"Change oil" 1k before due. [Archive] - GrandAmGT.com Forum


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05-22-2005, 07:29 PM
My change oil light came on about 100 mile's ago, i was like wtf, I looked up and it wasnt due for another 1k, I dont know if they just forgot to reset it or what. Nothing has changed on the car, I had a TPS enhancer in there for about 2 weeks. But i dont think that would do it. I get my oil changed every 3k or 3 months like ur suppose to, so i dont know why im getting this light.

05-22-2005, 07:34 PM
i would say they forgot to reset the light, i could be wrong but ive heard the change oil light is inaccurate

05-22-2005, 07:35 PM
it's based on driving conditions, avg rpm's and alot of other things, not just mileage. could be it wasnt reset also. no way to tell lol

05-22-2005, 07:44 PM
IC, should i just re-set it and go off, my mileage that i know or just leave it on untill i get it changed. It is rather annoying.

05-22-2005, 07:47 PM
i cant remember what new car it is..but now thats recorded by actual RPM's which is nuts...

Mike Jung
05-22-2005, 08:49 PM
i cant remember what new car it is..but now thats recorded by actual RPM's which is nuts...
Like maybe the GA that you are driving :rolleyes:

Along with other variables, like: engine temp, cold starts, etc...

The GM OLM system is better than the BMW system, that just measures how much gasoline is used.

05-22-2005, 08:51 PM
Well Engine temp is usually between 196-200 and No cold starts, i have a auto starter that i always use. We shale see

Mike Jung
05-22-2005, 09:05 PM
Was posted in another forum:

Oil Life Monitor Stripped Bare
(reprinted from General Motors)
The patented engine oil change technology involves computerized monitoring of engine revolutions, operating temperature, and other factors to optimize the change interval selection. The typical recommended interval for gasoline-fueled passenger cars and light-duty trucks is 3,000 miles (4,800 km) or three months, whichever first occurs, when outside temperatures are below freezing and trips are short. These conditions are considered severe duty. For ideal driving conditions, relating to long trips with mild outside temperatures, the interval can be expanded to 7,500 miles (12,000 km). Starting with the 2000 model year on certain vehicles, GM will raise the maximum mileage allowed for Oil-Life System-equipped vehicles to between 10,000 and 15,000 miles (16,000 and 25,000 km), depending on vehicle brand and engine*.

The development of the Oil-Life System began over a decade ago by researchers Shirley Schwartz and Donald Smolenski, both of the GM Research Laboratories. They discovered, through various investigations, that oil degradation, in general, followed pathways influenced by service and environmental conditions. The extremes of these conditions, as shown in Figure 1, are high-temperature, high-load on one end and low-temperature, low-load on the other. In between is the large operating domain representing the majority of driving conditions. The basic design of the Oil-Life System was intended to characterize extreme operating conditions and most points in between. While the Oil-Life System does not actually monitor any single quality or physical property of the oil, it does incorporate the use of a highly sophisticated mathematical model. This model applies the known influence of oil service temperature and revolutions to characterize the remaining life. The influence of temperature, in particular, has a marked impact on oil life. The almost parabolic nature of the aging rate with temperature emphasizes the importance of this as dependent variable. On the other hand, time or running time (in the absence of mileage or engine revolution data) was not found to be a particularly good indicator of oil life, since it did not adequately distinguish between periods of extended idle and periods when engine speed was high.

The onboard calculation of oil age was simplified by using penalty factors (as opposed to equations). A penalty factor is an indication of the rate of oil aging at a given operating temperature. For any given oil, higher penalty factors are associated with faster oil-aging rates. The model uses engine revolutions as a basis for measuring duration of service. Gathering the data to show correlation of on-board measurements of oil-change intervals to laboratory oil analysis is a slow process, requiring months or years. For example, a typical short-trip service test can last two years. During the original research program approximately 130,000 kilometers were accumulated in determining the constants for the mathematical model and another 160,000 kilometers were logged in testing vehicles equipped with the Oil-Life System. The four oil analysis tests are:

1. Total Acid Number (TAN)-Concentration of acid constituents in the oil from oil oxidation and combustion products.
2. Total Base Number (TBN)-Depletion of overbase detergent additive.
3. Differential Scanning Calorimetry (DSC)-Approximates the remaining life of the antioxidant (residual oxidation induction time).
4. Pentane Insolubles (PIN)-Concentration of carbon soot and sludge.

