Understanding Oil Contaminants

Many times I hear people say I tried extending my oil drains but my oil samples always came back with issues so I had to drain my oil. When I ask what type of issues it is usually, fuel in oil, excessive soot, increased or decreased viscosity, antifreeze in oil or excessive wear metals. When queried as to what preventive maintenance they perform regularly the answer is usually very vague. Sure changing your oil is part of a preventive maintenance program but so is keeping valves properly adjusted, keeping injectors clean and functioning properly, repairing air/oil/coolant leaks, replacing air/fuel/oil filters, replacing worn belts and having properly functioning temperature and pressure gauges.

Improperly adjusted valves (overhead) can result in excessive soot or fuel dilution as valves are not properly closed resulting in lost compression/unburned fuel and fuel leakage past valve seats. A loose or open valve releases air altering the air/fuel ratio resulting in unburned fuel (soot) and lowers fuel economy. Valves that are too tight can cause cam shaft wear resulting in premature cam shaft or roller following bearing failure. A wise person schedules a periodic overhead to have the valves adjusted. If you start to see signs on your oil samples of camshaft wear metals (nickel, iron etc.) or soot / fuel issues an overhead may solve the problem.

Injectors are another item that should be checked periodically especially if a fuel dilution issue shows up on your sample. A good indicator of injector leakage is rough running when started after sitting overnight. Injector leaks excessive fuel into a cylinder and it will run rough until the fuel is blown out or converted to soot.

Air leaks cause the air compressor to run constantly creating excessive heat and overheating oil as it passes through the compressor. If you have high viscosity, oxidation, low base all indicators of overheated oil and excessive lead from bearing wear the air compressor may be the cause if no copper or aluminum wear present.

Oil leaks result in low oil levels while running. The lower volume of oil does not allow the oil to properly cool in the crankcase before re-entering engine. This overheats the oil causing high viscosity oxidation and low base issues. Running just one gallon low means 10% less oil in engine. Fix leaks promptly and check oil levels daily.

Coolant leaks are not always visible externally. If coolant levels run lower than the fill line and no visible leaks appear on ground or engine then the leak is either putting coolant in oil, exhaust or intake, none of which are a good thing. If you have a coolant leak and sample shows potassium and sodium in high levels than chances are coolant is infiltrating the oil which will eventually create excessive wear to internal parts. Don’t take coolant leaks lightly they can and will cause high dollar breakdowns.

Replacing the filters is mandatory, dirty air filters block air flow causing engine to starve for oxygen, resulting in unburned fuel (soot) as well as decreasing fuel economy. Overuse of oil filters cause filter to restrict oil flow and potentially going into bypass mode sending unfiltered contaminated oil through engine. This is a sure recipe for disaster and catastrophic engine failure. Overuse of fuel filters starve engine of proper fuel levels again adjusting fuel to air ratio creating soot and lowering of fuel economy. Watch your oil samples for signs of soot development or excessive wear metal results and take the necessary action to replace the proper filters to correct the situation.

I can’t tell you how many times I have heard someone say my belt broke or my fan stopped working but I was able to baby it in to the next truck stop. A visual inspection of a belt may have prevented the engine oil and engine from overheating. A few seconds of preventive attention will save you $$$.

Gauges are installed on the dashboard for a reason having one that is inoperable is unacceptable. If oil pressure drops without you knowing it or temperature increases and you don’t shut engine down the next sound you hear will not be a very pleasant one.

Oil drains can be extended with the proper type of bypass filter or on-board oil refining system, if engines are properly maintained. Saving $$$$ on oil drains and keeping oil clean will help you defray the costs of proper maintenance.

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