Electronic Oil Level Meter (dipstick)

Hi All, I want to make an electronic dipstick which will show low or high oil level, does anyone now of or possess a circuit diagram for this project.

Do you plan on retrofitting this project onto an existing vehicle?

That's more of a mechanical problem. How do you intend to detect the level of the oil at the end of a dipstick with electronics? Are you going to put a small float there and measure its displacement? Perhaps a capcitive scheme? Something else? Each will require different circuitry.

Also keep in mind that electronics generally won't like hot engine temperatures.

Hi Thanks for the replies here is abit more info. The dipstick will not be fitted to an engine in a car. The engines will sometimes be hot or cold after a hot bench test. I need to know if the oil fill is low or high. It needs to be done with no moving parts. Indication will be by Green & Red led`s. It needs to fit in approx 6mm hole. Hope this is of use. Thanks again for replies recieved so far.

Several ideas come to mind but they would all have to be researched to see if they would work in the environment you have and to what accuracy and repeatability. Temperature, light dispersion, TDT timing, capacitance, maybe conductivity.

The environment of a 'passive' dipstick gurantees it will get covered in oil during operation. The viscosity of the oil and how long it takes to drain from the non-wetted portion of the dipstick will determine how soon you can get a reliable reading after the engine stops. There is a reason mechanical dipsticks must be taken out, wiped, inserted, removed, and inspected to get a valid reading. You could certainly add mechanical motion to deal with those issues, depends on how fancy you want to get.

Is this for commercial, scholastic, or personal use?

How about a pressure sensor in the oil pan plug instead of trying to work with the dipstick? After the engine stops, the pressure at the bottom of the oil pan will tell you the height of the oil.

It may be easier to tap your own hole in the bottom of the oil pan than to try to find something that threads into the oil plug hole.