LO 10-9 Identify potential causes of high oil consumption, the purpose and function of oil level sensors, and maintenance procedures to correct oil consumption

1.1. Oil Level Sensors

Oil Level Sensors

Oil level sensors are used to alert the operator to low oil levels. One sensor type can use ultrasonic sound waves to monitor the oil level in the oil pan during the brief initial key on, engine off (KOEO) period. The sensor monitors the correct engine oil level to avoid an overfill or a low oil level while driving or at KOEO. Typically, the sensor is mounted on the bottom of the oil pan and has a piezoelectric transducer that sends ultrasonic sound pulses into the oil. Wave reflection at the oil surface and then back to the sensor measures the time the echo is received from the oil level surface to calculate the distance and hence the oil level (Figure 64 and Figure 65) .

FIGURE 10-64: An oil level sensor uses ultrasonic sound waves that reflect back from the surface of the oil level in the oil pan.

FIGURE 10-65: Location of an oil level sensor and connector on a 6.6 L Duramax oil pan.

Locating an Oil Leak

Quickly and accurately pinpointing oil leaks is an important skill a technician needs to develop. Engine oil leaks are an offense under environmental and Federal Motor Carrier Safety Administration (FMCSA) legislation. An oil leak qualifies as an out-of-service criterion and is strictly enforced in many jurisdictions. Leaks can often be identified by the color of the leaking fluid. Diesel lubricating oil is black while transmission fluid, antifreeze, power steering fluid, and washer fluid can be red, green, gold, orange, brown, or blue. Once a leaking fluid is determined to be engine oil, it can be difficult to identify where it is leaking from because of gravity, air blown across the engine, and the creeping of oil along an edge of a component. The best method to use to identify the location of an oil leak is tracing dye, which is easily detected with a UV light. To locate an oil leak, follow the steps in Skill Drill 10-2.