Understanding Oil Contaminants

Tom Bock
March 2019

The questions I get most often: is why does motor oil need to be changed? Why does it lose the ability to protect the engine? The simple answer is if you can keep the oil clean it does not require periodic changes.

Since the early 1900’s we have known that the base oil does not break down, it becomes contaminated with solid and liquid contaminants and the additive package loses potency to properly protect the engine. The used oil can be recycled as a base oil, by removing the contaminants and reformulating the oil with a new additive package. The additives in lube oil fail when oil is over heated, contaminated with liquids (fuel, water, antifreeze) or solid particulates (soot, wear metals) that cause the oil to lose the ability to properly protect the engine from metal on metal wear damage. Keeping oil free of these contaminants and maintaining proper oil levels will reduce the rate of deterioration of your oil and keep the engine running more efficiently.

Having a failure of a cooling system with a blown hose or defective cooling fan will cause overheating issues, as well as pulling a heavy load upgrade for an extended period of time. The number one reason for overheating occurs when the engine oil levels are not properly maintained and there is insufficient oil to properly dissipate the heat caused by combustion. A close second is the flow of oil not maintained at normal operating flow rates. This is due to oil filter or galley way blockage caused by sludge, defective oil pump, improperly maintained oil filters or oil leakage. Engines today run hotter with double turbochargers and some engines are experiencing gelling issues in filters caused by antifreeze intrusion that restricts flow and lowers oil pressure. Checking and topping off oil frequently, changing filters timely, maintaining engine to avoid leaks and paying attention to oil pressure will usually prevent overheating issues. Remember, running one gallon low reduces 10% of the engine’s oil, placing extra stress on the remaining oil to dissipate heat.

Solid contaminants, soot, dirt, and wear metals will eventually accumulate in quantities that will affect the oil’s ability to properly flow and dissipate heat. Soot, dirt, oil and water will create sludge that blocks galley ways and filter operation. Wear metals will become trapped between tolerances and cause additional wear. Using a good quality full flow filter with a secondary by pass filter will help decrease the accumulation and allow for longer useful life of the oil.

Liquid contaminants; water, diesel fuel and glycol contaminate oil causing the formation of acid, increasing oxidation, sludge and deterioration of additive chemicals. The water reacts with the sulfur and nitrogen in oil to form sulfuric and nitric acids as well as adding oxides to oil that corrode and rust engine parts. Diesel fuel will decrease the viscosity of the oil and affect the film strength of the oil to properly bond with metal parts. It is this oil film that protects engines from metal to metal wear. Once the film is compromised the wear levels increase rapidly. Glycol does not enter the oil during normal operation but by some defect in coolant system causing intrusion. Unfortunately, since the advent of EGR and Oil Coolers there is an increase in glycol intrusion in engines

Using a bypass filtration system that removes both solid and liquid contaminants will extend drain intervals and the life of your engine, reduce oil maintenance expenses and put more $$$$ to your bottom line. Stop by OPS Booth 68216 at Mid America Truck Show to learn more about systems available,

Any questions or suggestions for topics for this column please email me at: [email protected]