Driver 1.8 Oil Problem
 

I've recently bought a 1996 Golf Driver 1.8 (Petrol) and which has been running perfectly. However, I went out for a spin the other day and did some fast motorway driving in fifth gear. After about ten minutes the oil light went on, with the buzzer sounding. Rather worrying!

I kept driving along for a bit, only to realise if I revved over 3,000 rpm the light & sound would go out, only to come back temporarily a few minutes later. Which made me think there's a connection between the rpm and the oil light ?

As recommended by my garage, I'm using oil 10w40 Synthetic oil. Is that okay ?

Other than that one time motorway driving, I've had no problem whatsoever with the car. Brilliant car. Just I'm gonna be doing a-lot of miles soon, and wish to get this sorted.

Any help would majorly appreciated!