Thanks, great to hear from folks who have experience with this particular engine. I have looked in to a HV pump, however that would only up the pressure by ~20% IIRC plus there is an issue with oil pan interference from what I've read - requires some modification to the pan. Not ruling it out, but if the Edge 5w50 is a good choice, then I'm OK with current OP.
"Loose" Jeep 4.0L
- Thread starter 36yrsinTX
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Originally Posted By: 1345
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
I'd actually seen that NAPA filter recommended for the 4.0L on another forum, and have one on there now. Made no diff in OP, however.
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
I'd actually seen that NAPA filter recommended for the 4.0L on another forum, and have one on there now. Made no diff in OP, however.
Originally Posted By: 1345
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
That last line just sounds so wrong......
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
That last line just sounds so wrong......
Originally Posted By: KCJeep
Highly doubt it's the oil pump, very seldom do they go out on the 4.0 and virtually unheard of at 62k.
While I don't completely disagree with this, I have to say that I am not impressed with the upper oiling of factory pumps. The typical life expectantcy is 150K +/- though, so at 62K, it should be OK. I like to install Melling high volume units in my off road rigs and friends Jeeps.
Check the pressure sensor. The factory units are not known for their reliability. Given the engine noise, one thing I would also check, would be the cam drive gear. I've had a few friends who had this strip out. If this is not the issue, replace the oil pump with a Melling High Volume. They are easy to do. If you use the Felpro one piece gasket, it's roughly a 2-3 hour job.
Highly doubt it's the oil pump, very seldom do they go out on the 4.0 and virtually unheard of at 62k.
While I don't completely disagree with this, I have to say that I am not impressed with the upper oiling of factory pumps. The typical life expectantcy is 150K +/- though, so at 62K, it should be OK. I like to install Melling high volume units in my off road rigs and friends Jeeps.
Check the pressure sensor. The factory units are not known for their reliability. Given the engine noise, one thing I would also check, would be the cam drive gear. I've had a few friends who had this strip out. If this is not the issue, replace the oil pump with a Melling High Volume. They are easy to do. If you use the Felpro one piece gasket, it's roughly a 2-3 hour job.
Originally Posted By: 36yrsinTX
IIRC plus there is an issue with oil pan interference from what I've read - requires some modification to the pan.
This is NOT the case. I have installed HV pumps in 2.5L, 258's and 4.0L's without one fitment issue.
IIRC plus there is an issue with oil pan interference from what I've read - requires some modification to the pan.
This is NOT the case. I have installed HV pumps in 2.5L, 258's and 4.0L's without one fitment issue.
napa has diferent filters ask for a platinum.
Originally Posted By: Zaedock
Check the pressure sensor. The factory units are not known for their reliability. Given the engine noise, one thing I would also check, would be the cam drive gear. I've had a few friends who had this strip out. If this is not the issue, replace the oil pump with a Melling High Volume. They are easy to do. If you use the Felpro one piece gasket, it's roughly a 2-3 hour job.
The sensor was the 1st thing I replaced. Per OP, I've verified pressure w/ mech gauge - identical reading to electric gauge.
OK, I'd ruled out a HV pump, will reconsider, given your 2nd post re: fitment. Don't know what the other people were installing, have seen several posts on Jeep forums saying pan needs to be "adjusted" with a ball-peen hammer.
Some engines (Ford 302 is one I know of) experience twisted pump drives w/HV pumps. Evidently that is not an issue in the 4.0L?
Thanks much!
Check the pressure sensor. The factory units are not known for their reliability. Given the engine noise, one thing I would also check, would be the cam drive gear. I've had a few friends who had this strip out. If this is not the issue, replace the oil pump with a Melling High Volume. They are easy to do. If you use the Felpro one piece gasket, it's roughly a 2-3 hour job.
The sensor was the 1st thing I replaced. Per OP, I've verified pressure w/ mech gauge - identical reading to electric gauge.
OK, I'd ruled out a HV pump, will reconsider, given your 2nd post re: fitment. Don't know what the other people were installing, have seen several posts on Jeep forums saying pan needs to be "adjusted" with a ball-peen hammer.
Some engines (Ford 302 is one I know of) experience twisted pump drives w/HV pumps. Evidently that is not an issue in the 4.0L?
Thanks much!
