AUDI OIL PUMP PROBLEM

AUDI A4 ENGINE NOISE

For the past week my sister's Audi A4 2.0L 2007 has been having issues. When it starts its engine sounds like a tractor engine but after about 15 secs it quietens down and sounds and idles perfectly normal. Ever since its engine oil and oil filter change some seven weeks ago by her friend. The "Engine oil pressure light" keeps turning on, after some 20 minutes of driving, accompanied by a beep from the pizzo electric buzzer. Thereafter  it repeatedly  triggers  unexpectedly,  actually giving her a fright every time it does. I ran a scan with VCDS and there was absolutely no sign of engine trouble or DTC from the engine. Except for ABS signal out of specification fault which is totally unrelated to oil pressure. So since there was no problem other than the engine  Engine oil pressure light that triggered daily she decided to drive the Audi in that condition and tolerate the beeping. 

I inquired about the oil that they used, thinking perhaps that if the  grade of oil was too thick, it would affect the oil flow and pressure.  She fetched the container which still had some oil in it from the garage to show me what it was and on inspecting the viscosity of the oil between my thumb and forefinger I was amazed by the crap they sell unsuspecting customers. It turned out that she bought SAE 10W/20 oil at the local supermarket off the automotive shelf because it was going cheap. The oil was so thin, it was virtually like water, it couldn't even form a drop at the end of my finger. I even asked her if they mixed paraffin with the oil and she said no. I looked at the writing on the container to see if it wasn't two stoke oil for lawnmowers but it wasn't. 

Audi A4 Oil Pump (Old Top - New Bottom)

I then knew that this was the cause of the problem. The oil was too thin and the oil pump had difficulty in getting enough oil to the cams, bushes and gears  resulting in the noise caused by excessive friction during the the first 15 seconds when started. I actually thought that the oil may be too thick, so that the  oil pump couldn't push through the required volume of oil per minute. After telling her what an idiot she was to buy this cheap crap oil, I begged her to get some VW 50300 Long Life Engine Oil from the Audi agents.  I even offered to drain the crap oil out her Audi, flush the engine, replace the oil filter and fill it with the correct oil. The VW 50300 Long Life Engine Oil does cost a lot more than regular oil put it has the advantage of 30000 km before the next change. Fortunately it costs less than VW Automatic Transmission Fluid

So after replacing the filter and filling up with the new oil, the Audi now sounds a lot better but it is still noisy. Not as loud as it was before and the duration of the noise reduced from 15 seconds to about 4 seconds. Its  going to cost her a new oil pump replacement within the next week or so, because driving with a suspect oil pump is asking for the engine to seize and heaven alone knows what that's going to cost to repair.