The point at which the oil-change indicator signaled an oil change is then shown. All oil analyses results are plotted, including those data points regarded as "outliers", that is, points with values differing by more than approximately 20 percent from the trend lines from all data. It is interesting that DSC data followed a rapid decay curve from the outset. Also interesting is that both TAN rises and TBN falls at an apparent increased rate near the point where PIN rises (about 16,000 km). Even though not all of these changes occurred with each vehicle and there was usually some oscillation in the data, it was still possible to use these generalizations as guidelines to characterize the oil aging process.

From these studies and other subsequent investigations it is clear that there are distinct benefits to drivers of vehicles equipped with the oil-life monitoring systems. For those who neglect to change their oil on a regular basis, the system provides reminders that a change is due. If they need the reminder and follow through with an oil change, they'll protect their engine from premature wear. And, drivers who thought they needed to get their oil changed every 3,000 miles (5,000 km) or so, might be able to go longer between changes. This will save them money, time, and perhaps more importantly, precious natural resources.

Ref: Schwartz, S. E. and D. J. Smolenski, "Development of an Automatic Engine Oil-Change Indicator System," SAE Paper 870403.
* General Motors has set the maximum distance for normal driving on the Chevrolet Avalanche equipped with the 5.3 liter and 8.1 liter V-8 gasoline powered engines at 10,000 miles.

Author Credit: General Motors Corporation


05-22-2005, 09:07 PM
interesting. Not to sure any car should go 10k with out a oil change.

Mike Jung
05-22-2005, 09:21 PM

What type of oil are you using in your GA ?

Any long time idling ?

Any 'hard' driving ?

Chances are that at the last oil change the OLM system was forgotten & not reseted.

I myself am using a 6-months oil change interval schedule.
Using German Castrol Syntec 0W30 sythetic motor oil with an over-sized NAPA Gold oil filter.
I haven't ever seen my change oil light come on; but I don't do that many miles on it.

05-22-2005, 09:24 PM
Im useing pennzoil (sorry cant spell) No hard driving just ur basic highway/city driving. it does idle longer then most,because of the auto start. it usually runs for 5 min's before drive time.

Mike Jung
05-22-2005, 09:33 PM
I would recommend to just do a oil change & make sure the OLM system is reseted.

Since a 'dino' oil change is relatively cheap & for peace of mind.

Pennzoil dino oil is a good choice.
(I was asking because I didn't want to recommend an oil change, if you use like Mobil 1. Which would easy handle your short oil change intervals. No use wasting semi-expensive synthetic motor oil.)

& you really don't need to idle your car for 5-minutes, now that summer is coming.

05-22-2005, 09:47 PM
Or just check the dipstick....you should be able to tell if it's time for a change.

Mike Jung
05-22-2005, 09:52 PM
Determining Proper Oil and Filter Change Intervals: Can Onboard Automotive Sensors Help? (http://www.practicingoilanalysis.com/article_detail.asp?articleid=562&relatedbookgroup=OilAnalysis)

Sabrin Khaled Gebarin and Jim Fitch, Noria Corporation

In recent years, the cost of inappropriate drain intervals to the economy, to the environment and to car owners has received closer inspection. In the United States, the average car owner changes his/her oil at just less than 5,000 miles. Conversely, in Europe the average oil change interval is more than 10,000 miles. Assuming 10,000 miles is a more optimum interval, approximately 300 million to 400 million gallons of engine oil (worth about $1.5 billion, not including labor) in the United States are consumed unnecessarily. With increasing environmental and economic pressures, the potential waste can no longer be easily glossed over.

There are, however, negative consequences to overextended oil drains. In diesel engines for instance, overextended oil drain intervals have been shown to increase engine wear by more than 20 percent with a corresponding reduction in horsepower and fuel consumption. One could safely project that overextended drains in passenger car applications would have a similar negative outcome. This of course presents a real dilemma to the car owner. What exactly is the correct interval? In the quest for optimum lubrication, car owners often receive conflicting advice from vehicle owner’s manuals, mechanics, quick-lube operators and auto parts merchants. Some of this advice is peppered with strong admonishments for bucking conventional wisdom.

