Hi guys

My wife has been using my 2005 E320 CDI while I am repairing her 1999 E200D

While driving on the highway a red message displayed briefly “ Reduce engine oil level OR reduced engine oil level”.

She is as unable to discern whether it said reduce as in remove done if the engine oil OR if it stated Reduced engine oil meaning that the oil was low,

That said, I changed my own oil about four months ago and have not until yesterday receive and oil level alerts.

Now, I attempted to research what the oil level should be if using a dipstick and found varying opinions. So prior to draining the old oil I used a curtain rod to measure the existing oil level and marked it at approximately 6 1/2 inches.

This morning prior to rushing off to work I did the automatic oil measuring procedure that displays on the dash and it said ok.

Nevertheless, my intuition told me to add about a quart and so I did,

She drove the car today, received the same message in red and after pushing the reset button later received 3 of the same message but this time in white.

I got home tonight, removed the cover and used my homemade dipstick that was previously marked st about 6 1/2 inches and in my opinion it it over an inch lower which should equate to at least a quart of oil low,.

My common sense tells me based upon the dipstick reading that the oil is a bit low despite what the car is stating.

I gind it hard to believe that the oil level sensor is telling me to remove oil when it appears to be lower on my homemade dipstick

Any advice Wilber greatly appreciated