Originally Posted By: addyguy
Originally Posted By: 1345
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
That last line just sounds so wrong......
Oh sorry I didn't mean it that way.
Originally Posted By: 1345
What kind of oil filter are you useing? Try a napa platinum 41515 filter and rotella t6 oil. My cherokee 4.0 idles at 21 psi hot. Before this filter it would idle at 12 psi hot. I live in south central Texas. rotella t6 even made my dipstick slide out smoother.
That last line just sounds so wrong......
Oh sorry I didn't mean it that way.
I have the same year and model Cherokee but has about a 100K more miles on then yours. It too has what I would say sounds like a sticky lifter...although sometimes I hear it and other times not at all and everything in between. I started out with 10W-30 in the first oil change in May shortly after I bought it.
Think I used plain old Castrol 10w-30 by the jug from Walmart and a Purolator filter.
The last OC I used 10w-40 Pennzoil YJ and a NAPA Silver filter.
It was quieter for sure and the oil pressure increased. I did replace the oil pressure switch early on because it was way wack.
It's not a quiet engine but I don't care about the sound because I'm pretty sure this thing will go another 100K with minimal maintenance.
I have a NAPA Gold filter and Super Tech 10w-40 High Mileage on deck for the OC but was thinking of trying Shell Rotella 5w-40 Full Syn. instead...I have doubts it's worth the extra $$$ though.
Think I used plain old Castrol 10w-30 by the jug from Walmart and a Purolator filter.
The last OC I used 10w-40 Pennzoil YJ and a NAPA Silver filter.
It was quieter for sure and the oil pressure increased. I did replace the oil pressure switch early on because it was way wack.
It's not a quiet engine but I don't care about the sound because I'm pretty sure this thing will go another 100K with minimal maintenance.
I have a NAPA Gold filter and Super Tech 10w-40 High Mileage on deck for the OC but was thinking of trying Shell Rotella 5w-40 Full Syn. instead...I have doubts it's worth the extra $$$ though.
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Is there anyway you can get another reading with that OP gauge? 8 at idle with a 30weight does sound a tad low. I know the instrument cluster gauge is inaccurate but how's it comparing to the OP gauge you had hooked up?
Honestly I wouldn't be to worried about it, my '94 is 15-17 at idle with a 30weight and barely hits 35 at 2K, been like that for 175K so far.
Honestly I wouldn't be to worried about it, my '94 is 15-17 at idle with a 30weight and barely hits 35 at 2K, been like that for 175K so far.
Originally Posted By: Toros
I have the same year and model Cherokee but has about a 100K more miles on then yours. It too has what I would say sounds like a sticky lifter...
Toros, the internal noises I hear at idle are not lifters. However, bad lifters are pretty common for this engine. My previous 4.0L was in an '02 Wrangler, also with less than 70K on the clock. I had lifter noise at start-up, which got more common as time passed. If that is not addressed (I did), it will destroy the camshaft, and the cost to repair multiplies. Look into it if you start getting that stuck lifter noise at cold start.
The noise I'm hearing is either piston slap or wrist pins, but it has gotten more noticeable with the 5W Edge. When the weather cools in a few weeks, I'll go to a 10W-40, probably Amsoil.
I have the same year and model Cherokee but has about a 100K more miles on then yours. It too has what I would say sounds like a sticky lifter...
Toros, the internal noises I hear at idle are not lifters. However, bad lifters are pretty common for this engine. My previous 4.0L was in an '02 Wrangler, also with less than 70K on the clock. I had lifter noise at start-up, which got more common as time passed. If that is not addressed (I did), it will destroy the camshaft, and the cost to repair multiplies. Look into it if you start getting that stuck lifter noise at cold start.
The noise I'm hearing is either piston slap or wrist pins, but it has gotten more noticeable with the 5W Edge. When the weather cools in a few weeks, I'll go to a 10W-40, probably Amsoil.
Originally Posted By: gomes512
Is there anyway you can get another reading with that OP gauge? 8 at idle with a 30weight does sound a tad low. I know the instrument cluster gauge is inaccurate but how's it comparing to the OP gauge you had hooked up?
Honestly I wouldn't be to worried about it, my '94 is 15-17 at idle with a 30weight and barely hits 35 at 2K, been like that for 175K so far.