As a practical matter, we must consider a range for an oil change from around 2,000 miles to well over 15,000 miles. Most car makers generally recommend changing the oil for automobiles and light trucks burning gasoline once a year or every 7,500 miles, whichever occurs first. For diesel engines and turbocharged gasoline engines, the recommendation is typically a more accelerated 3,000 miles or six months.

Diesels tend to generate much more soot and acidic combustion blow-by in the crankcase. Turbochargers subject motor oils to high temperatures and are more prone to form engine deposits. A turbo can spin at speeds exceeding 100,000 rpm (about the same speed as a dentist’s drill). When an engine is shut off, the heat inside the turbo bearing housing builds from the high frictional heat and hot exhaust gases. The oil in contact with these hot bearing surfaces can crack, forming coke (hard carbon deposits) and hydrogen. This can lead to bearing damage.

If you read the fine print in your car owner’s manual, you will see that the 7,500-mile change interval is for vehicles driven under normal or ideal conditions. This is where the problem lies. What exactly are these ideal conditions and what are the consequences of not ideal with respect to motor oil condition and engine wear? What many perceive to be “normal” driving is actually “severe service” driving from the standpoint of the oil. For instance, the following are examples of severe service driving: frequent short trips (especially during cold weather), stop-and-go driving, driving in dusty conditions (gravel roads, etc.), and high-temperature conditions. Under such conditions, the general recommendation found in owner’s manuals is to change the oil every 3,000 miles or six months.

The real problem rests in the attempt to generalize. In reality, there are many unique conditions and factors that influence the decision. For illustration purposes, these conditions and influencing facts can be categorized in two ways as shown in the lists below:

1. Factors and Conditions That “Shorten” the Oil Change Interval:

Short-trip Driving - The problem is most pronounced for frequent trips under five miles in cold wintertime conditions. Water and fuel have a tendency to accumulate in the crankcase when the oil temperature doesn’t reach the thermostat setting.
Road Dust - Driving in dusty conditions (dirt/gravel roads) with an economy-grade oil filter can turn your motor oil into more of a honing compound than a lubricating medium. The dirty oil generates more wear metals which increase the risk of sludge formation and corrosion from acids.
High-Mileage Engine - Engines with more than 75,000 miles generate more blow-by gases, unburnt fuel and corrosive agents that enter the crankcase oil.
Diesel Engines - Diesels produce more soot and acidic blow-by products.
Flex Fuels - Alcohol-gasoline blends are prone to accumulate water in the crankcase.
Turbo-charged Engines - High temperatures distress the base oil and additives.
High Oil Consumption - While on one hand high oil consumption replenishes additives, on the other hand the affliction is also associated with high blow-by of combustion gases into the crankcase.
Hot Running Conditions - Hot running conditions, including desert terrain, in general can lead to premature oil oxidation, volatility problems and rapid additive depletion.
Desire for Long Engine Life - Shorter drain intervals increases the safety margin in the event of premature oil failure.
Towing/Heavy Loads - Generally relates to hot running conditions, thin oil films, higher shearing of viscosity index improvers and more wear metals in the oil. Wear metals catalytically shorten oil life, causing premature oxidation, sludge, acids and deposits.
2. Factors and Conditions That “Lengthen” the Oil Drain Interval:

Synthetic Lubricants - Premium synthetic lubricants have excellent oxidation stability, thermal stability and shear stability.
High-Capture Efficiency Oil Filter - Controls catalytic wear metal production.
Highway Miles (predominate) - Lower average engine revolutions and fewer operating hours per distance traveled (miles) compared to slow-speed urban driving.
New Engines - Low levels of engine blow-by after the first 500 to 5,000 miles and less than 50,000 miles (unless oil consumption is high).
Frequent Oil Inspections - Simple and frequent oil inspections can be effective at identifying various motor oil problems. Refer to the article titled “Dipstick Oil Analysis” in the November-December 2003 issue of Practicing Oil Analysis magazine.
Environmental Concerns (waste oil) - Emphasis on reducing waste oil generation.
Low-value Vehicle - Many owners of automobiles with low resale value prefer extended drains to keep their costs low. Others use frequent oil changes as a strategy to limp along a car in its twilight years.
For most of us, distilling all this down to an optimum oil change interval is like trying to nail Jell-O to the wall - too many variables and too much guesswork. There has long been a need for a practical and effective workaround. Rather than attempting to quantify the collective impact of these many conditions and factors, the best approach might simply be for the oil to tell us when it needs to be changed. Oil analysis - now there’s a fresh idea!

