99 Jeep Wrangler 2.5L GC 0w30

[wn1998]

Motor: 1999 Jeep Wrangler 2.5L
Mods: (4.0 Throttle body, throttle body spacer, Dynomax catback exhaust)
Engine miles: 46,000 Oil
miles on oil: 5,136
Sump size: 4 quarts
Filter type: Napa Gold Oversized 1515
Oil type: Castrol Syntec ow30 (GC)
Make-up: 0
Length of service: 4 months

Use condition & weather: Added GC for first synthetic run after an ARX cleaning in December and ran it til April.

Comments: I ran this oil with an initial dose of LC of 6oz and added 2oz every 1,000 miles. I also rand Fuel Power about 5-10 times during this OCI. ( I would have run it more but Chicago winters are too cold to be adding FP to the gas tank!)


Analysis by Blackstone


Aluminum: 2
Chromium: 2
Iron: 45
Copper: 6
Lead:3
Tin: 0
Moly: 30
Nickel: 2
Manganese:1
Silver: 0
Titanium:0
Potassium:1
Boron: 9
Silicon:12
Sodium: 5
Calcium: 2303
Magnesium: 92
Phosphorus: 601
Zinc: 774
Barium: 0

Properties: As tested
Sus Visc 210*F: 61.3
Flashpoint *F: 370
Fuel %: .8
Antifreeze %: 0
Water %: 0
Insolubles %: .4
TBN:2.9

 

[TR3-2001SE]

Iron and Chrome look a little high. You are probably cleaning out your engine. Oil and LC,FP is a great combo. Great report! I would not change a thing!

 

[Gary Allan]

This is typical Fe for this engine. They're always high. If you wish to reduce it, use a 40 weight. 5w-40 T&SUV is cheaper, more available, and has a much higher TBN. It would probably last double the mileage/months. If you don't mind the high Fe ..stay with the GC.

Due to your mileage/months, you can't have a bunch of cold starts. You've got to be commuting a good 50-70 miles a day ..or you have one heck of a trip every weekend.

Your fuel needs to get below .5% and your insolubles appear on the high side.

I'm unsure with FP, but I'd do a couple of shock dose additions to the tank to assure that the injectors are clean.

 

[Ryan00TJ]

Report looks pretty good. I've noticed that if you stick with an oil for 2-3 changes the wear numbers drop, switch to try out another oil and they go back up. If you use GC again next time the wear should be better.

Gary is right about this motor and the 4.0L throwing out lots of iron in UOA's. I ran my TJ on straight 15W-40 last summer and it did great. Thicker oils tend to drop the iron levels in these motors.

Here are my UOA's on my 2.5L you can compare to..... http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002310#000000

 

[Geoff]

Is the iron from cylinder or valve train wear? Do these engines have roller cams?

 

[Ryan00TJ]

I don't think so. Just regular Hydraulic Flat tappet design.

 

[Gary Allan]

quote:

---

Is the iron from cylinder or valve train wear?

---

Cylinder wear. This engine is a throwback. Long stroke, heavy, no crossflow head, high torque, limited hp potential, and not a fuel squeezer. Boring, but extremely reliable.

 

[Greaser]

I read somewhere that the timing chain,due to it's oil bath with the rest of the crank oil,contributes to the high iron. Using a 40W oil seems to ease the iron in this engine.This is almost a moot issue anyways...thousands (millions?) of the Jeep 4.0's are out there being maintained with minimal care and running 200,000 miles plus easily....and they are flat tappet lifters.

 

[Gary Allan]

Thanks Greaser. The timing chain isn't something that I'm aware of ..and may well be a major contributor to the higher Fe #. I lean toward cylinder wear due to, as I said in the past, the issues that I've seen with blow-by. But this could easily be more perception than substance. It may be more along the lines of the DC minivan transmissions. With millions in service ..if you only see the broken or ailing ones ..it's going to be many .. giving you the impression that it is a high percentage (a point I tried to make about Warner filters).

[ May 15, 2005, 03:42 PM: Message edited by: Gary Allan ]

 

[MarkC]

The iron wear levels from my 4.0 are pretty fine with a 10W30; 14 ppm for a 3K OCI, which comes out about 4.6/K.

 

[1maniac]

Isn't this the 2.5 4 cylinder?

 

[Gary Allan]

Same basic design ..just two cylinders eliminated from the casting. Same rods, same pushrods, same rockers, valves, etc. They just saw cause to hack one of the cylinders that would have allowed cross use of all the other drivetrain components. The 4.0 has a two piece rear main ..the 2.5 has a 1 piece. Differnt bolt pattern. The 2.5 shares the GM V6 pattern and can use any trans that the 2.8 bellhousing will bolt up to. You can't directly swap anything between a 2.5 and a 4.0 drivetrain.. except maybe the t-cases for the automatics. I believe they share the same input depth and spine count. Otherwise the AX-5 and AX-15 have different stubs (in both length and spline count) and consequently the 231 tcase has different input components. The 2.5 had a better head flow design ..so the 4.2 was altered in this respect to copy it in the 4.0. This is why a 4.0 head conversion is so popular for those who have CJ's. Much better breathing.


btw- for anyone doing a refit on either of these engines, SBC rods fit the crank jounals of jeep crank. This gives you lots of options for quench adjustment using various pistons available. 305 rods and pistons are a popular swap. It gives you a longer rod and provides better torque.

 

[unDummy]

If you're a Castrol fan, then definitely give the syntec 5w40 a try!

I wonder if the 51773 will fit in place of the 51515 for a little more oil capacity.

And, if you must stick with the 0w30, try a run without the LC to see how the numbers compare with it!

 

[Ryan00TJ]

I only am able to run a 51773 filter due to a remote mount in the engine compartment. I've tried one on my brother's 98 TJ 4.0 and it's too close to the frame for my liking. I just stick with the FL1A's on his.