Sure, I could get another reading, but I'm not sure of the reason to do so. Electric (dash) gauge reading has been verified. (Reading with the original OP sender was around 8 @ hot idle. Replaced the sender, still 8 @ hot idle. Pulled off the sender and put in a (temporary) mechanical gauge. Still 8 psi when hot.) As I understand it, below 8PSI, the "Check gauges" light will come on, which tells me that is just too low, even for this engine, and time to worry. My previous 4.0L carried 30 psi @ hot idle and close to 50 at 2K rpm. It also had less than 70K on the clock, so I know this engine has some sort of internal problem. I still think it is good for many miles yet, IF I am able to minimize further damage. Question is, what's the best route? HDEO, HMO, HV pump, or. . . ??
I will be doing a UOA at the next OC to determine whether accelerated wear is still occurring.
Is there anyway you can get another reading with that OP gauge? 8 at idle with a 30weight does sound a tad low. I know the instrument cluster gauge is inaccurate but how's it comparing to the OP gauge you had hooked up?
Honestly I wouldn't be to worried about it, my '94 is 15-17 at idle with a 30weight and barely hits 35 at 2K, been like that for 175K so far.
Sure, I could get another reading, but I'm not sure of the reason to do so. Electric (dash) gauge reading has been verified. (Reading with the original OP sender was around 8 @ hot idle. Replaced the sender, still 8 @ hot idle. Pulled off the sender and put in a (temporary) mechanical gauge. Still 8 psi when hot.) As I understand it, below 8PSI, the "Check gauges" light will come on, which tells me that is just too low, even for this engine, and time to worry. My previous 4.0L carried 30 psi @ hot idle and close to 50 at 2K rpm. It also had less than 70K on the clock, so I know this engine has some sort of internal problem. I still think it is good for many miles yet, IF I am able to minimize further damage. Question is, what's the best route? HDEO, HMO, HV pump, or. . . ??
I will be doing a UOA at the next OC to determine whether accelerated wear is still occurring.
my cousin has the same jeep year and all and he uses pennzoil 10w30 hm..
this 4.0 has over 250,000 beat on miles and it has been knocking ticking and had low oil pressure for the last 100,000 miles this guy lets his 18 year old son redline this thing and it still runs, i told him when it finally blows i want the head as long as it was not clobbered by a piston..
Those jeep 4.0 engines are great they are not quiet but they last
this 4.0 has over 250,000 beat on miles and it has been knocking ticking and had low oil pressure for the last 100,000 miles this guy lets his 18 year old son redline this thing and it still runs, i told him when it finally blows i want the head as long as it was not clobbered by a piston..
Those jeep 4.0 engines are great they are not quiet but they last
I'd start by pulling the pan and getting idea of whats going on. That should give you an idea of where to go next. If you need metal shavings sitting in the bottom of the pan, then you know it's time for a rebuild/junkyard motor swap. If it's clean and the pick up is clean, then I'd try a new oil pump and see what happens. If it's worn out enough that the oil pressure is that low, I'd assume there would be some excessive wear metal hanging out in the bottom of the pan. If it's another cause, like the pump or a plugged pick up, then it'd be best to take care of it right away. In the mean time, running a thick oil like that would probably be the best course of action. Though I would pull the pan as soon as you can to check things out...it'd suck to find a "simple" repair could have fixed it if it lets loose before you tear into it.
Originally Posted By: jjcom
I'd start by pulling the pan and getting idea of whats going on. That should give you an idea of where to go next. If you need metal shavings sitting in the bottom of the pan, then you know it's time for a rebuild/junkyard motor swap. If it's clean and the pick up is clean, then I'd try a new oil pump and see what happens. If it's worn out enough that the oil pressure is that low, I'd assume there would be some excessive wear metal hanging out in the bottom of the pan. If it's another cause, like the pump or a plugged pick up, then it'd be best to take care of it right away. In the mean time, running a thick oil like that would probably be the best course of action. Though I would pull the pan as soon as you can to check things out...it'd suck to find a "simple" repair could have fixed it if it lets loose before you tear into it.
Thanks for the input. I'm going to do a UOA at the next drain, so that should give me a pretty thorough reading of what's going on internally. If there's metal, it will tell me what it is most likely coming from.
If it is NOT abnormal, an OP is not a difficult nor expensive repair, just to see if it will help, and I'll probably do that.