More and more oil analysis laboratories are targeting passenger car owners to grow their market. However, as a practical matter, laboratory oil analysis is out of reach for nearly all except for hardcore car enthusiasts. This has led to a flurry of new onboard sensors and related technology being advanced by companies with sizeable research budgets, eyeing the huge transportation industry. The following is a review of these many new and evolving innovations.

Current and Pending Technologies
General Motors Corporation GM Oil-Life™ System
The General Motors (GM) Oil-Life System, first introduced commercially in the 1998 Oldsmobiles, determines when to change the oil and filter based on several operating conditions. The technology does not actually monitor any single quality or physical property of the oil. Instead, the Oil-Life System monitors engine revolutions, operating temperature, and other factors that affect the length of oil change intervals.

The sensor is based on GM’s determination that nearly all driving conditions can be grouped into one of four categories: easy freeway driving; high-temperature, high-load service; city driving; or extreme short-term, cold-start driving. GM discovered that oil degradation in the first three categories was largely a function of the oil temperature. During extreme short-trip driving (the fourth category), the principle cause of oil degradation is water condensation and contaminants in the oil - the lower the oil temperature, the greater the contamination.

The software automatically adjusts the oil change interval based on engine characteristics, driving habits and climate. When the system notifies the owner that it is time for an oil change, the owner can go to the nearest GM dealer and a technician will change the oil and filter, properly recycle the oil, then reset the vehicle’s oil life system. ...

... If the owner prefers to change his/her oil, the GM owner’s manual provides instructions on resetting the timer. Because the Oil-Life System does not actually sense oil condition, it is important for the engine computer to know when an oil change takes place. Therefore, the Oil Life System must be reset each time to ensure accurate and proper performance.

It is now available on all light-duty North American GM cars except for some models of Buick Park Avenue and Le Sabre, Pontiac Bonneville and Sunfire/Sunbird, Chevrolet Tracker, Cavalier and Malibu, S10/Sonoma trucks, Astro/Safari Vans, and the Pontiac Vibe.

Mike Jung
05-22-2005, 09:53 PM
DaimlerChrysler Corporation Flexible Service System
DaimlerChrysler’s version of the oil monitor is called ASSYST in Europe and the Flexible Service System (FSS) in the United States. Like GM’s sensor, the FFS uses a computerized system to track multiple engine operating conditions. From research on oil quality through the span of an engine’s life, Daimler discovered that the breakdown in oil is determined by such factors as driving habits (frequent short trips vs. long trips), driving speed and failure to replenish low oil levels. Therefore, the FSS monitors time between oil changes, vehicle speed, coolant temperature, load signal, engine rpm, engine oil temperature and engine oil level. It uses this information to determine the remaining time and mileage before the next oil change and it displays the information in the vehicle’s instrument cluster.

In addition, Daimler discovered that oil degradation is correlated directly with its ability to conduct electric current. Therefore, Daimler has fitted V-6 and V-8 engines with a digital oil quality dielectric sensor, that is mounted above the oil pan along with an analog oil level sensor. This sensor measures changes in capacitance, which effectively is a proxy for the amount and type of contaminants and oil degradation products present in the oil. An increase in dielectric constant (less resistance to electrical flow) indicates oil contamination and degradation.

Daimler-Benz (Mercedes-Benz) has been incorporating the sensor into its vehicles since 1998.

Delphi Corporation INTELLEK® Oil Condition Sensor
The INTELLEK Oil Condition Sensor uses both a computer algorithm as well as a sensing element that directly measures various oil properties. The algorithm takes into account important factors affecting the rate of oil deterioration like temperature, driving severity, oil level and oil type. It measures the temperature every 10 seconds to verify whether it reaches a specific normal operating temperature before the engine shuts off. It also records the number of times the engine turns on and off.

A proprietary capacitive sensing element is the core technology. It tracks the oil’s conductivity, detects water and glycol contamination, oil temperature, and determines the oil level. According to Delphi, the oil’s conductivity is important because it characterizes additive depletion and changes in viscosity and acid number.

