Jeep 4.0 PYB 10w30 UOA

[jeepman3071]

This was a run of Pennzoil Yellow Bottle 10w30 in my 2000 Jeep Cherokee 4.0L with 140,000 miles at time of sample. The OCI was 4,000 miles. This Jeep sees mostly short trips with the occasional highway drive. Make-up oil was 1/2 quart of PYB 10w30 due to a rear main seal leak.

I'm very impressed with the iron numbers!

BlackStone Comments:

"JOSH: Thanks for the reminder on the rear main seal leak and the make-up oil you're adding. It might serve
to dilute metals a little, but that's not a problem. And if anything, with the oil you're adding, it might help you
run a little longer between oil changes. The viscosity was a little low in this sample, (but it was about the
same as last time, so that's not an issue). Wear metals are surprisingly good. Iron is much lower than it was
last time, but that's no problem at all. The TBN is still good at 2.7, so you should be fine with a longer run
next time. Try up to 6,000 miles."

Code:
OIL PYB 5w30 PYB 10w30 Universal Averages

MILES IN USE 3,503 4,000 4,300

MILES 131,203 140,000

SAMPLE TAKEN 3/2/13 12/13/13



ALUMINUM 3 3 3

CHROMIUM 1 0 1

IRON 23 9 27

COPPER 2 2 4

LEAD 1 0 3

TIN 0 0 1

MOLYBDENUM 258 242 67

NICKEL 1 0 1

MANGANESE 0 0 1

SILVER 0 0 0

TITANIUM 0 0 0

POTASSIUM 1 1 3

BORON 89 73 45

SILICON 11 7 11

SODIUM 10 6 35

CALCIUM 2419 2273 2100

MAGNESIUM 18 7 124

PHOSPHORUS 787 709 723

ZINC 914 786 868

BARIUM 0 0 0





Values should be

INSOLUBLES 0.3 0.2
WATER 0 0
FLASHPOINT ºF 410 415 >365

SUS VIS 210ºF 56.2 56.6 59-68

cSt @ 212ºF 9.11 9.25 9.9-12.7

Fuel
Antifreeze 0 0 0

TBN 2.6 2.7 >1.0




I've been pretty happy with the PYB in this engine. I run it in two other 4.0 engines in friends' Jeeps. It is the quietest oil I have found.

 

[gregk24]

Seems like you hit the sweet spot with PYB 10w30.

 

[Donald]

Looks good to me. Whats your plan for the leaking seal?

 

[Chris142]

Mine was leaking and it looked like it was the rear main but it was just the oil pan bolts next to the cats.

 

[901Memphis]

Almost proof that 10w30 is a phenomenon in the Jeep engine.

Moly is high though are you using additives?

 

[Kuato]

That is the lowest iron I have seen on the 4.0...something to 10w30 in this engine for sure.

 

[901Memphis]

Do you have any magnets in the system? Like a filter mag?

 

[Garak]

Originally Posted By: 901Memphis
Moly is high though are you using additives?

I believe that's normal for SN/GF-5 PYB, at least according to the last few VOAs I've seen.

 

[CharBaby]

Originally Posted By: Donald
Looks good to me. Whats your plan for the leaking seal?

+1
How about Pennzoil HM 10W30?
OR, DEFY 10W30?

 

[jeepman3071]

I plan on replacing the seal this summer. I believe its either a rear main seal or the oil filter adapter o-rings, but I will know once I start working on it. I've been too busy with classes and work lately.

I'm not using any additives or a filter magnet, although I would like to use a filter magnet sometime in the future.

 

[KCJeep]

Wow just wow that may be the best 4.0 UOA I've ever seen, at least currently anyway! PYB for the win!

Your 4.0 wears better than mine but it has higher miles too.

I was really curious to see if the 10w30 would resist shear better than the 5w30 PYB but it appears the difference is not real significant, although it was still a smidge higher and went an extra 500 miles. So a difference, but not much.

I think your steady use of PYB may have helped, all that constant moly has eventually yielded you a phenominal iron number. I'm a big fan of PYB SN in the 4.0 and would probably run it exclusively if not for a stash to get through...one of the downsides of a stash.

 

[jeepman3071]

Originally Posted By: KCJeep
Wow just wow that may be the best 4.0 UOA I've ever seen, at least currently anyway! PYB for the win!

Your 4.0 wears better than mine but it has higher miles too.

I was really curious to see if the 10w30 would resist shear better than the 5w30 PYB but it appears the difference is not real significant, although it was still a smidge higher and went an extra 500 miles. So a difference, but not much.

I think your steady use of PYB may have helped, all that constant moly has eventually yielded you a phenominal iron number. I'm a big fan of PYB SN in the 4.0 and would probably run it exclusively if not for a stash to get through...one of the downsides of a stash.

I was surprised as well with the shear, but the TBN was a bit higher on this sample and I ran it for 500 more miles so that is definitely a good thing.

I would like to do some UOAs on the other Jeep 4.0s that I service, and compare them to these results.

 

[SwampSurvivor]

Wow! That's some low iron for a 4.0!

I want to get the PYB in mine pretty soon! I will try to pull a UOA of the RT6 when I drain it.

Also looks like piston skirt failure is not in your future - which is good, of course.

 

[jeepman3071]

Originally Posted By: Miller88
Wow! That's some low iron for a 4.0!

I want to get the PYB in mine pretty soon! I will try to pull a UOA of the RT6 when I drain it.

Also looks like piston skirt failure is not in your future - which is good, of course.


Don't jinx it haha.

 

[SwampSurvivor]

That's why I am afraid to pull a UOA on mine!

 

[dlundblad]

Looks great. I can't wait to send mine in next month. I just hope the few -15*F starts didn't mess with my iron wear.

 

[KCJeep]

I just messed a little with the viscosity calculator. The 1/2 quart top off of 10w30 would be enough to boost the 5w30's kv@100 from 9.11 to 9.23. Since you ended up with 9.26 on the 10w30 to which you added half a quart, my conclusion is there is no real shear resistance advantage to the 10w30 over the 5w30 with PYB, at least not in this engine.

The 10w30 still has a little bit higher HTHS though. I believe next winter I'll just go ahead and run the 5w30 again, and be sure not to run it too long, 3k maybe.