Oil Usage--General Info

[buddyten]

Hey Guys and Gals:
Have an 80 Eagle with 8V71.    Had new rings, inserts, etc and injectors rebuilt approx 2 yrs ago.   It is used a a tour type bus for our gospel group.   We likely use it less than 20,000 miles per year.   We are having to use quite a bit of oil (probably a gallon every 500 miles).   Have always used Mobil Delvac 1240 40 wt.    It has plenty of power, and oil pressure maintains at around 48-52 (with 48 being in 5th gear, running about 65 mph).   It does smoke some on start up, but clears within a few minutes.    One of our members followed the bus not long ago, and he says we are getting little or no smoke except on gear changes (puffs) or under load.  Idle oil pressure is around 5-10 psi.

I read somewhere on one of the chat rooms that the slobber tubes have check valves that need to be maintained.   I notice that we are getting very little slobber after idling (maybe a couple tablespoons after a 10 minute idle).   We are getting very little on the back of the bus.   I do note that we have what appears to be an oil leak somewhere around and/or underneath the exhaust manifold on the passenger side.   

Couple questions :

1)  Will the slobber tubes check valves cause excess oil usage if they are not operating properly?
2)  Any suggestions on where to look for the oil leak or where it might be.

Incidentally, just had a new air compressor installed recently.  We questioned a mechanic and he advised that it sometimes takes 50,000 miles for a DDEC to break in and all the rings to seat, and it will use excess oil until they do.

Since we use it only on weekends, and usually less than 500 miles per weekend, for about 32-36 weekends of the year, it is doubtful we have put 50K on it since redone.

Any thoughts, suggestions, help would be appreciated.   We are not mechanics, and any help would be most appreciated from the experts.

[luvrbus]

Probably the guy broke some of the oil rings on installing or installed the oil rings up side down 1 gal in 500 miles is in excess I would check the blower also

good luck

[desi arnaz]

I have found keeping her a gallon low helps with oil consumption....I could be wrong but it works for me!

[hargreaves]

Rocker cover, and blower oil feed tube are the most common oil leaks.  I would check the commpressor gasket as well. The air box valves will not cause excess oil consumption.   Cheers,  Gerry

[Scott & Heather]

Interesting...when you guys say "blower oil" do you mean to the twin squirrel cage fans? If so, why does mine have a tube with a cap and handle on it (looks like a trans fluid fill handle or something like that).

[bevans6]

Scott, that is the fan gearbox, and it has an oil fill on it so that you can fill it with oil...   It takes engine oil, and if you clean it up you will see a level sight port on the front of it which will let you see the oil level.  The blower of which they speak is the "supercharger blower" on top of the engine.  The oil feed line and the drive tube on the back of it are notorious for leaking copious amounts of oil.  Also, if the oil seals on the rotors inside it are bad a lot of oil will get sucked inside and burned.

Brian

[luvrbus]

If I recall Buddy's guy just did a ring job no new liner kits if he tried to load the pistons from the top without removing the liner Buddy probably has problems,the piston pin seals,broken oil rings,blower seals and valve seals will cause his problem and there is no way to check the oil rings through the air box covers.

A gal in 500 miles he needs some attention to find the trouble fix the leaks and then proceed on if the dip stick is marked right no need to run 1 a gal low it just causes higher oil temps when the oil and water temps gets hot the 2 strokes will use more oil I have found out over the years  with my 92 series

DD says 20,000 + miles for seating time for the rings the beauty part about a 2 stroke was rebuild it hit the road wide open no break in periods

[buswarrior]

buddyten reported in his original post "getting very little on the back of the bus"

Whatever leaks, the coach wears on the rear, from the vortex going down the road. Highway speeds are not necessary, transit coaches show what leaks on their rears too.

If it was leaking a gallon in 500 miles, that would not have been his report.

Most of that oil is going through the engine.

happy coaching!
buswarrior