The INTELLEK Oil Condition Sensor tracks the many different parameters using onboard software to indicate when the oil is nearing the end of its service life. It attaches to the oil pan or wherever there is a continuous flow of oil.

Continental Temic Microelectronic GmbH QLT Oil Condition Sensor
The QLT sensor was launched in 1996 to monitor engine oil quality, level and temperature. Two sensors simultaneously and continuously monitor diesel engine oils containing soot. The instrument also monitors nitric oxide and oxidation products in spark-ignited engines, as well as water and fuel contamination. Because these factors influence the oil’s electrical properties and permittivity (ability of a material to resist the formation of an electric field within it), an effective oil condition sensor is achieved, according to the manufacturer.

The QLT also has an integrated precision probe that allows it to measure critical temperatures and exact oil levels. It can track temperatures ranging from -40°C to 160°C. The oil level, up to 100 milliliters, is calculated by a second capacitor.

Voelker Sensors Inc. Oil Insyte
The Oil Insyte sensor uses a patented technology based on the electrical properties of an oil-insoluble polymeric bead matrix (see Automotive Sensor Technologies Explained below for more details). The Oil Insyte employs an in-line method for continuous oil condition monitoring with an LCD readout providing detailed information about oxidation, additive depletion, soot contamination and oil temperature. The technology does not require external calibration standards and reports oil condition independent of viscosity.

Voelker Sensors Inc. - Oil Insyte

According to the manufacturer, the sensor measures key indicators of oil degradation and allows the conventional analyses approach of oil monitoring (sampling and analysis) to be combined into a single more efficient analysis. No assumptions are required as to the condition of the engine or the initial baseline quality of the oil.

The Oil Insyte technology measures oxidation and additive depletion, and has the ability to examine the interdependence between the two. They claim difficulties encountered with sensors that measure only the electrical properties of oil (conductive additives masking the true condition of the oil) are overcome by using a differential technique where the conductivity of the bead matrix is measured relative to the conductivity of the oil. The true polar condition of the oil can then be determined.

The soot detection feature of the sensor determines the amount of undispersed agglomerated soot (vs. dispersed finely divided soot) present in the oil. Depending on the oil’s additive package, the same amount of undispersed soot can be present at 1 percent to 2 percent (for the base oil without dispersants) as a fully formulated motor oil with more than 7 percent soot.

Lubrigard Ltd. Lubrigard Oil Condition Monitoring Sensor

Lubrigard Ltd. - Lubrigard Oil Condition Monitoring Sensor
The Lubrigard sensor unit is designed to be fitted by the original equipment manufacturers (OEMs) to new cars and trucks to warn the operator of abnormal lubricant conditions. According to the manufacturer, it indicates when an oil or filter change is necessary or when the oil should be inspected or tested.

The sensor was designed to optimize oil drain intervals and to detect problems like coolant leaks, metallic wear debris and oil degradation by direct measurement. It is particularly useful for measuring high concentrations of soot in diesel engines’ crankcase oils.

The sensor’s technology is based on the dielectric loss factor, also known as Tan Delta. According to Lubrigard, this method is more sensitive to changes in contamination than other dielectric measurements. At the same time, it is tolerant of normal differences in operating temperatures and lubricant formulations. To compensate temperature variations, a temperature sensor communicates with the unit’s microcontroller. The technology monitors soot, water, coolant, oxidation and/or wear particles.

The sensor is designed so that it can be connected to the car’s onboard computer. Outputs and alarms are displayed in accordance with the auto maker’s preference. For example, a dashboard display could show a thermometer-type scale growing in size and changing color from green through amber to red as the oil degrades.

The Lubrigard sensor is readily mountable on any engine, gearbox or hydraulic system, and it will work in both gasoline and diesel engine oils.

Symyx Technologies Inc. Solid-State Oil Condition Sensor
Symyx Technologies developed a sensor that uses a solid-state micromechanical resonator and a special signal-processing algorithm to measure important physical properties of lubricants. This sensor can measure three independent physical properties: viscosity, density and dielectric constant. This is significant technology because the direct measurement of a lubricant’s physical properties can provide important information about changing lubricant and engine health.

The miniature sensor allows for innovative packaging and strategic placement of the sensor in an engine to provide in-situ oil analysis without negatively affecting the design parameters of an overall system. The extremely fast response time and signal processing of the sensor allows for real-time measurement of lubricant properties.

