2006 Jeep Liberty 3.7 65,000mi

[NineFingerFury]

I looked at the "Best Oil" sticky and thought I'd answer some questions to help find the answer to my own question—Which oil/filter combo should I use, and how long should I attempt to make my OCI?

I am currently using whatever the dealer put in just over 1,000mi ago when I bought it.

I just bought some Mobil 1 Extended Performance oil/filter on sale and am hoping to get a 1-year OCI because of my milage/year.

1. What kind of vehicle you have

2006 Jeep Liberty Limited 3.7L V6 42RLE auto trans

2. What your owner's manual says -- not just viscosity, but certifications (look for acronyms like API SM, ILSAC GF-4, etc.) and change intervals as well

From the owner's manual:

Change Engine Oil
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:

• Day or night temperatures are below 32°F (0°C)
• Stop and go driving
• Extensive engine idling
• Driving in dusty conditions
• Short trip driving of less than 10 miles (16.2 km)
• More than 50% of your driving is at sustained high speeds during hot weather, above 90°F (32°C)
• Taxi, Police, or delivery service (commercial service)
• Trailer towing
• Off-road or desert driving

If ANY of these apply to you, then change your engine oil at every interval shown in schedule “B” of the “Maintenance Schedules” section of this manual.

If none of these apply to you, then change your engine oil at every interval shown on schedule “A” of the “Maintenance Schedules” section of this manual NOTE: Under no circumstances should oil change intervals exceed 6,000 miles (10 000 km) or 6 months whichever comes first.

Engine Oil Selection (Gasoline Engines)
For best performance and maximum protection for all engines under all types of operating conditions, the manufacturer recommends engine oils that are API Certified and meet the requirements of DaimlerChrysler Material Standard MS-6395.

The manufacturer only recommends API Certified engine oils.

Engine Oil Viscosity (3.7L Engines)
SAE 5W-30 engine oil is recommended for all operating temperatures. This engine oil improves low temperature
starting and vehicle fuel economy. Your engine oil filler cap also shows the recommended engine oil viscosity for your vehicle.

Lubricants which do not have both, the engine oil certification mark and the correct SAE viscosity grade number should not be used.

---
Schedule "A" says 6,000mi or 6/mo for OCI.
Schedule "B" says 3,000mi or 3/mo for OCI.

Since I do a lot of short trips (under 10mi) should I consider myself to be on the "B" schedule?

3. Where you live

Western Washington (State)

4. How you drive (easy? hard? fast? slow?)

I've heard for the best milage to try and keep it below 3k RPMs, so that's what I do.

5. What your daily drive is like (short trips? long trips? city? highway?)

Mainly backroads and around town with the occasional highway trips when my wife wants to us take the Jeep because she likes it better than her 2009 Corolla S.

To work and back (most days) is just under 10 miles each way on backroads, going about 40-45mph.

According to my iPhone app (Gas Cubby), I drive an average of 30mi per day. This comes out to just under 11,000mi/yr.

6. Whether your car has any known problems

No known problems. I just changed out the front and rear diff fluid with 80w90 Valvoline, and the transfer case and transmission (dropped pan and replaced filter) with Valvoline ATF+4. Runs like a dream.

 

[jimbrewer]

You know what? You aren't going to go wrong following the manual.
I think there is an issue with M1 not quite being certified for some Chrysler engines, so there is that, although its a minor thing since you are out of warranty.

I found it instructive to buy a couple of UOAs. I found out a couple of things. One was that regular name brand oil has a lot of capability. Another was that these additives they put in your oil need to cook a little to be most effective. If you really have a lot of short haul trips, its hard for the M1 EP--as good as it is-- to make up for that. Better to use a more plebian oil and change more often, like the manual says.

So, if I were you, I would change on the severe schedule and sample. If the test is good, and I expect it will be, go to 6K on the same oil and test again, getting TAN. If that's good (i.e. not marginal) then you know what to do.

