Stuttgart’s recent Engine Expo saw the launch of a sensor that brings us one step closer to the possibility of a sealed-for-life car engine.
Delphi claims that its Intellek Oil Condition Sensor will extend oil useful life up to 30,000 Km, and could, by the middle of the next decade, be at the heart of a lubrication system that will not require a complete oil change for the normal life of the engine.
While existing techniques estimate when oil change is required by predicting oil condition from factors like the vehicle drive cycle, oil temperatures, number of cold starts and, in some systems, a measurement of the oil dielectric, Delphi’s sensor is said to be the first that measures oil properties directly.
Having studied different aspects of oil degradation, Delphi concluded that acidity, oxidation, viscosity and contamination are the key variables. These factors determine the conductivity of the oil, a trace of which shows excellent correlation against oil condition as measured using industry-standard techniques.
The sensor is comprised of three concentric stainless steel tubes and a temperature probe. The conductivity of the oil is established by applying a low-frequency alternating potential and the oil level is calculated through an impedance measurement.
Calculations are performed by a built-in microprocessor that allows the unit to deliver processed information rather than raw data. It also gives a near ‘plug-and-play’ capability, requiring only a link to the vehicle’s powertrain databus and integration with the driver information system.
The sensor is configured to measure oil temperature, saving the cost of an additional sensor. This is expected to be increasingly useful due to the affect of this parameter on hydraulically controlled systems such as cam phasing and cylinder deactivation. The ability to measure oil level also allows elimination of the dipstick.
Delphi says that the gasoline version of the Sensor could be in volume production for the 2004-5 model year. Further developments are already under way to increase the range of parameters measured.