I have an Audi A4 avant 1998.
At first when I went in 4 or 5th grear the red oil lamp starts blinking when I was above 1500 RPM and below 1900 RPM. This is because bad oil circulation.
After changing oil the result was 1500-1700.
After using motor flush and changing the oil and filter it only flashed at 1500-1530 or so..
I also changed the oil pressure indicator but it didn't help.
I use synthetic 5W-40 oil.
The lamp dont start flashing below 1500 rpm or at low speeds and only after about 7 minutes or so from starting the motor.

 

Hey guys new here having troubles of my own. Mine are unlike everyone's that I have red. My 02 1.8t keeps giving me a low oil pressure warning. I changed the oil pressure switch made it worse? Checked oil pressure manually and all looks good. Fresh oil full synthetic. After knowing my pressure is good I've put about 1,000 miles on it with the pressure light still coming on and going right back off but no motor issues what so ever. Another thing is light only comes on for a half second but only between 1,500 and 2,000 rpms after get higher or lower then that goes right off. Help please!!!

 

Hi,

I also have the red oil pressure light coming on with a ding. When the oil pressure light comes on the tappets get noisy, so I do believe the warning. Here's my troubleshooting so far:
1) I ran engine cleaner through the vehicle, and added new oil and filter. It ran fine for 30 Kms then flash/ding again.
2) I have replaced the oil pump and pickup, new oil and filter. Tested with a pressure meter at cold and pressure is fine. It ran fine for 30 Kms then flash/ding. Please note that the oil pressure was not retested at this point with the light flashing (the mechanic messed up here, hey?).
3) More engine cleaner, new filter, new oil. It ran fine for 30 Kms then flash/ding. (I heard that it could need a second dose the clear any sludge).
4) Here's the interesting thing.... I took a couple of litres of oil out of the sump and poured it back into the top. It ran fine for 30 kms then flash/ding. Another 2 litres out of the bottom and into the top and the same thing - I get 30 kms out of it and then the oil pressure light comes on and the tappets go noisy.

Please.... does anyone have any idea what this could be? Please note that when I say 30 kms I am not saying 15 minutes... it doesn't matter if I leave it overnight.... it's around 30 kms of engine running time.

This has completely baffled me and every mechanic that I've spoken to. We've changed the pump/pickup/oil/filter/desludged... and yet it's fine for 30kms when oil is poured into the top.

 

I am getting the same issue, I suspect its either a blocked oil pickup or the cam follower in the HPFP.

Did you figure out a solution to the problem?

 

and could last mins or days

 

I had same issues with my S3.
This is caused from sludge build up in my case.
My solution if oil levels were good at time of getting warnings.
Drive to nearest petrol station.
Put 1/2 L of diesel into oil filler, Take a easy drive home, Mine was 25 Mile.
Drain oil and refill with cheapo oil and another 1/2 L of diesel.
at repeat.
remove sump, clean all crap out, replace oil pump, pick up and filter.
fit fresh cheapo oil and do 500 miles, during this stage the light should be off.
Drain, change filter and refill with quality oil.

 

i would not be supprised if it is some sludge in there, but I am changing the pump Nox Vidmate VLC and filter and so on and cleaning both the oil tray/pan (whatever the english name is ) When I get it off.