I'm on my honeymoon in Daytona Beach 1,000 miles from home. My 97 A8 with 224K miles suddenly has a flashing oil can light on the dash. It came on while in heavy traffic and stayed on until I shut the car off to check the level. It's full of oil. Started it back up and now it comes on within a couple minutes of starting the engine, there are no unusual noises or ticks and the light stays on whether at idle or over 4K RPM. I did have to replace the oil pressure sender about 2 weeks ago because mine started leaking, I bought this one at Advance Auto Parts for $8. Do you guys think it could be a faulty sensor or do I actually have an oil pressure problem? I'm away from my garage so I have minimal tools available and no money to go to the dealer so any advice is appreciated. If I unplug the sensor will that cause the light to be on permanently or will it stay off? Thanks in advance. Also, I can't remember for sure, but I think I am running 5w30 oil (I know it takes 0w40, but it isn't always available and I've never had an issue with the 5w30 and I've always used Mobil 1).

 

Well, after it sat overnight, I drove it 13 minutes in traffic and the oil can started flashing again. I went to Tire Kingdom and let them change the oil and filter with 5w40 full synthetic (Valvoline not the Mobil1 I usually use because it's all they had). I drove it about half an hour with no more warnings. I'm hoping that fixed it, I guess I will find out tomorrow when I drive it a couple hundred miles. Seems awfully odd that the 5w30 I had in there would be able to cause the pressure to drop that much, I guess it had about 4K miles on it. Also, if it was low pressure I would assume that would be only at idle and the light would go off once the engine was revving on the interstate, unless Audi programmed it to stay on until you shut the engine down.

 

Automotive and Industrial Lubricants - Causes of High and Low Oil Pressure