Rotella 15/40

Bought a diesel Waukesha. Previous owner said it has bad blowby. Said he ran rotella 15/40. Think it's worth trying a different brand? Pulled the valve cover and it's pretty slimmy up there.

So what's the rest of the story? Where's your backup that there is something wrong with Rot T? Some of us have used it as primary diesel
oil for 35 years and still using it. Want to hear the rest of our stories?

Well, you don't say what it is in, but if its an Oliver, the last one was made in about '73 or '74. Any chance its just plain worn out?

Yep. It's a 74 232 and probably needs rebuilt. I have never used rotella so I'm just curious what everyone thinks about it. Bought it as a running core. Don't really Care if it performs as I will not use it much. Think I will get it fired up and go from there.

I buy what ever is cheapest on sale at fleet farm for 15-40 oil. Usually it is their own branded pails, but occasionally with rebates it is Rotella.
I've never had any concerns with any oil brand myself. I don't think it makes any difference in these 50-80 year old tractors. All brands have
better oil now than they ever did when these tractors were built. Just my opinion though.

I had an injector put in my 9620T a year ago, the mechanic said it was the cleanest he had ever seen in an engine. He asked what I was using, 15/40 Rotella is all I run in it.

I have used Rotella 15w40 oil for several years in Olivers, Whites, Deutz-Allis (Deutz engines) and CUMMINS on my Gleaner Combine, never
had a problem related to oil .

Put a good thermostat in it and work it hard, maybe it will clean up.

Change it, and add a couple bottles of Lucas,it might help, and it sure wont hurt anything.

thank you for the replies. Good to here good comments. Most run delo around here.
Somewhere I read someone had a blowby problem and solved it by switching oil. Probably was a coincidence.

While Rottela is not the absolute best oil out there. It is certainly acceptable in quality, protection, availability and price.

The 310 in our 1855 world burn more oil with Rotella than with Mobil Delvac. Both were fine oils, but once we used the Mobil it's oil consumption went down a fair amount.

Donovan from Wisconsin

I worked for a freight line for 38 years and all they used was 15-40 Rotella. They had a fleet of 60 trucks powered with Detroit, Cat, IH,
Cummins,And some GM and Ford gas engines. We also used it in Allis Chalmer and Cat fork lifts with no problems.

I don't believe it's as much of an issue with the oil as it is the service interval. If it's slimy up top the rest of the engine has suffered as well. The rings may be sticking. I would change oil and work it and also check the oil pressure when hot and idling. If it starts to clear up I would do another oil change in a month and work it some more. The rings may be sticking.

I have never - ever - had a detergency issue with Rotella T. I've seen the insides of engines with 500,000 miles that ran on
it and we super clean inside.

One odd thing. My 1988 Toyota motorhome with a 2.4 liter four-banger was using a 1/2 quart of oil every four tanks of gas.
That was with Shell Rotella T 15W-40 . I changed to Mobil 1 High Mileage 10W-30 and it now uses no oil. Hard to figure why.

You may have got the same result by going to Shell Rotella T 10W-30.

that is other problems , not the oils fault.

I had never used the Shell Rotella oil until I purchased my 2002 Chevrolet 2500HD with the Duramax diesel engine. The prior owner had used nothing but that engine oil in that truck. A few others I have known to use this oil had nothing but praise for it. I continued to use the 15W-40 until just three years ago. I switched it over to the 5W-40 synthetic Rotella because the truck is generally parked in the winter months, but I may need to use it when we have lots of snow in the winter months. Under those circumstances, and especially when it gets quite cold, I want to make I have the best chance of the truck starting. Never had an issue before, but I would plug in the block heater before starting, too. Anyway, one thing I have noticed with the Rotella in that truck, the engine oil keeps its brown color and remains relatively clear all through an oil change. I suspect part of that can be attributed to the low sulfur fuels and a good, tight engine. The truck only has 76,000 miles on the odometer, and I am satisfied with what I have seen. My dad's 2004 Dodge Cummins turns the oil black in a hurry, and he made the switch to the full synthetic Rotella just a couple years ago, too. He seems satisfied with using that oil. As an aside, I did get hooked on Mobil Delvac back in the 1980's when I had a GM 5.7 liter diesel engine that was using a lot of engine oil. In a matter of 3 oil changes and some particular type of driving, I took the oil consumption from 1 quart to 300 miles down to 1 quart to 1500 miles. I attributed the oil consumption to stuck rings in that car. I do believe Delvac also is a good quality oil, too.

Yes, no magic claimed with the so-called "synthetic" Mobil 1 High Mileage. I just chose it because of it very high ZDDP content. Other oils may work just as well.