My wife's 1999 A3 oil pressure warning started flashing & bleeping. I checked the oil level, found it low, topped up to full, ran car no problems.

The following morning my wife called me to say the same thing was happening. I advised her to go directly to our nearest garage where they changed the pressure switch and filter.

Still the problem persists.

I have now got the sump removed, expecting the inlet gauze to be slugged over, but found things relatively clean (I did use a flushing product prior to draining the oil).

Oil did run from the turbo return line, but the top of the engine looks dry (looking through filler cap port).

A chain type oil pump is fitted, which I am considering replacing as the next course of action.

Questions:
Is it a straight forward job?
Does the chain easily come off the sprocket?
Can the tensioner be replaced/accessed with just the sump removed?
Is pump failure common on these engines?
Could it be anything else?
What is the best way of checking oil pressure?

Any advice welcomed!