According to Symyx, its solid-state resonator technology will operate in various types of fluid environments that experience a broad range of temperature, pressure, shock, vibration and fluid flow.

Symyx is actively pursuing companies interested in using or licensing this technology to measure and monitor the quality and condition of lubricants and other fluids. Already, several Symyx licensees of the sensor are commercializing the technology for use in the industrial and consumer markets. It is also currently being used in Symyx’ laboratories to measure the physical properties of gases and liquids.

Mike Jung
05-22-2005, 09:54 PM
Bosch GmbH Multifunction Oil Condition Sensor
Bosch is developing a multifunctional oil sensor that will determine oil level and oil condition. The oil level information will allow the oil dipstick to be omitted from the automobile.

Monitoring the engine oil condition is primarily intended to optimize oil drain intervals. However, it also provides increased insight into the actual state of the engine, which enables the possible detection of approaching engine failures or change in lubricant quality. The oil condition sensor will constantly measure the oil’s viscosity, permittivity, conductivity and temperature. The measured viscosity and permittivity (or dielectric constant) are the primary values supporting the oil condition evaluation. Commonly, chemical oil deterioration is associated with an increase in viscosity, whereas mechanical wear (shear) and fuel dilution lead to a decrease in viscosity.

A novel microacoustic device determines the viscosity. This device utilizes the piezoelectric effect to electrically excite high-frequency mechanic (or acoustic) vibrations at a sensitive surface. When this sensitive surface comes into contact with the oil, the electrical device parameters, such as oscillation frequency and damping, are changed according to the oil’s mechanical properties, especially viscosity. Thus, the viscosity can be electrically detected by measuring these parameters. In contrast to conventional viscometers, which are commonly used in laboratory applications, the microacoustic sensor does not contain any moving parts. Furthermore, due to its small size, it can be easily incorporated into the multifunctional oil-level and condition sensor.

Bosch’s multifunctional oil sensor is suitable for spark-ignition and diesel engines.

Eaton Corporation Fluid Condition Monitor
Eaton has developed a unique fluid condition monitor (FCM) technology that can monitor multiple fluid properties. The Eaton FCM is an in-situ real-time sensor based on impedance spectroscopy - a technology that measures multiple electrical properties of a fluid. It uses very small alternating current (AC) signals, which do not permanently disturb the fluid or the electrodes used in the measurement. Eaton’s FCM technology is differentiated by two critical attributes: it measures surface properties of the fluid in addition to bulk properties, and it has more degrees of freedom to enable the independent tracking of multiple lubricant parameters.

Measuring bulk properties reveals information about the conductivity (concentration and charge of ions) and dielectric constant (size, shape, and polarizability of the base fluid and its additives). Measuring the surface properties provides a quantitative measure of the physical and chemical properties of a fluid at the fluid-to-metal interface. This is a powerful technique when it is correlated to the real and measured physiochemical property changes occurring in aging or stressed motor oils.

The current prototype sensors are oil pan-mounted and include temperature-sensing capability. A small electronic module is used for signal conditioning, data capture and analysis.

Automotive oil condition monitoring is far from a mature technology. As this technology progresses and becomes more popular in the automotive industry, there will be many generations of sensors developed to improve accuracy and range of capability. While some vehicles come standard with oil change technologies today, the majority do not. The companies developing these sensor technologies must be able to convince the automotive industry and the public of their general reliability and value. If this is successful, we may see condition-based oil changes become the latest trend in vehicle technology over the next few years.

Special thanks to Joe Hedges with Voelker Sensors Inc; Ronald Johnson with Eaton Corp.; and Jeryl Hilleman and Mark Ulrich with Symyx Technologies.


