Which Oil For : 1995 Jeep Cherokee I-6 Cylinder?

[slomo]

5w-30 in winter and a 10-40 in the summer. Change it twice a year regardless of miles. Starts turning cold, in goes the 5w-30. Starts to get hot, in goes the 10w-40.

I have an older CJ7 with the 4.2. My winter oil is Trop Artic from Sam's @ $26.12 per case everyday. Sam's doesn't carry their 10w-40 so I use Rotella 15w-40 in the summer.

That Trop Artic must be full of detergents. After a valve cover gasket replacement, there was zero sludge under the valve cover. It was all super clean under there and on top the cylinder head. I can't even see it on the stick it's so clean. Have to take the dipstick outside in the sunlight to find the level. I've ran the Trop Artic solely to back up the oil cleanliness claim for a while.

 

[Kuato]

Originally Posted By: ChrisD46
Thanks for the replies !
Looks like PYB , QS Defy and Rotella Triple T dino oils in 10W30 would work year round ...Anyone drop down to a 5W in their Jeep 4.0L I6 engine for a winter OCI when temps may dip down into the occasional teens at night ?


Yup, ran 5w and 0w30 for several years without issue.

 

[Kuato]

Originally Posted By: ChrisD46
Love hearing the Jeep 4.0L XJ owners talk about their oil favorites !

Will add Mobil and Super Tech to the list (WM less than 1 mile from house) . Will add the oil filter will be WIX or NAPA Gold ...

Lastly curious about OCI's with the big 4.0L sump (6 qrts) : Is 5,000 miles OCI OK for average suburban driving style ? No manual with the '95 Jeep so no idea what Jeep stated for normal OCI and severe OCI ?


Sorry to have missed this earlier. All of mine.said 3000 severe, 6000 normal. All the UOAs I did at 5k showed plenty of additive left.

 

[ChrisD46]

A look under the oil fill cap is OK on this '95 4.0L I6 engine - could be a little cleaner though as this Jeep XJ may have been short tripped a bit with dino . Which oil would you give the nod to for cleaning ability : PYB 10W30 or Rotella Triple T 10W 30 ? ... I would plan to run a shorter first OCI (<3,000 miles) and monitor accordingly . * I considered to add 15% MMO to the first OCI (as done with success in previously bought used vehicles) - but now on the fence due to potential oil seal leak issues with this engine - may be best just to let the add pack of PYB or Rotella do it's own thing slowly and (again) monitor) . Your thoughts ?

 

[Lex94]

Anyone ever try PYB 20w50?

 

[ChrisD46]

Additionaly - what normal oil pressure readings would you say are good with the '95 Jeep 4.0L I6 ? Through research I could only find one reference to 13 psi at idle as being good - could not find any normal oil pressure references at higher speeds - please advise ?

 

[Zaedock]

The oil pressure spec is 37PSI at 1600 RPM. At idle, it should be between 25-35 PSI.

I have played with many oils over the years in all of my Jeeps and have settled on GrpIII 5W30's for my trail rigs and 5W30 for the drivers. The pro's, such as decreased parasitic loss and better cold start flow outweigh any perceived con's.

 

[Zaedock]

Originally Posted By: ChrisD46
Anyone drop down to a 5W in their Jeep 4.0L I6 engine for a winter OCI when temps may dip down into the occasional teens at night ?


I ran Quaker State Q-Horsepower (older version of Ultimate Durability) 5W30 for two years in my 2.5L, including a trip to Moab, UT. No issues at all and UOA was fine (despite several roll overs too).

I plan to experiment with 0W20 oils in my Jeep 2.5L buggy project. I'll see how it works when I add the Saab turbo as well.

 

[dlundblad]

Originally Posted By: KCJeep
Originally Posted By: ChrisD46
Thanks for the replies !
Looks like PYB , QS Defy and Rotella Triple T dino oils in 10W30 would work year round ...Anyone drop down to a 5W in their Jeep 4.0L I6 engine for a winter OCI when temps may dip down into the occasional teens at night ?


You've done some reading! Those are fantastic oil choices right there. Your Jeep was spec'd for 10w30 but probably allows 5w30, I doubt you need it at all in your climate. I am convinced the Jeep 4.0 will do best on a thicker 30 or lighter 40 grade, but as mentioned it'll run near forever on about anything. I'd add 10w40 Maxlife to your list of possibilities as well.

If you like quiet save yourself the trouble and just go PYB. I do run 5w30 in the very cold months but that's it, much thicker the rest of the year. Currently running Pennzoil HM which is a thick 30, got my best UOA so far on Pennzoil 10w40 though.


KC, don't you recommend a shorter (2500-3000) OCI for the 5w 30 PYB?

 

[ChrisD46]

Please confirm oil weight choices again - did you mean to say 5W30 for the Drivers ?
Originally Posted By: Zaedock
The oil pressure spec is 37PSI at 1600 RPM. At idle, it should be between 25-35 PSI.

I have played with many oils over the years in all of my Jeeps and have settled on GrpIII 5W30's for my trail rigs and 5W30 for the drivers. The pro's, such as decreased parasitic loss and better cold start flow outweigh any perceived con's.

