10W30 Mobil 1 TriSyn SL in Jeep 4.0L

[JonC]

This is my first oil analysis for my '99 Jeep Wrangler with the 4.0L six. I've used Mobil 1 10W30 in it since the first few thousand miles. I've used mostly Mobil 1 filters.

Blackstone expressed concern about a possible antifreeze leak due to elevated salts. Since I've never had to add any antifreeze, I doubt there is a problem. I think there may have been contamination of the sample due to the plethora of salt use on Chicago area roads - it would not surprise me if there was salt around the drain plug.

The iron seems a little high. I wonder if this could be due to the cold, January weather.

Any observations would be welcome.

Oil: 10W30 Mobil 1 TriSyn SL
Filter: Mobil 1 M1-204
Mileage on oil: 3,393 miles
Mileage on vehicle: 65,000 miles
Engine: 4.0L inline 6 cylinder

Aluminum 4
Chromium 1
iron 44
Copper 3
Lead 7
Tin 1
Moly 73
Nickel 1
Manganese 1
Silver 0
Titanium 0
Potassium 61
Boron 119
Silicon 12
Sodium 33
Calcium 2678
Magnesium 35
Phosphorous 767
Zinc 833
Barium 0

Viscosity 59.4
flashpoint 315
Fuel % 2.5
Water % 0
Insolubles 0.3

 

[Ryan00TJ]

What type of driving conditions does your TJ normally see? Unless that is a lab error 2.5% fuel dilution is pretty high. It could be the cause of the high iron but since the other wear metals are fine I doubt the fuel in the oil is the cause. Flashpoint seems low at 315. Oil is a solid 30W. Silicon of 12ppm shows your air filter is working fine and doing it's job. I'm glad to finally see a SL TriSYN UOA as it looks very much like the new SuperSyn formula, Moly 73 ppm and the low Magnesium just like SuperSyn. Due to the lack of 4.0 UOA's we can't be for certain why the iron is at 44ppm. Some engines create very high wear numbers while some hardly any but that doesn't mean the higher number engine can't last 200,000+ miles.

 

[Al]

Yea-you have the SuperSyn. It is probably due to a mismarked bottle. Mobil bottles were out of control during the change to the SL TrySyn and then the SuperSyn. The lables couldn't keep up. Looks like you do a lot of short trips. Thats killing your iron (considering the fuel dilution and cold weather). I also doubt you have a radiator leak. I believe some of that sodium is the anti-foam. You probably need to get that puppy heated up a little more. Thanks for posting.

 

[MNgopher]

I had a UOA on my Jeep Cherokee Using Valvoline All Climate. It has the 4.0l, and yes its an '88, but the motor hasn't changed very much over the years (besides engine controls). Here is a paste of that post:

Customer Name :
Oil Brand/Weight : Valvoline 10w30
Type Equipment : Jeep Cherokee
Miles/Hours on oil : 3553
Total Miles/Hours : 45993

Results ppm/% Comments (blank=normal)
Wear
Copper 2
Iron 51 dirt causing wear,from air intake or filter
Chromium 1
Lead 3
Aluminum 5
Silicon 22 check air filter
Tin 3

Additives
Molybdenum 5
Sodium 30
Magnesium 52
Zinc 780
Potassium 0
Phosphorus 675
Calcium 1380

Physical Properties
Water negative
Fuel negative scale negative,trace,positive
Antifreeze negative
Soot 23 some solids present
Oxidation 65 scale 0-199 33%
Nitration 81 scale 0-199 40.50% elevated, need tune up
Sulfur 87 fuel sulfur
TBN 9
Vis@100 C 9.4 low 30w


You can see I had high Iron also, most likely due to the air filter not sealing well and elevating my silicon levels.

I also had a high sodium measurement at 33. No traces of antifreeze in other elements or tests. My theory (for the moment anyways) is also road salt usuage either via the air intake or from around the drain plug during sampling. I haven't found any other explanation!

From the UOA's I've seen on this engine, the 4.0l seems to generate higher Iron numbers than many more current engine designs. Since it basically runs like a tractor motor and these things run forever, I wouldn't be worried until a trend is identified.

 

[JonC]

I've owned 4 Jeeps with the 4.0L engine, and I think it is a very tight engine. It seems to get smoother and "freer" as the miles build up - I've commented that it takes 100,000 miles to break in the 4.0L engine.

I have about a 20 mile commute to work, but I occasionally drive a couple blocks across our plant site. I'm sure that short drive combined with the cold weather doesn't help the fuel dilution.

I will resample in the summer and see what I get. I may also switch to a Wix filter and see if the lower filtration, but higher flow helps to reduce the iron. Then again, that may just be a trait of this engine.

Thanks for the comments.

Jon