By Brett Wolfe 1993 U240
We continue to see questions about oil “consumption” and oil on radiators and toads on RV.net and other RV sites. It seems to be universal across all brands of diesel engines.
THE NUMBER ONE CAUSE IS OVERFILLED CRANKCASE. CALIBRATING THE
ENGINE OIL DIPSTICK TO ACHIEVE THE CORRECT OIL LEVEL IN THE PAN “FIXES” OVER 90% OF THESE PROBLEMS.
Step one if you “think” your DP has an oil consumption problem or you are seeing oil mist on your toad (or you just want to verify that yours is correct):
CALIBRATE THE DIPSTICK. Since the same engines/dipsticks are used in many different applications with different angles of installation, do not ASSUME that the dipstick is correctly marked. Calibration costs $0.
At the next oil change, drain oil, remove the old filter (as usual). Then install the drain plug and new oil filter and add the engine’s correct oil capacity LESS THE NUMBER OF QUARTS you want between the “add” and “full” marks (let’s say 2 quarts). So for a C7 with the 19-quart capacity, you would add 17 quarts. Run the engine a few minutes, shut off and wait until the oil has descended into the pan (at least 30 minutes and an hour is safer). Pull the dipstick and use a file or Dremel tool to mark the oil level “add”. Add the remaining two quarts, let the oil settle in the pan, pull the dipstick and mark this the “full” mark.
In many/most cases, you will find that your engine “throws out” the access oil and then “consumption” settles down to next to nothing. Put in the correct amount and your “consumption” issues may go away.
This applies to all ages (including brand new) of motorhomes and boats with every brand of engine.
Also, when checking the oil level with the dipstick it is safest to do it in the morning after the oil has had all night to flow back to the pan.
Do not add oil until the level reaches the ADD mark.
Finally, make a sticker to affix near oil fill: OIL CAPACITY INCLUDING FILTER: xx QUARTS.