 

[toneydoc]

I would look at your convenient auto part store sales circulars and look for good quality oil and a name brand filter such as Purolator Pure One or equivalent. They usually combine oil and filters into specials. Buy the quality oil, either synthetic or conventional, and oil filter and change it twice a year. And buy the oil in 5w30 as recommended by Jeep.

 

[zrxkawboy]

Originally Posted By: NineFingerFury

for all operating temperatures. This engine oil improves low temperature

4. How you drive (easy? hard? fast? slow?)

I've heard for the best milage to try and keep it below 3k RPMs, so that's what I do.



Can I throw in something non-oil-related? These engines have an issue with misfiring when carbon builds on the exhaust valves. Supposedly, the valves do not rotate (which helps clean the carbon) until >4000 rpm. Therefore, I use a good fuel additive in ours, and occasionally give it a full-throttle run through the gears.

 

[NineFingerFury]

Originally Posted By: zrxkawboy


Can I throw in something non-oil-related? These engines have an issue with misfiring when carbon builds on the exhaust valves. Supposedly, the valves do not rotate (which helps clean the carbon) until >4000 rpm. Therefore, I use a good fuel additive in ours, and occasionally give it a full-throttle run through the gears.


Thanks. I'm running my fuel down now to add Techron Concentrate Plus.

 

[NineFingerFury]

Originally Posted By: jimbrewer
You know what? You aren't going to go wrong following the manual.
I think there is an issue with M1 not quite being certified for some Chrysler engines, so there is that, although its a minor thing since you are out of warranty.

I found it instructive to buy a couple of UOAs. I found out a couple of things. One was that regular name brand oil has a lot of capability. Another was that these additives they put in your oil need to cook a little to be most effective. If you really have a lot of short haul trips, its hard for the M1 EP--as good as it is-- to make up for that. Better to use a more plebian oil and change more often, like the manual says.

So, if I were you, I would change on the severe schedule and sample. If the test is good, and I expect it will be, go to 6K on the same oil and test again, getting TAN. If that's good (i.e. not marginal) then you know what to do.


Sounds good. I'll try and take back the M1 then. PYB and a Wix filter was my other choice.

 

[T_CUDA]

Valvoline WB 3qrts and 2qrts Silver bottle(meets Chrysler spec)and a Pure-One PL20195 every 5k.NGK plugs,PCV and Pure-One air filter every 30k.Rear diff should have been 75w90 full synthetic( I use Valvoline it meets the U.S Mil.Spec)

 

[NineFingerFury]

Originally Posted By: T_CUDA
Valvoline WB 3qrts and 2qrts Silver bottle(meets Chrysler spec)and a Pure-One PL20195 every 5k.NGK plugs,PCV and Pure-One air filter every 30k.Rear diff should have been 75w90 full synthetic( I use Valvoline it meets the U.S Mil.Spec)


I heard not to use synthetic in the diffs because it doesn't stick to the gears as well.

 

[KCJeep]

I'm a big fan of Motorcraft filters on Chrysler products.

 

[mark pruett]

I just got done with a 2.5 year / 10540 mile OCI using 5w-30 Mobil 1 EP and a Motorcraft FL-400S in a 3.7L Dodge Dakota (2005) with the same 42RLE automatic transmission as your Liberty.

Fine UOA- no issues over the course of the OCI either.

UOA LINK

I've generally run 6k intervals over the course of the 8 yrs / 73050 miles I've had the pickup, and I burn VERY little oil. Other oils I've used without issue are PYB, Havoline, Castrol GTX, Exxon Superflo, Pennzoil Ultra & Platinum, Quaker State (green bottle), and Phillips 66 Trop Artic.

I'd think you can do the same, considering that we have basically the same powertrain on the same age vehicle, and roughly the same commute (mine's 9 miles each way, at about 35-40 MPH).

 

[T_CUDA]

I have NEVER seen a diff. go bad from using synthetic, always been a leak and no fluid or 200k on factory conventional fill. Factory fill on the rear diff is synthetic and conventional in the front.

