i have a 2005 a4, 1.8t quattro, and i've had it for about two years, and its been great so far. the other day the red oil can started flashing, so i pulled over, checked the oil, and everything was fine there. i brought it to my mechanic on monday, and he replaced the sensor to see if that was it, and manually tested the oil pressure. i believe he said that the idle was at 14psi and running was around 45psi, which were both below spec, but still working. is this something that an engine flush could fix? i want to try anything i can before i have to bring it to the dealer and spend and unnecessary amount of money. since i've had the car i've only put in synthetic oil, and changing it around every 5-6k.

 

No, search oil sludge, there is a world wide TSB for 1.8T engines on the A4. It may be covered by audi if you can show proof of oil change receipts, call your dealer for details on the TSB.

If they won't cover it, drop the oil pan and replace the oil pick up tube and oil filter.