But if I still have bearing material grinding off the cam (for example) at a high rate, it would be useless to replace the pump, of course.
I'd start by pulling the pan and getting idea of whats going on. That should give you an idea of where to go next. If you need metal shavings sitting in the bottom of the pan, then you know it's time for a rebuild/junkyard motor swap. If it's clean and the pick up is clean, then I'd try a new oil pump and see what happens. If it's worn out enough that the oil pressure is that low, I'd assume there would be some excessive wear metal hanging out in the bottom of the pan. If it's another cause, like the pump or a plugged pick up, then it'd be best to take care of it right away. In the mean time, running a thick oil like that would probably be the best course of action. Though I would pull the pan as soon as you can to check things out...it'd suck to find a "simple" repair could have fixed it if it lets loose before you tear into it.
Thanks for the input. I'm going to do a UOA at the next drain, so that should give me a pretty thorough reading of what's going on internally. If there's metal, it will tell me what it is most likely coming from.
If it is NOT abnormal, an OP is not a difficult nor expensive repair, just to see if it will help, and I'll probably do that.
But if I still have bearing material grinding off the cam (for example) at a high rate, it would be useless to replace the pump, of course.
I Currently have 4 Cherokees with the Four Point Oh, one of which, my latest buy, a 2000 Cherokee with a badly cracked cylinder head after 213,??? miles is under the Knife with a complete rebuild currently under way, and the Only thing that that Chocolate colored motor oil/Coolant(More like Rust water)was completely Destroy the cam bearings. And I Believe this XJ was driven for AWhile with a cracked head before it finally ran out of "Coolant"(RustWater) and overheated like a.... If I were you, I would use HD30 or 20w-50 SuperTech,. for real. It will be a band-aid until you plan what to do for a new or rebuilt motor. Or have your current motor repaired with a Deeper Cam and new bearings. I also have a 2001 Cherokee with I believe 64,820 miles current,. Shes a SilverStone Metallic Sport with the sunroof, AW-4 4 speed auto, NP231 4x4, non ABS Dana 30 Low-pinion front Chrysler 8 1/4 rear. Ive used everything from Mobil 1 Extended 10w-30 to SuperTech 10w-30 in her.
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My 99s Four Point Oh was rebuilt last summer due to #2 Wrist Pin egging out #2 piston. I swore it was a lifter foot or cam lobe worn out also, as did alot of other people. ReBUILD is doing very well over 1100 Hard Break-In miles with stock 139,??? mile oil pump still in use with the 35-40 Hot(15 min HighWay driving)Psi she had before she was torn apart. A HIGH Volume pump is still only a band-aid for worn bearings. Pull the oil pan, and reach up to the camshaft and try moving it up and down. I bet it will move due to worn cam bearings. I am able to move the cam in my 2000 XJs 4.0 more than 30 thousand of an inch,..dems worn bearins'. The brand of engine bearings changed in 2000, with more Durable Rod and Main bearings, and less durable cam bearings IMHO.
There just shouldnt be any sludge or worn out oil pumps at that mileage, unless only 2 or 3 oil changes have been performed since 2001. My 2001 XJ was beat bad before I got her in 2006 with 49,??? original miles, and She still has 30+Psi when Hot. My 99s has even better oil pressure when Hot and has more than 140,000 miles on her odometer currently with Pennzoil Yellow Bottle 10w-30 in her sump. Has the Coolant Mysteriously been dissapearing? Oil pressure sending units routinely go bad before they should in these later year 4.0z also. Fill her up with QuakerState or SuperTech 20w-50 and see what happens is what I would do. In that Heat, it wont hurt a thing.
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OK, the full story on my 2001 Cherokee is that I hear what sounds like lifter noise about 15 seconds after cold startup. Then it gets louder until I drive her for some time and she gets good and hot. Then I hear it, but not very much and it is a way "softer" sound. I intend to do nothing but change the oil and use either 10w-30 or 10w-40 dino oil and a basic but decent filter. I have changed all other fluids and done all else to get her/keep her running and with 164K on her, I think she still have a few good years left. I don't off road and I don't haul anything but surfboards on the roof and an occasional honey do load from Home Depot or Lowes. I have driven all kinds of cars in my time, but I love this Jeep more then any of them. In fact, I have taken to seeking out another. What's the ideal year? I'm thinking 96-98? What do you guys think?
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