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Found a cure for 3.5 oil burning! Rotella 15w-40

50K views 77 replies 34 participants last post by  bullet07104 
#1 ·
BEFORE I TELL YOU - Dont go harassing me saying "it aint possible, its just a fluke, you're crazy, you aint no good at checkin oil, etc"

Background - I got a zillion miles on my Troop. '98, 3.5. Its burned oil for years...actually for 6 years. Last few years has been 1qt/400 miles. Didnt seem to affect the vehicle at all - ran super duper.

What I have tried as far as fixing the oil burning?
1. Auto RX clean/rinse 4 times - 2000 mile clean, 2000 mile rinse. 4 times.
2. Seafoam - 1/4 can in the crankcase. 1/2 can in the crankcase, full can in the crankcase - You name it, ive donr it. Hell, Ive run a full can for 300 miles before draining.
3. Cylinder soaks.
4. New EGR, cleaned EGR tube, New PCV
5. Mobil 1 5w-20, 5-30, 10-30, tried 'em all!

Ive done it all over the years. Nothing cured the oil burn. I quit trying to fix the burning about a year ago. I just said the heck with it and bought a case of Walmart oil on sale and put it out of my mind.
--------------------------------------

So I was browsing Bob is the oil guy.com the other day.... ran across some deeply-buried post from a 1999 trooper owner who said he cured his oil burning by using Shell Rotella 15w-40 diesel truck oil.

Of course I thought Bull-****, it wont work. We need a thinner oil to get through our clogged drainback holes!

But I decided to try it anyways. Just to prove him wrong I guess.

I cant F-ing believe it. You dont F-ing believe it either Im sure, but my oil level has not dropped even a millimeter in over 1000 miles! :shock:

Please.... someone else try it. It cant be this simple.
 
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#2 ·
Its beleivable with the 3.5. I've read on another forum where the cyclinders were over bored on some of the 3.5's making the gap between the piston and cylinder too wide. Thicker oil will help reduce the burning in that situation.

With the 3.2's the problem is the size and number of drain back holes (was changed with 3.5, they have larger and alot more of them) which restricts the flow of oil back from the rings and causes it to burn off. Thus the need for thinner oil so it can drain back easier.
 
#3 ·
the early 3.5 was the problem motor, the 1998 and 1999 motors are the serious burners. The 2000-up 3.5's has twice the number of drain holes.

the 3.2 does burn oil, but not as bad as the 98/99 3.5's

Its so bad, that the number of 98/99 tropers you see on the road are nill. Many, many have blown up. We are talking about motors with 50k miles burning 1 quart every 200 miles!
 
#5 ·
Rotella is Good Stuff. After seeing some testimonials about running it in motorcycles I've been using it in my bikes. It's compatible with the bikes' wet clutches and doesn't have the 'polymer shear' clutch-slippage issues that can be caused by using "energy efficient" oils with a lot of viscosity extenders.

I've also been running dino 15W-40 in my Spacecab, and Rotella Synthetic in the 3.4 LS.

If your local Wal-Mart carries it, you may find a darn good deal there. I expect Delo in the same viscosity would work as well. BTW Castrol is also marketing a 15W-40 GTX diesel-rated oil, and my Wally's carries it.

Cheers...........ed
 
#7 ·
What the hell, why not. What, I'm going to burn more oil?

I am completely in the "just got used to burning oil" camp. I have qt in the back storage area, and generally carry 3-4 quarts when I go on road trips.

Yes, there are a ton of 98 -99 Troopies around, all with blown motors. I am trying to find one with a leather interior that I coould swap into mine.
 
#9 ·
So I've read some places that the number of drain back holes changed in mid-2001, and some places that it was mid-2000. Does anyone know for sure? If you have a 2000 model year Trooper with the original motor and the "screw-in" type PCV valve, can you post the production date?
 
#10 ·
Yes, I need to change my sig. line. Im up to 1200 miles, no oil burned. I swear I must have gas leaking into the crankcase keeping it at a high level. I still dont believe it - :wink:

Somebody asked if the Auto RX may have cured it..... no dice.

But I do reccomend the auto RX anyways. It really did give me a noticeable increase in "seat of the pants" measured HP. I certainly wasnt expecting that. I kept looking for oil consumption to decrease. Never happened. But every day the motor kept feeling stronger and smoother.

The Auto RX did NOT make it quieter (valvetrain makes more noise now) but it is undeniably more powerful and smoother. I dont feel its underpowered at all anymore. Lately (last few years) its been struggling on hills. Now it really has more punch.
 
#11 ·
Since the '98+ Troop and Rodeo have a "Direct Attack" valvetrain, I would not expect Auto-RX to be of much help there. The only real cure for valve noise on those motors should be a proper valve adjustment. Isuzu's recommendation for the service interval on that is "when it gets noisy".
 
#12 ·
Sounds pretty tempting. Is the Rotella you're using synthetic? My trooper runs great at 158K miles but oil consumption continues to increase, averaging 1 qt every 750 miles.

Would switching from synthetic present any adverse issues?
 
#14 ·
pkgdave said:
BEFORE I TELL YOU - Dont go harassing me saying "it aint possible, its just a fluke, you're crazy, you aint no good at checkin oil, etc"

Background - I got a zillion miles on my Troop. '98, 3.5. Its burned oil for years...actually for 6 years. Last few years has been 1qt/400 miles. Didnt seem to affect the vehicle at all - ran super duper.

