston slap and oiling holes are the culprit with an occasional oil pump going out. hope this helps...good luck..John 828-217-0730
 
Thanks John for the info. I wish I had seen this before I put the motor back together last night. The bearings were extremely wore down to the brass. Got everything back together just to see the oil pressure only go up to 12psi at idle and 22psi when your driving it. That's with 10w-30 so as soon as O'Reilly's opens up this morning im gonna go get some 15w-40 Diesel oil and put in it and see what kinda pressure I got. And now im in the market for a 2000+ 4.0L for a Cherokee. Good motor or bad its gonna get rebuilt. You know of any John?
 
yoder519 said:
yea rear main leaks just a hair to. I bought a new oil pump also Im gonna put it in anyways while im in there. It looked to me like you could either take starter off or the exhaust. BUt it will com eoff with the stater removed?
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The rear main on a 4.0L will always leak. If it doesn't then it's out of oil. Also alot of people run 15w-40 rotella in the 4.0L so it should like it.
 
Redneck92 said:
The rear main on a 4.0L will always leak. If it doesn't then it's out of oil. Also alot of people run 15w-40 rotella in the 4.0L so it should like it.
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Keep adding a quart of oil every 1000 miles, and only change the filter every 5000!
 
The rear main ain't leaked yet but I just got it done. I think where the bearing were so wore it gave the crank enough slack to wear out the rear main
 
yoder519 said:
Thanks John for the info. I wish I had seen this before I put the motor back together last night. The bearings were extremely wore down to the brass. Got everything back together just to see the oil pressure only go up to 12psi at idle and 22psi when your driving it. That's with 10w-30 so as soon as O'Reilly's opens up this morning im gonna go get some 15w-40 Diesel oil and put in it and see what kinda pressure I got. And now im in the market for a 2000+ 4.0L for a Cherokee. Good motor or bad its gonna get rebuilt. You know of any John?
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I got one for 500 runs great came out of 98 with only 137K. let me know
 
88jeepster said:
I got one for 500 runs great came out of 98 with only 137K. let me know
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Hey thanks ill keep you in mind Im to the point now that im tired of messing with it and were just gonna drive it til it goes then get one.
 
yoder519 said:
Hey thanks ill keep you in mind Im to the point now that im tired of messing with it and were just gonna drive it til it goes then get one.
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Might as well go ahead and get one on an engine stand and get it ready to drop in. When the one in the truck goes, you dont want to be scrambling to find a new engine.
 
im moving soon probably, so id like to sell that motor to not load up so anyone, 500 bucks take it, tons of other jeep parts too.
john 828-217-0730
 
Yea Brian your right but we do have an extra vehicle and to be honest, after buying the Jeep, putting some cash in it, having to buy a new ridin mower and weed eater cuz mine ate the dust, and paying 2500 bucks to get my wisdom teeth cut out.. Im broke!!!!!
 
Later model 4.0's have a chronic issue with cam bearing wear causing low oil pressure. Essentially 99 and newer 4.0's are much more likely to exhibit low oil pressure than older ones at the same mileage.
A real overhaul will always include cam bearings too.
Let me know if you need some good accurate help!
 
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