ClassA are you changing your oil when the engine is warm?

Heavy fueling will cause the oil to get dark quicker, nothing you can do about it, nothing will be harmed if using the proper oil.

 

a deceased oil man friend of mine told me years ago that oil that did not get darker between changes was not doing its job. it is supposed to keep contaminants in suspension so the filter can get the worst of them and also keep the engine cleaner so when oil is changed they are drained away

 

Wouldn't a good filtration system keep the oil from staying dirty?

 

from what i have read it is difficult to filter carbon with any thing but a centrifuge

 

No. Contrary to popular practice, I drain it when it has sat for the whole day. Believe it or not more oil comes out that way. It is my belief that our oil is not thick enough to retain sediments in the pan which is sloped to the drain anyway.

 

A diesecraft $600 mini centrifuge that is plumbed into the the engine oil line. Bypassed in normal operation, and manually engaged for 10 minutes on every visit to the fuel station (50 gal, 700 miles).

It looks like it will convert your oil into almost like new color.

 

The Frantz Filter on mine keeps the oil very clean. Ten months in to my current change it is still Schaeffer Oil green.

One of the reasons it stays filthy looking is that all of it never gets out of the system. The old oil in the engine mixes with the new oil and turns it darker right out of the gate.

I use this on my motorcycle, watch the video and take a look what he gets out of the 3 1/2 quart system after it has been drained.... The Scavenger TOTAL Oil Change System The way the old oil came out in the video was exactly like mine came out the first time I used it.

A great write up on the Frantz by Gary can be found here. I am sold on these and have one for both my 5.9's.

 

The oil gets dark because of the suspended carbon.

The carbon transfer to the oil in greater amounts is somewhat proportional to your fueling and the amount of smoke produced. The more incomplete combustion you create, the greater the amount of carbon gets transferred to the oil.

The diesel rated oils do have carbon suspension properties. They do not have a limitless amount of suspension properties. You will eventually reach a saturation point and then the carbon begins to act as an abrasive. If you want to maintain a normal engine life expectancy with heavy fueling then I would assume the frequency between oil changes should occur sooner than the normal recommended engine oil changes. This carbon suspension feature and the crankcase capacity is also somewhat proportion to the change intervals. If you decrease the oil pan capacity, such as using the engine in a conversion, then the oil change frequency should become more frequent. That is the reason why our engines and most other diesels hold more than 5 quarts of oil.

Your local auto parts store usually has a shelf full of engine oil flushes. With some you run your engine to the reach the normal operating temperature. You drain the oil and add kerosene and the flush and run the engine in neutral for a few minutes and drain the mix. Then you add the new oil and you are good to go.

 

IMHO if you are relying on draining your oil to "get sludge and (non-soot) sediments" from your oil, then your filter isn't doing its job.