What I have tried as far as fixing the oil burning?
1. Auto RX clean/rinse 4 times - 2000 mile clean, 2000 mile rinse. 4 times.
2. Seafoam - 1/4 can in the crankcase. 1/2 can in the crankcase, full can in the crankcase - You name it, ive donr it. Hell, Ive run a full can for 300 miles before draining.
3. Cylinder soaks.
4. New EGR, cleaned EGR tube, New PCV
5. Mobil 1 5w-20, 5-30, 10-30, tried 'em all!

Ive done it all over the years. Nothing cured the oil burn. I quit trying to fix the burning about a year ago. I just said the heck with it and bought a case of Walmart oil on sale and put it out of my mind.
--------------------------------------

So I was browsing Bob is the oil guy.com the other day.... ran across some deeply-buried post from a 1999 trooper owner who said he cured his oil burning by using Shell Rotella 15w-40 diesel truck oil.

Of course I thought Bull-s__t, it wont work. We need a thinner oil to get through our clogged drainback holes!

But I decided to try it anyways. Just to prove him wrong I guess.

I cant F-ing believe it. You dont F-ing believe it either Im sure, but my oil level has not dropped even a millimeter in over 1000 miles! :shock:

Please.... someone else try it. It cant be this simple.
pkgdave. Could you please tell me the API specificatio of Rotella oil that you used? is the oil Rotella T 15W-40? Even better could you post a image of the label found in the can?

Thanks,
 
#15 ·
ha. Interesting. My 04 3.2 had some serious burning issues as well. I have less than 10,000 miles on it, believe it or not and was going through 1 qt every 500-700 miles roughly. (tried synthetic + non). Since I drive 300-400 miles/week on the freeway at 80+mph that consumption was a obnoxious!!!

I switched to AmsOil Synthetic 20W-50 1,300 miles ago and a drop has not been consumed. Its some expensive *** oil though, I can tell you that much
 
#17 ·
Did you say 4 Gallon or mean to say 4 quart? 4 Gallon would be one very big jug. Big jugs....I like 'em.
 
#18 ·
I bet the Rotella has the same spec as the Mobil 1 Truck and SUV oil.

Diesel oil, I believe, has extra cleaners in it to help with extra soot.
I am guessing it is just like running a can of Seafoam in with the oil.
 
#20 ·
Zaphod said:
timrkopi said:
I bet the Rotella has the same spec as the Mobil 1 Truck and SUV oil.
Well, if that's true, then I'm screwed. Mobil 1 did nothing to help my oil-burn problem. :?
Likewise. But as I said, AmsOil so far has cured my issue. I think they make some of the best products out there.

In addition to using it in the Rodeo there is a known issue with the manual IS300s that have had their transmission fluid switched out @ the 30K service (performed @ 26,000 miles, currently at 32,800 miles). With the oil the dealer puts in (slightly different from the original break in tranny oil) the car is hard to shift from 1st-2nd when its cold out. AmsOil makes the only gear lube that has been able to cure this problem.

It has cured 2 out of 2 problems that I've had (one in each car) :) I highly suggest it.
 
#21 ·
I said Mobil 1 Turck and SUV. NOT regular Mobil 1.

Mobil 1 Truck and SUV is relabled Mobil Delvac 1. Some say
slightly reformulated.

Delvac is Mobils truck oil. Delvac 1 is the synthetic version.
 
#22 ·
So, what harm would come from throwing Shell Rotella 15w-40 diesel truck oil in my 97 3.2 Rodeo? Blow a gasket?

I've been dumping gas station brand oil in (10W-30 in the winter, 10W-40 in the summer), 1 qt every other tankfull to keep it on the stick. An oil change every now and then when I think of it.

I have 158,000 miles on it now, and drive it 100 miles a day, mostly highway.

IMRR??
 
#23 ·
I am guessing it is just like running a can of Seafoam in with the oil.
The antioxidants and soot control is in the form of calcium and magnesium in oil, diesel oils have a more "robust" package of calcium and magnesium. Seafoam is a very lightweight oil-based substance that has been proccessed to the point of being near karosene. It contains no antioxidants that I am aware of, and should not be considered a replacement for the addatives in oil at all. It reduces the concentrations of proper oxidation control in oil, and thins oil viscosity.
 
#24 ·
timrkopi said:
I said Mobil 1 Turck and SUV. NOT regular Mobil 1.
Ah! Sorry! Didn't pick up on the difference! :oops:

Hell, I didn't know such a thing existed! :shock:

So..... Now I have THREE new options to try! AWSOME! :D
 
#25 ·
mdocod said:
Seafoam is a very lightweight oil-based substance that has been proccessed to the point of being near karosene. It contains no antioxidants that I am aware of, and should not be considered a replacement for the addatives in oil at all. It reduces the concentrations of proper oxidation control in oil, and thins oil viscosity.
I use it in the gas tank in lieu of Gas Treatment. Don't know if I'm burning $5 for nothing every time I do that.

I do use it in the crankcase right before changing the oil so as to wash out the ol' belly, especially if I've had some time between changes or if I ran it low for an extended duration.
 
#26 ·
I use it in the gas tank in lieu of Gas Treatment. Don't know if I'm burning $5 for nothing every time I do that.
I've always wondered what do you use when you really need to clean something that's dirty. A bit of gas on a rag will clean just about anything.

I can't think of anything shy of turpintine that cleans better. So what could possibly be in your fuel system that needs something more powerful than gas to get it out or dissolve it. Only thing I can see to clog an injector is a piece of grit or something that has gotten past the filter.

There's no fluid that will get that out.

Just my opinion.

Stepping off my soapbox now, don't get me started on 93 octane gas (the "good" stuff) either. People that run it to give it the good stuff are wasting their money.

Joe
 
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