anitasahoo

I have the exact same problem with my 2018 Audi Q5... did the thicker-grade oil help? After the oil-pump was replace and the light was still going on, the Audi shop is saying that indicates there is engine damage, I only drove 5 miles after the first time the warning went on at a stop light, and then happened again at the same light the next day. Hard to believe there is engine damage when it was/is driving fine. I feel like I am being taken by the Audi shop for 8-12k to replace the entire engine. A friend who deals with cars thinks maybe just changing the oil to a thicker-grade, atleast worth a shot before pouring any more money into the car.

S4'ed

Assuming the oil type/viscosity is correct, and the oil filter is OEM (Mahle, or Mann), the oil pressure switch (es) are good, and the PCV unit is good, then the most likely cause of hot-idle low oil pressure are the balance shaft bearings, not the camshaft (or crankshaft) bearings.

rdA4WtQ5

Maybe this?
Let's hope.

Bteux0611

I'll second that, it's the balance shaft likely the intake side one that's wearing out and that's where you are getting less than 18 psi at idle. On a warmed up engine usually after driving for a half hour.
The light trigger's at 1500 rpm and less than 18 psi. Typical idle on warmed up engine should be about 22 at least. So hook up a mechanical gauge to find out. I've worked on hundred's of these engines and have seen this many times. So the balance shaft will eventually Lock up. The head and rod bearings will likely be fine.To avoid lock up and extend engine life, make sure to rev it up to build oil pressure when that light comes on. I've been doing this on my personal car and a customers car for over a year now. So don't let it idle long after driving for awhile. Replacing balance shaft has fixed this on a number of cars for me. But it's also a big job.