Shell Rotella T Syn 5w40, 4186 Miles, Jeep Cherokee 4.0l

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Sep 17, 2002
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Location
Lakeville, MN
Vehicle: '88 Jeep Cherokee
Engine: 4.0l Inline Six
Tranny: 4 Speed Auto

Oil Filter: Napa Gold 1626 (Wix)
Air Filter: Carquest Premium (Wix)
Oil Used: None
Makeup Oil: None

40%City/60%Freeway Mileage.

Period was from 9/04-1/05 in Minnesota weather.
Average Hi for period: 45 F
Average Low for Period: 28 F
Max Hi: 83 F
Max Low: -12 F

Rot 5w40= Shell Rotella T 5w40 Synthetic
Valv AC 10w30 = Valvoline All Climate 10w30

code:

Oil Rot Rot Rot Valv AC Universal

5w40 5w40 5w40 10w30 Average

Mi on Oil 4186 4192 4103 3515

Mi on Unit69182 64995 60803 52963

Date 1/05 9/04 6/04 10/03

Aluminum 3 2 2 3 4

Chromium 1 0 1 1 1

Iron 39 15 32 17 28

Copper 2 3 3 5 5

Lead 5 8 17 6 5

Tin 1 1 3 0 1

Moly 7 4 6 4 35

Nickel 0 1 1 1 1

Manganese 0 0 1 0 1

Silver 0 0 0 0 0

Titanium 0 0 0 0 0

Potassium 0 1 2 1 2

Boron 0 0 1 1 42

Silicon 10 9 11 9 12

Sodium 9 10 13 15 8

Calcium 3698 3153 2929 1939 2026

Magnesium 10 8 10 10 269

Phosphorous846 897 818 738 770

Zinc 1049 1022 984 890 935

Barium 1 2 1 0 0

TBN 1.3 2.9 2.3 1.9

Vis@100C 11.8 13.3 11.4 8.4

Flashpoint300 345 365 350

Fuel 4.5% 2.3% 1.2% 1.3%

Antifreeze0 0 0 0

Water 0 0 0 0

Insolubles0.5 0.4 0.4 0.4


My comments:

Well, wear is excellent considering the fuel loading
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. The really low flashpoint and major league thinning from around 15 Cst to 11.7 (well into 30weight land)and the TBN drop are all the result of fuel loading.

Despite all that, the Rotella T Syn 5w40 seems to be holding its own in terms of wear. While Iron is high, it also fits in with the very cyclical pattern I get based on outside temps, so that doesn't worry me too much, as that trend has been going on for a while.

So, I'm still working on fuel loading.

To date: I've pulled all the plugs: all are a nice ghost white/tan color with no signs of one (or any) cylinder running rich. Plug wires and distributor all inspected and look fine. Plugs are due for replacement and will be done once its above zero (which won't be until next week).

Techron concentrate was liberally dosed throughout this interval.

CCV system checked and all lines are clear (don't think this is the cause though, as no sign of water dilution in the UOA).

Engine seems to be operating at temp (again, see no moisture buildup), and guage shows running around 190ish, even in -10 F weather.

On ocassion, I get a gassy smell when I shut it off, but it is very intermittant.

ANy thoughts on how to decrease the fuel dilution are welcome, as I don't want to start randomly throwing parts at this problem.

My current guess is a gremlin in the a sensor that causes a intermittant rich condition. Sounds like a blast to track down...
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It may possibly be just your service duty. You've got to be in warm up mode more than the average bear in your climate. Even with not too many short trips, you're taking longer to warm up then most since even a short cool down period sends you back into sub freezing engine temps.

Do you use a block heater?
 
Since your plugs are clean my guess is its the injectors (assuming you have fuel injection). Most leak a drop or two every hour or so after shutdown. Yours are quite old so they might not be closing well and dribbling overnight. They can be removed pretty easily and taken to a shop for cleaning. Look in the phone book for Bosch injector shops. Most injectors are Bosch or a knockoff, or will be compatible.
 
Do a leak down test on your injectors. You can get a fuel pressure gauge and injector from most parts stores. If the injectors are tight, then the computer is telling the injectors to add too much fuel. That will be harder to track down. Probably a sensor in that case.
 
I agree with the comments on the fuel injectors.

A leaky injector would explain both the high fuel contamination and the gasoline smell. You'll definitely want to get it fixed sooner rather than later given the fire hazard.
 
quote:

Originally posted by farrarfan1:
Looks like a tie between the Rotella and the All Climate.

Umm, I'd respectfully disagree, but that would require more information than shown in this post. Most specifically, the one All-Climate interval shown is a summer interval, while any interval with a hint of cold weather using the All-Climate looked terrible (including an iron reading at 55). I've posted all the UOAs I've done on this rig, a search should turn that up.
 
quote:

Originally posted by Gary Allan:
It may possibly be just your service duty. You've got to be in warm up mode more than the average bear in your climate. Even with not too many short trips, you're taking longer to warm up then most since even a short cool down period sends you back into sub freezing engine temps.

Do you use a block heater?


Unfortunately, I don't think service duty is the culprit here. The fuel dilution trend is up since the first UOA I've done, more or less. Diltuion is even a problem in the summer months, so I'm ruling this out.

