OperationCAUTIONTopreventpropertydamage, ifthecoolantshouldget extremely low and the engine very hot, let theengine cool for approximately 15 minutes beforeadding coolant. Then, add coolant slowly withthe engine running. Adding cold coolant to a hotengine may crack the cylinder head or crankcase.Never use water alone.For vehicles with MaxxForce® 11, 13, 15 or Navistar ® N13engines, the cooling system is filled at the factory with Nitrite-freeShell Rotella® Ultra ELC.For vehicles with Cummins® ISX15 engine, the cooling systemis filled at the factory with Shell Rotella® ELC (Red) coolant.Navistar, Inc. recommends using only the approved coolant withthe 2010 cooling packages, and will not warrant these coolingsystems that have not utilized the recommended coolant.The label on the deaeration tank provides additional coolant/ antifreeze information. Consult the Engine Operation andMaintenance Manual for coolant service life details.Engine OilKeep oil level between the ADD and FULL marks. Never operatean engine with oil level below the ADD mark.To obtain an accurate engine oil level reading the vehicle mustbe parked on a level surface with the engine off for at least 15minutes before checking the oil level. This will ensure the oilis level in the oil pan and the circulated oil has had a chance toreturn to the pan. It is not necessary for the oil to be hot to obtainan accurate reading.When checking the oil level, the dipstick must be withdrawn andwiped clean, then inserted all the way and again withdrawn fora true check.Use only recommended viscosity engine oil. Refer to the EngineOperation and Maintenance Manual for engine oil specificationsand proper oil choice.The lubricating oil in a diesel engine becomes dark in colorafter short periods of engine operation. This discoloration is notharmful to engine parts as long as the oil and oil filter elementchanges are performed at recommended intervals.Engine Performance Problems• Low engine power can be the result of a plugged fuel filter.Fuel filters can plug prematurely due to the use of fuel thatiscontaminatedwithahighamountofsediment, microbialgrowth, or water. Fuel that has been stored for longerperiods of time may also reduce engine performance.• Failure to maintain the vehicle as required in theMaintenance Instructions and Maintenance Intervals andSpecifications sections of this manual, as well as anyseparately available Engine Operation and MaintenanceManual, can cause engine performance problems.Too low of a cetane number could cause hard starting andslower warm-up and could increase engine noise and exhaustemissions.155
