Fleetguard Oil Filters
Protecting the oil system of your Cummins engine.

This page is dedicated to protecting your oil system through the use of Fleetguard oil filters.

For a quick lesson on why oil filters need to be replaced, read on. If you are a detail person and want to know even more, jump to Types of Contamination

Nothing will damage your engine as quickly as oil that is not properly cared for. Although coolant runs a close second, without oil maintenance your engine basically shuts down.

The most drastic of failures is rod bearing or main bearing failure due to low oil pressure. These bearings (which directly contact your crankshaft) have oil "pressurized" past them. When the oil becomes too contaminated or oil pressure is too low, the bearing can "seize" to the crankshaft. When a rod bearing seizes to the crankshaft, the crankshaft is damaged. When a main bearing seizes to the crankshaft, the crankshaft is damaged and most often the engine block also. The main bearing "spins", wearing the block where the bearing rides so that the block will not hold even a new bearing.

Using a Fleeguard oil filter can reduce your risk of damage. Cummins filters are built for Cummins engines and Fleetguard oil filters are original equipment (OEM).

Your engine oil lubricates and protects internal engine components. As the oil accumulates age and use, it is altered in two ways:

1.) The oil becomes contaminated.

2.) The viscosity of the oil is decreased.

You should have your engine oil sampled and lab tested occasionally to check for contamination and viscosity, especially if you are interested in performing extended drain intervals.

Types of Contamination

Contamination normally consists of one or more of the following:

1.) Metal

2.) Fuel

3.) Soot

4.) Water & Coolant

Metal Contamination - Metal contamination is mostly from engine wear, but performing regular oil samples can sometimes tell of an upcoming failure. See the following list to link metals to engine components:

Metal Type Possible Component
Iron Cylinder liners, rings,gears, crankshaft,camshaft, valve train,oil pump gear, wristpins
Chrome Rings, liners, exhaustvalves, shaft plating,stainless steel alloy
Aluminum Pistons, thrustbearings, turbobearings (Cat)
Nickel Valve plating,steel allory fromcrankshaft, camshaft,gears from heavybunker type dieselfuels
Copper Lube coolers, mainand rod bearings,bushings, turbobearings, lubeadditive
Lead Main and rodbearings, busings,lead solder
Tin Piston flashing,bearing overlay,bronze alloy, babbitmetal along withcopper and lead
Silver Wrist pin busing(EMDs), silver solder(from lube coolers)
Titanium Gas turbine bearings/hubs/blades, paint(white lead)

Fuel Contamination - Fuel contamination is caused by unburned fuel in the oil. Common causes of this would be overfueling injectors, leaking injector o-rings or internally leaking engine mounted fuel pump. Although most oil samples will show some fuel in the oil (this is normal), a test reading of lower than 2% fuel is desired.

Soot Contamination - Soot contamination is basically carbon that is in the oil. Soot is most often due to incomplete combustions, which can be caused by worn piston rings or valve guides, poor fuel spray pattern from injectors, or plugged oil filter. Once again, an oil sample will almost always show some soot contamination, although a reading of lower than 3% is desired.

Water Contamination - is water or coolant found in the oil. Most often water is due to condensation, and the amount of water will vary with engine application. Coolant should not be found in your oil. If it is, common sources of coolant would be leaking liner seals, pitted or cracked liner, internally leaking water pump, or leaking oil cooler. It is often hard to find water or coolant in the oil. This is because the oil reaches temperatures above the the boiling temperature of water, causing most water and coolant to be evaporated out of the oil system. An oil sample test result of less than .1% is desired.


Although we are working towards our goal of allowing you to purchase Fleetguard oil filters online, we have not yet finished setup on our site. If you need a Fleetguard oil filter, it is an option to purchase through our Ebay store at Diesel Service Parts


For more information on other types of Fleetguard filters, use the following links:

Fleetguard Air Filters Fleetguard Air Filters
Fleetguard Fuel Filters Fleetguard Fuel Filters


Return from Fleetguard Oil Filters to Home Page