 

[Zaedock]

Originally Posted By: ChrisD46
Please confirm oil weight choices again - did you mean to say 5W30 for the Drivers ?
Originally Posted By: Zaedock
The oil pressure spec is 37PSI at 1600 RPM. At idle, it should be between 25-35 PSI.

I have played with many oils over the years in all of my Jeeps and have settled on GrpIII 5W30's for my trail rigs and 5W30 for the drivers. The pro's, such as decreased parasitic loss and better cold start flow outweigh any perceived con's.


Yep, 5W30 conventional for the driver's. Modern 5W30's are very sheer stable. There is no need, IMO (been building/wheeling Jeeps for 20+ years), for 10W30 or 40 wts. I beat my Jeeps more than anyone here and although I used to be old school on viscosity, I have found modern Grp III 5W30's to perform excellently in extreme use and conventional 5W30's for driver's. Jeep 258/4.0L/2.5L 's are not picky on oil.

 

[ChrisD46]

Just so I don't rule out a synthetic 5W30 such as M1 0W30 , 5W30 or SOPUS PUP / QSUD 0W30 , 5W30 : If I used a GRP III synthetic and started having leaks due to high mileage - can I assume if I go back to a dino 5W30 that the leak(s) would self correct and stop ?

 

[ChrisD46]

Yes , would be curious if dropping to 5W30 PYB would require a shorter OCI (2500 ~ 3000) as another poster noted vs. a 10W30 ?

 

[Alex38]

My first thought for your application was 10w30 MaxLife. It would protect that engine well, and may also help with the rear main leak issue. I'd also consider 5w30 Maxlife if you're in Northern GA- due to winters- or if you do a lot of short trips. You could also always switch to MaxLife full synthetic if you wanted to.

 

[wsar10]

FWIW:
I always drop down to 5W PNZL HM in the winter months in my newer 4.0's, this seems to keep them quiet. I run the T5 the rest of the year, I used to mix for the winter but last winter I went straight HM. I have no UOA's for the HM but in past years I have seen favorable UOA's with this oil in the 4.0

I'm second guessing my winter choice this year as I am getting tired of stocking multiple oils, I'm thinking T6 but at this time I have a leaky valve cover gasket and no time to fix till next summer (probably),I wish you could get T5 in 0-30 or 5-30.....

I must add, I would stick with a HDEO although there are other solid choices just try to stay in the upper 30wts or light to mid 40. Good advice from KC as usual on these motors.

I personally have never been a fan of M1 in these engines (or any Ive owned) based on a subject of great debate around here, I just simply cant ignore high FE trends.

 

[ChrisD46]

Well after driving the "mini beast '97 Jeep XJ Cherokee for three days and parking it over night - not one drop of oil on the pavement (190K miles on her) ! The previous owner changed his own oil and the window sticker said "MS5K" and 2K more miles before next oil change due ... No Rotella Triple Protection T 10W30 at my local WM , so decided for my first oil change to go with PYB 10W30 and run it until around Thanksgiving . Then change to either PYB 5W30 or take a look at one of the HM oils suggested in this thread . * Biggest fear is introducing an oil that would cause this 4.0L to start leaking (especially now that I have no leaks at all) .

 

[wsar10]

You must have the only 4.0 in the world with no leaks !!
I bought an 04 WJ in 06 and the [censored] VCG leaked !! I'm pretty sure all 10 4.0's I have owned marked there territory in some way.....

They usually have wet RMS or VCG (rear main seal, valve cover gasket).

2 VERY IMPORTANT views of mine....

A) oil leaks (within reason) do not concern me, I check the dip-stick once a weak to monitor oil level.

B) JEEPs do NOT leak they mark there Territory !!!!!

PS,
You made a good choice IMO, I would rather use the HDEO but PYB is one of the best !

 

[ChrisD46]

I notice in your sig that you use Rotella T5 primarily ...Not saying that is why your 4.0L's leak but I do have the question of perhaps too good of cleaning in Rotella synthetics which may contribute to 4.0L's leaks ?

 

[wsar10]

Originally Posted By: ChrisD46
I notice in your sig that you use Rotella T5 primarily ...Not saying that is why your 4.0L's leak but I do have the question of perhaps too good of cleaning in Rotella synthetics which may contribute to 4.0L's leaks ?
l

I'm sure it does contribute, but they have all leaked before me switching them to the T5, the syn-blend isnt as bad as a full syn plus I think being a HDEO helps to maybe combat the leak a bit vs a PCMO syn-blend. They dont leak to the point that there is a "puddle" of oil left behind, they are just "damp" (current ones anyway). I have the VCG to do all 3 but not the time....(I have other vehicles that wont fit in my sig)

All that being said I am currently considering going to T6 all year around (in the 04), but my concern is the VCG leak gets noticeably worse until next summer, in the end I think im gonna do it and just keep an eye on it, I'm even considering a run of the DELO 5-40.

You always see the expression; "its a JEEP thing you would'nt understand".....well the "JEEP think" is oil leaks and rust !!LOL

 

[ChrisD46]

Thanks for sharing - the nuinces Jeep owners provide regarding oil choices is invaluable !