Even though automakers are extending the recommended oil change intervals, it is still important to check the engine oil levels between oil changes. Motors whose owners neglect to check the engine lubrication systems usually become clogged with sludge and varnish because of unapproved oil use. On rare occasions, the engine fails due to low oil level and lack of lubrication.

Oil Level Sensors

The oil level sensor obviously warns the driver when the engine oil level is critically low, but sometimes, the sensor is broken, or the vehicle isn’t equipped with one. For that reason, it is important to check the oil level whenever the vehicle is being serviced. If the level is dirty or the interval has nearly expired, recommend an oil change and other routine maintenance. If the oil appears clean but the level is low, it’s important to know the vehicle owner’s brand preference for engine oil before adding oil. Most won’t know or care, but some owners might prefer using a specific brand of oil. In any case, if the engine oil level is low, always inspect the engine and oil filter for leakage or other signs of oil consumption and make the appropriate service recommendations.

Oil Life Monitor

Modern oil life monitors use information from the Powertrain Control Module (PCM) to measure oil life, and can extend the oil change intervals 10,000 miles or more. It is important to meet manufacturer specifications when dealing with oil life monitors because the oil may not last as long as the monitor calculates it will. In some cases, sludge/varnish buildup can indicate a malfunctioning monitor. When this happens, a shorter oil change interval is recommended.

Oil Deposit Control

Modern gasoline and engine oil is formulated to prevent carbon from forming in the combustion chamber, piston rings from sticking and oil additives from contaminating the catalytic converter. Modern engines use low tension piston rings to reduce wear on the cylinders. Unfortunately, low tension rings tend to stick when the wrong type of oil is used.

Anti Scuffing Additives

Oil suppliers have removed zinc and phosphorous based additives from their oils, while this improves catalytic converter efficiency, on some vehicles, this can damage the camshafts. For those vehicles, very high quality oil is used to prevent scuffing. Older vehicles without catalytic converters use specially branded oils with additives to prevent scuffing.

Oil Life Issues

Neglected oil change intervals can ruin any engine oil. As oil accumulates miles, it becomes contaminated and forms sludge. Cold engine operation accelerates the formation of sludge. At high speeds, sludge often clogs the oil filter and oil galleries.

Engine Lubrication Problems

Heavily sludged oil will clog many more parts of the oil system and can lead to oil starvation in the motor. Oil starvation can cause many parts of the engine to take severe damage. Detergents in fresh oil often speed up clogging by loosening accumulated sludge. Your best bet when dealing with a heavily sludged engine it to replace or rebuild it. VVT engines are especially susceptible to lubrication problems due to the variable timing.

With oil prices climbing, many people take the cheap way out when choosing motor oil. But in the long run, using the right oil will always cost less than having to replace or rebuild your engine after sludge buildup.