CONTINUOUSWAVE

Q1: on a 1992 Mercury 150-HP V6 engine with electrically-controlled fuel induction, what is the sensor that is located at the bottom base of the oil filter?

Q2: could the sensor that is located a the bottom base of the oil filter be the cause of an aural alarm?

BACKSTORY
The 1992 Mercury 150-HP engine causes a continuous aural alert beeper to sound after engine start. After engine start the exhaust smoke has a blueish tint, which I can infer to be evidence of oil mixed into the gasoline fuel. [The overboard confidence indicator is discharging] water [which I infer means the cooling system is operating] okay.

I have [possibly means that the engine has] containers [possibly means oil reservoirs] [that are] full of oil.

I changed [the] top oil tank top oil.

The engine uses electrically-controlled fuel induction (EFI).

[Moderator's note: deleted a survey question that asked readers to indicate if they did or did not possess certain knowledge. Please do put questions to readers in a the form of a survey asking the readers if they have a certain knowledge.]

Cvin wrote:Q1: on a 1992 Mercury 150-HP V6 engine what is the sensor that is located at the bottom base of the oil filter?

I do not believe that in 1992 Mercury was making any engines which would have had an oil filter.

Perhaps you are trying to refer to a large diameter canister filter that is in the fuel supply line.

If the filter you describe as an "oil" filter is actually in the fuel line, to have a sensor in the fuel filter would be unusual in my experience, particularly on a c.1992 Mercury engine.

Please give a better description of the filter.

Regarding the onset of an aural alert sound after engine start: typically on most outboard engines in c.1992 an aural alert beeper was used to signal to the operator the existence of some abnormal condition, and the sounder was connected to several different sensors in the engine. The interpretation of the meaning of the aural alert beeper, that is, which sensor was causing the aural alert, was left to the operator to infer, based on the cadence of the sound and the circumstances that existed when the aural alert sounded.

Typically a continuous tone aural alert would indicate an overheat condition.

Usually the operator's manual would clearly describe all the possible circumstances that could cause the aural alert to sound, and indicate some means of identifying the meaning of the alert based on some characteristic of the sound cadence or other the circumstance of when it was activated.

If your c.1992 Mercury 150-HP engine is a two-stroke-power-cycle engine and if it has an automatic mechanism for mixing lubricating oil with the gasoline fuel, you can find very detailed information about this system in an article I wrote in the REFERENCE section of the website using excerpts take directly from the Mercury Service Manual. See

Mercury Automatic Oil-Gasoline Mixing System

There is no oil filter indicated in the illustration that shows all components of the oil system.

Cvin wrote:Q2: could the sensor that is located a the bottom base of the oil filter be the cause of an aural alarm?

The general purpose of any electrical sensor on the engine is to initiate an alert to the operator if the sensor detects something abnormal. So on that basis, just about any device on the engine that looks like it could be a sensor is certainly very likely to be able to cause an aural alarm.