jeep 4.0

[chuck172]

I recently bought a 1993 Jeep Wrangler with the 6cy. 4.0. The jeep has 90,000 miles and runs great. This Jeep doesn't leak oil nor does it burn any.
I've been reading about using Rotella diesel oil for this engine because of the added sulfer content of the oil.
Should I go with this oil? Should I go with the synthetic version of Rotella? Will it harm the cat. converter?

 

[dave1251]

Rotella is great choice but the Jeep 4.0 is not that picky just pick a good 30 or 40 grade and it will go on forever.

 

[Doog]

I would use the 15w40 but neither will hurt it.

 

[electrolover]

No harm in running rotella. I would probably choose the T5 10w 30 because its a syn blend and cost effective. T6 5w40 would work well too.
I believe Motorcraft makes a filter that would fit your application. If so thats the way I would go. They perform well and are cost effective.


Welcome to BITOG!

 

[callbay]

Hey Chuck,

We have a 98 Wrangler 4.0 with just over 100,000 on it. We use 5-40 Rotella synthetic and it has been great. No problems whatsoever.

 

[Donald]

Maybe I should go to T6 in my Jeep also, as then I would only need to purchase T6 for both vehicles.

 

[bullwinkle]

Had Rotella 15W40 in the Cherokee-one day it got down close to 0F, it started but didn't crank very fast, switched it to MaxLife 5W30, much better. The 4.0 will probably be OK on just about any decent oil, and CJ-4 diesel oils have lower ZDDP levels, so catalyst damage shouldn't be a concern either.

 

[Since1941]

Hey man, I am running Rotella T6 in my Jeep, and it has been great. It has been pretty cold here in Ohio, and I have had no problems. I have had a few 4.0's before my 2.5L and they are not picky. I'd say run that, and grab a Fram Tough Guard TG16, or Pureone filter. However, I get a little dry starts, and noise with the Pureones. A lot of guys I talk to with the 4.0 get no issues with the Tough Guard. The Motorcraft is a great option too, and is highly regarded. Welcome!

 

[KCJeep]

Lots of great input already posted, good job guys!

Rotella is a good fit for the 4.0 but you don't have to have it. If you're concerned about ZDDP there is also Defy available, but I haven't seen anything that has convinced me higher ZDDP makes much difference in the 4.0 once it's properly broken in.

Like posted above they'll run on near anything just fine but they are indeed fun to pamper, I'd suggest a good reasonably thick 30 grade at a minimum. IMO a 15w40 is overkill and won't gain you a thing, a 10w40 on the light side would still be viable though.

After exhaustive filter experimentation I can concur Motorcrafts absolutely rock on this engine, and as mentioned Tough Guards seem to work really well at start up on them as well. I've had start up noise with many other highly regarded filters including PureOne's, but my previous two 4.0's were not nearly as filter picky so they are not all alike in that regard.

Best start ups for me have been with Motorcraft "S" series filters, Tough Guards are just about as good and have a much higher filtering efficiency rating, the nitrile ADBV Motorcrafts like the FL-1A work really well also, most, but not all of the time when it's cold out.

The FL-910S/PH3614 series, the FL-400S/PH3600 series, the FL-300/PH16 series and the FL-1A/PH8A series filters will all fit and work well on your 4.0, but the only "spec'd" filter are the PH16 equivalents, so anything else you run is at your own risk.

That said it's been over a year since I ran a spec'd filter, no problems.

 

[chuck172]

Is Quaker State Defy a conventional or synthetic motor oil? What weight do you recommend?

 

[KCJeep]

Originally Posted By: chuck172
Is Quaker State Defy a conventional or synthetic motor oil? What weight do you recommend?


It's a blend and a value priced one at that, about $15 for a 5 qt jug at Wally's. I think AAP also has it on sale for 3 bucks a quart. Defy is a blend, has elevated ZDDP levels as well as a good dose of boron and a shot of moly. Good match for the Jeep.

The only UOA I've found on Defy was in a Jeep 4.0 and it looked real good, a 5k run.

If you're going to use Defy now you'd be best served by using 5w30 Defy (it's a little thicker than most 5w30's), but for summer I'd want the 10w30 version of Defy.

My next change is going to be Defy in 5w30, it's coming soon and I'll end up running that until early June but then the heat waves will start I'll want something thicker.

 

[84zmyfavorite]

German Castrol and Purolator 30001 oil filter, if no leaks. My 2001 SilverStone Jeep Cherokees 64,820 mile 4.0 will be receiving this soon. I currently have 7 Cherokees, 5 of which have the 4.0, from my 87 with 297,909 miles, 96 with 250,5??, 99 with 141,300, my newest, a Gold 2000 with cracked 0331 being ReBUILT with no oil it her, and my 2001 with 64,820 miles that doesnt seem to care What kind of oil She receives. They Really dont mind What Brand (Accel to AMSOIL)or what base oil(GroupI to Group5...Motul 300v Favorite) is used, just as long as there is 6 quarts and a Tight oil filter, a 4.0 will be Happy. 2.5s like 3 to 4 quarts,..3 being the least.

 

[84zmyfavorite]

Around here, Autozones are having $33.99 deal of 5 Quarts Castrol Syntec with Bosch Distance Oil filter. I cant seem to buy anything else but the 0w-30(Made In Germany). Why bother with any thing else? Most Jeep 4.0s LOVE this oil. I havent put it in any HIGH Mileage 242 Inline 6s though, Yet. My 87 with 297,909 miles is due in 91 miles...

 

[cb_13]

FL1A or FL300 both fit on a 4.0 jeep. I run the FL1A on my moms cherokee.

 

[chuck172]

Napa Gold #1515...Purolater Premium Plus #L30001..Motorcraft FL-1A...Baldwin B2
All oversize filters.

 

[KCJeep]

Originally Posted By: 84zmyfavorite
Around here, Autozones are having $33.99 deal of 5 Quarts Castrol Syntec with Bosch Distance Oil filter. I cant seem to buy anything else but the 0w-30(Made In Germany). Why bother with any thing else? Most Jeep 4.0s LOVE this oil. I havent put it in any HIGH Mileage 242 Inline 6s though, Yet. My 87 with 297,909 miles is due in 91 miles...


I've got some Castrol 0w30 in the stash for mine as well due to the recent AAP BOGO sale. Can't wait to get to it, never run it before but it looks like a great match for the 4.0 I plan to run it a full 10k.