Oil level problem with 2005 Audi A6 3.0 TDI Diesel Quattro

My 2005 A4 3.0 convertible audi is not a diesel, but I had a similar experience with a low oil signal going on and after checking the oil, which was sufficient, and replacing the dipstick, the light did not come back on until a subsequent trip. The light usualIy went on when I was close to the needing an oil change. I've had the car, a used one, for about two years, and the oil light minimum signal started behaving like yours early. About a week ago the oil pressure warning light came on. I don't know if there's a relationship, but if there is be careful. Audis of our vintage have a problem with sludge build up that damages the oil pump, which is a costly item. If you drive the car with low oil pressure you may seriously/fatally damage the car. I don't know if the sludge, if that's what you have, can be cleaned out, but I'd do it if it can be. My mechanic advised me to trade the car to a dealer rather than fix it. Hope you have better luck!