Capacitive Measuring Principle to Control the Oil Condition. (2003, May 12). Retrieved September 25th, 2003 from Continental Temic.
Fitch, James C. (2003). How to Select a Motor Oil or Filter for Your Car or Truck. Tulsa, Okla.: Noria Corporation.
How does FSS, the Mercedes-Benz M-Class Flexible Service System, Work? (n.d.). Retrieved September 25, 2003 from http://www.4x4abc.com/ML320/ML_FSS.html
Intellek Oil Condition Sensor. (n.d.). Retrieved September 25, 2003 from Delphi Corporation Web site: http://www.delphi.com/pdf/e/int_oil_cond.pdf
Oil Level Sensor and Oil State Sensor. (n.d.). Retrieved October 3, 2003 from Bosch Web site: http://www.kraftfahrzeugtechnik-heute.de/k/en/start/product.jsp?mfacKey=ae_17_oels
Pecuniary Inc. Engine Oil Sensors and Extended Drains. (n.d.) Retrieved September 25, 2003 from http:www.pecuniary.com/newsletters/oil-sensor.html
Schwartz, S. E. and Smolenski, D. J. Development of an Automatic Engine Oil-Change Indicator System. SAE Paper 870403.
Automotive Sensor Technologies Explained

Capacitance Method
A capacitor consists of two conducting plates separated by an insulating material called a dielectric. In the case of oil condition sensors, the oil is the insulating fluid. Capacitance is dependent on the surface area of the plates, the gap between the two plates and the insulating material. As the oil degrades, the capacitance measures this change. Capacitors store charge over time. Similar to filling a bucket with a hole at the bottom, it provides pressure on the hole when it is full. A capacitor takes time to fully charge and it also takes time for it to discharge. When it is fully charged, voltage is provided across the capacitor.

Dielectric Constant
A dielectric is an insulator. Dielectric constant is the rate of electric flux density produced in a material to the value in free space provided by the same electric field. This technique is able to detect when a change has occurred in the oil that alters the oil’s dielectric properties. These include oxidation, water, acids, mixed fluids and wear debris. There are only subtle differences between the capacitance and dielectrict constant methods.

Electrochemical Bead Matrix Method
This is a proprietary technique that employs a polymeric bead matrix (held between two conducting permeable surfaces) containing charged groups that serve as a conductive medium for measuring the solvent properties of oil. This method also works similar to the way a battery works. Milligram-sized charged resin beads are contained between two conducting surfaces separated by a nonconductive medium. The charged groups of beads (composed of both anions and cations) adjust to form an electrochemical bridge of varying strength depending on a relative change in the polarity of the oil. Because engine oils are relatively nonpolar and the beads are ionic, the beads do not form a conductive bridge. As the oil starts to degrade or become soot contaminated, the fluid becomes more polar (conducive to ionic interactions) and a bridge begins forming. This relative change in conductivity or capacitance is then measured between the two conducting surfaces.

Algorithm Method
This method uses mathematical models based on research to determine the optimum oil change intervals. Conditions like fluid temperature, speed, time and other critical factors are monitored and incorporated into the algorithm. Because the method does not actually test the condition of the oil, it cannot test for engine damage, coolant leaks, etc.

Acoustic Waves Method
See description of Bosch’s Microacoustic Sensor above.

Dielectric Loss Factor
See description of Lubrigard’s Oil Condition Sensor above.

Please reference this article as:
Sabrin Khaled Gebarin and Jim Fitch, Noria Corporation, "Determining Proper Oil and Filter Change Intervals: Can Onboard Automotive Sensors Help?". Practicing Oil Analysis Magazine. January 2004

05-23-2005, 07:30 AM
I would recommend to just do a oil change & make sure the OLM system is reseted.

Since a 'dino' oil change is relatively cheap & for peace of mind.

Pennzoil dino oil is a good choice.
(I was asking because I didn't want to recommend an oil change, if you use like Mobil 1. Which would easy handle your short oil change intervals. No use wasting semi-expensive synthetic motor oil.)

& you really don't need to idle your car for 5-minutes, now that summer is coming.

I'm getting my oil changed this weekend. Just because its getting closer now to its scheduled date. I'm also going to remind them to re-set the system.

05-23-2005, 08:53 AM
mine always comes on early, cause i am wot 3/4 of the time driving, i just change it when it pops up, 20$ isnt a lot of money to keep the car running efficiently (yes i use the normal run in the mill cheap oil... and the car runs excellent, so.. myeh) my dad on the other hand, i think it was upwards of 70$ for his last oil change...

Mike Jung
05-23-2005, 09:01 AM
...I'm also going to remind them to re-set the system.
Just reset it yourself, after getting your GA back from the oil change.
It just takes a few seconds.

That way there is no question if the OLM was reset.