Oil pressure and Percent load

[Guy Pryor]

I have an ISL Cummins 370 HP in a 2003 beaver Contessa. When climbing an upgrade I try to keep the percent load at or below 100 percent
But sometimes on a long  upgrade to keep from slowing down too much I push a little harder on the throttle and the coach doesn't seem to mind it just climes the hill with the best. But after a long hill climb at 100 percent load I find that oil has been spayed all over the rear bumper and the toad. From what looks like an oil overflow tube from the  side of the engine. So do I need to just keep it under 100 percent load or is my oil over filled or what. 
Thanks

[David T. Richelderfer]

On these long uphill climbs at 100/100+ percent load, what temperatures do your engine and transmission show at their highpoints?

[Gerald Farris]

Guy,
There is no simple answer to your question. However, with a little more information, we can narrow down the possibilities, especially since it looks like you are showing a picture of the crankcase breather hose where you apparently think the source is. First, have you calibrated your crankcase dipstick, or are just filling the engine oil according to the factory marks on your dipstick? Next, have you checked and/or cleaned the crankcase breather system and/or screen? Next, what RPMs are you running at when this happens? Last, like David said, what are the engine and transmission temperatures when this happens?

Gerald

[Guy Pryor]

The engine and transmission temps both stayed in the normal range about 175 to 180.  I had my last oil change at the freightliner service center and When I checked the oil afterwards I noticed that the old full and add marks had been ground off and new ones added I would assume that is the re calibrated dip stick. I don't know if the breather system was checked or cleaned at that time. I am not Sure what RPM,s I was running but I was in 6th gear running about 50 MPH so RPM,s were not to high. I am due for another oil and lube soon and I will be asking them about the Breather system.

[Gerald Farris]

Guy,
You may be overfilled with oil. At your next oil change, be sure that the technician adds the proper amount of oil (after draining the oil) less one gallon. Then crank the engine and idle it for a minute or so before turning it off. Let it set for about 5 minutes, then check the oil level on the dip stick, that is where the add mark should be. Next add one gallon, and check the oil level on the dip stick, that is where the full mark should be. Never assume that all technicians add the correct amount of oil. I have seen oil changes leave a shop with no oil in the engine to have double the correct amount, and since large diesel engines may have different oil pans depending on application, correct oil volume is sometimes confusing, especially to the inexperienced techs that usually draw oil changes. I never gave oil changes to my best techs, it was a waste of a badly needed resource that was hard to find.

Gerald   

[Stan Simpson]

Gerald,
My oldest son is a diesel mechanic for 30 years. He does my PMs on the coach. The owner's manual says the correct amount of oil is 37 quarts. Neither of us have ever calibrated the dip stick as you describe. When he drains the oil, he refills it with 37 quarts as per the manual. I have never seen the symptoms described by Guy. Wouldn't Monaco know the correct amount of oil required? Do you think the way we are doing it is okay?
Stan

[steve zannella]

Guy
Another thought on this could be diesel fuel. This may or may not be related to your issue but I get oil spots on my toad after a long 7% climb at 99 percent load, such as US 395 north from California to Nevada, I have noticed what looks like unburnt diesel fuel sprayed on the passenger side of my toad which is the exhaust pipe side. It appears that the diesel spots turn black from road dust. There is no other explanation for it. So far I have only noticed it happening on that stretch of road.

[Gerald Farris]

Stan,
The way that you are changing the oil is OK. The only reason that I described the procedure above is to let Guy know how to correctly calibrate his dipstick. The dipstick on most coaches is not accurate. The coach manufacturer usually adds a flexible section to the dipstick tube to make it fit their application, and they were not real precise in keeping the dipstick tube the correct length. Since the tube length varies between many coaches even though they have the same engine, the dipsticks are not correctly marked. Therefore, you can not tell if you have the correct amount of oil with the dipstick until you calibrate the dipstick. Dipstick calibration only needs to be done once in the life of the coach if it is done correctly unless the dipstick tube is altered.

Gerald

[Dave Atherton]

Gentleman ,
I would like to add a few thoughts on this very good subject with very good inputs already. The correct amount of oil in today’s electronic engines is extremely important.  With overfilling, older engines have a breather tube that vents moisture to the outside on both Caterpillar and Cummins engines. What you see in your car is oil droplets mixed with moisture vapors. Many of member do have the external engine vent tube. In your diesel over filling oil can cause the engine atmosphere pressure sensor to sense what is happening inside the crankcase while running, trip the light on dash and will derate power as atmosphere pressure sensor gets plugged. If the engine vent tube has a valve connected to the vent tube that if not serviced,  pressure  build up inside crankcase will reduce venting through breather tube and will vent through dip stick tube and in extreme cases through the rear engine crankshaft seal or front crank shaft seal. Lastly, remember when you change oil and fill to full mark on the stick, oil warms up and will expands, raising the oil level on dip stick about 1/4 of inch.  Running oil level in between the full and add marks is the best method for operation after oil change service.
Dave Atherton Retired Cat Mechanic.

[Guy Pryor]

I want to thank everyone for all the great information this will be a great help for me to do the research to find a new service center to have my Beaver serviced at
Thanks again