No block heater. Vehicle was originally my wife's grandfathers and ordered and driven in Colorado until 2002. Having lived on the front range in Fort Collins for five years, I understand why it didn't need a block heater out there! Now that I have it up here, I haven't found a need to install one.
 
Need a little help - how to do a "leak down" test. The three manuals (factory shop manual, Chiltons and Haynes) give zero guidance on proceedure for that. All give guidance on checking the fuel pressure regulator (which checks out fine).

No external fuel leaks at the injectors are visible (and believe me, with the dust/road grime present in those areas, if there was one, I'd know). I definitely do not want a car-b-que, which is an all too frequent occurance on these engines when the injectors leak externally.
 
Do you have a cylinder leakage tester? (this is naturally a stup|d sounding question ..since if you had one ..you would also have the instructions that would tell you what to do ..but
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)

 -


Some just rotate the engine to TDC where the valves are closed. Some go to the trouble of loosening up all the rockers. The supply air is metered/regulated according to the first gauge. The second gauge measures the backpressure (or lack there of) and hence the loss.

If you hear air coming out of the throttle body ..it's an intake ...out the exhaust ..an exhaust valve ..out the breather/oil cap...it's the rings.

This can fool you sometimes. In skewl we performed a leakage test that showed a bad intake on one cylinder and a bad exhaust on another. They were right next to each other. Upon removal of the head it was found that the head gasket between the two cylinders had failed (no water passages). When we tested the one cylinder ..the other cylinders intake was open..when we tested the second ..the first had the exhaust open. If we had lossened all the rockers up before doing it, we would have said that those two cylinders had shot rings.

[ January 17, 2005, 12:24 AM: Message edited by: Gary Allan ]
 
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Gosh ..I do need to have that medication checked
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This isn't a case of dyslexia ...this is metal trans-dyslexia. You transplant words that aren't even there.
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quote:

Originally posted by farrarfan1:
Looks like a tie between the Rotella and the All Climate.
--------------------------------------------------------------------------------

Umm, I'd respectfully disagree, but that would require more information than shown in this post. Most specifically, the one All-Climate interval shown is a summer interval, while any interval with a hint of cold weather using the All-Climate looked terrible (including an iron reading at 55). I've posted all the UOAs I've done on this rig, a search should turn that up.

Sorry. I was comparing the data from the All Climate run dated 10-03 to the Rotella dated 9-04. I assumed these where in at about the same time of the year.
 
I didn't think we we were looking at a leak down cylinder test - I think we were headed to a leak down test on the Fuel injection system.

I did find some guidance on the test in the Chilton's manual.

FWIW, the fuel pressure regulator is operating correctly. Fuel pressure is right on the nuts at 31 psi with vacuum and 39 psi without.

Pressure drops to 25 psi when shutoff, and 5 minutes later, the pressure is down to 20 psi. Chiltons suggests a 30 minute check with 19psi-39 psi being acceptable. I haven't had time to run this yet, but I figure I'll know I have leaking injectors or a bad fuel line check valve. I can isolate the check valve by restricting the inlet fuel line at shutdown.

I'm thinking it may be time to just bite the bullet and order the new injectors from the 5.0 website. (The stock bendix injectors at 18.64...lbs/hr are easily replaced with Ford 19 lb/hour injectors from another manufacturer (likely bosch). This is a pretty common Jeep 4.0l mod to keep costs down (around $35 an injector versus $50 at the parts stores). Call an injector refurbishing shop and they want nothing to do with the OEM bendix units- major league bad leakage problems - external and internal)
 
quote:

around $35 an injector versus $50 at the parts stores). Call an injector refurbishing shop and they want nothing to do with the OEM bendix units- major league bad leakage problems - external and internal)

How much does it cost to have a shop test and flow match a set? Ebay is chuck full of 5.0 square connector #19-#24 injectors for a whole lot less than $35. Would it be worth the costs??
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Leak down test with the rail isolated (return and inlet fuel lines pindhed off) reveals a leak somewhere in the fuel rail and injectors. Funny, I ran the test without isolating the rail a day or two ago, and pressure dropped immediately after shutdown. The same test today and it held pretty well - for about 5 minutes, and then bled off.

Same result after isolating the rail and injectors. Pressure dropped from 32 psi at shut down to 14 psi in a half hour. The test limit is 19 psi.

No visibile leaks or obvious external problems.

All points to a leaky injector (or a few !).

In any event, I'll be ordering up a set of new injectors (I'm sure I could score some cheaper, but I'll sleep better at night with a brand spanking new set in there, and I'll actually get them for about $30 a piece, plus the o-Ring kit for the fuel rail, and the o-ring kits for the quick disconnects.).

Other than an occasional fuel smell, and the oil smelling like it came from an old carbed car in cold weather, no indications of a problem. Not even crank time (as those who have the 4.0 know, especially with the Renix injection, they crank forever anyways!).

Thanks to my UOA's, I'll (hopefully) have solved this one...
 
New injectors are sitting in the garage, no time to replace them yet.
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The joys of selling your place - I guess some people don't enjoy the smell of gasoline vapors! We'll find some time soon to take care of it.
 
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