 

[84zmyfavorite]

NineFingerFurry, are you in Wenatchee, WA by chance?

 

[NineFingerFury]

Originally Posted By: mark pruett
I just got done with a 2.5 year / 10540 mile OCI using 5w-30 Mobil 1 EP and a Motorcraft FL-400S in a 3.7L Dodge Dakota (2005) with the same 42RLE automatic transmission as your Liberty.

Fine UOA- no issues over the course of the OCI either.

UOA LINK

I've generally run 6k intervals over the course of the 8 yrs / 73050 miles I've had the pickup, and I burn VERY little oil. Other oils I've used without issue are PYB, Havoline, Castrol GTX, Exxon Superflo, Pennzoil Ultra & Platinum, Quaker State (green bottle), and Phillips 66 Trop Artic.

I'd think you can do the same, considering that we have basically the same powertrain on the same age vehicle, and roughly the same commute (mine's 9 miles each way, at about 35-40 MPH).



Thanks for the info. It's nice to hear from someone in almost the same situation as me. The Motorcraft filter looks like a great option.

 

[NineFingerFury]

Originally Posted By: 84zmyfavorite
NineFingerFurry, are you in Wenatchee, WA by chance?


Nope. Kent, WA. I was in Wenatchee a few weeks ago on my way to and from Chelan though.

 

[NineFingerFury]

Originally Posted By: T_CUDA
I have NEVER seen a diff. go bad from using synthetic, always been a leak and no fluid or 200k on factory conventional fill. Factory fill on the rear diff is synthetic and conventional in the front.


That may be so, but all I ever heard at LOSTJeeps.com and JeepKJ.com was to not use synthetic in the diffs. They have cited diff builders as saying they won't warranty diffs that have synthetic oil in them for that very reason.

 

[zrxkawboy]

Originally Posted By: NineFingerFury
...and JeepKJ.com was to not use synthetic in the diffs.


Sounds like you've been listening to "tjkj2002". The guy's an idiot...the self-proclaimed expert on absolutely everything. He once told how he uses Mobil 1 in his Jeep, and carries a drain pan, oil, and filter in the back so that when he hits 3,000 miles, he can stop and change it wherever he was. Anyone who went more than 3,000 miles on an oil change was abusing their Jeep. When I pointed out that he could run the Mobil 1 longer, and encouraged him to do a UOA, he told how he had seen hundreds of UOAs in the Army, and how I had no clue. OK, whatever....

 

[NineFingerFury]

Originally Posted By: zrxkawboy

Sounds like you've been listening to "tjkj2002". The guy's an idiot...the self-proclaimed expert on absolutely everything. He once told how he uses Mobil 1 in his Jeep, and carries a drain pan, oil, and filter in the back so that when he hits 3,000 miles, he can stop and change it wherever he was. Anyone who went more than 3,000 miles on an oil change was abusing their Jeep. When I pointed out that he could run the Mobil 1 longer, and encouraged him to do a UOA, he told how he had seen hundreds of UOAs in the Army, and how I had no clue. OK, whatever....



Well, after reading more, it appears that synthetics are great, but with the 15k drain interval, it doesn't make much sense.

 

[84zmyfavorite]

I have a Good Friend here in Wenatchee, actually East Wenatchee that has a 2006 Liberty with the 3.7 at roughly the same mileage, and I was wondering if me talking about bobistheoilguy finally got to him, and you were him. His wife has a Tercel, though. Is your Liberty the MidNight Blue?

 

[84zmyfavorite]

Why, I mean Why go 15,000 miles in my opinion. I would recommend a UOA to see where Your 3.7 is at, and fill her up with that PYB(in 5w-30) and spin on that Wix or my favorite, Purolator Classic for a peace of mind 5,000mile OCI.

 

[kschachn]

OK, I'm not easily surprised anymore, but that's a new one. I can't even make up stuff as good as that.

Originally Posted By: NineFingerFury
I heard not to use synthetic in the diffs because it doesn't stick to the gears as well.