I have a 1951 bug with a 25bhp engine. During warm weather and after driving for a while the oil pressure light goes on when the engine is idle (i.e. before traffic lights). When I rev up the engine a little bit then the light goes out again. It only happens during warm weather and when I drive for at least 20 minutes, so I think it is some kind of temperature thing. The engine runs fine, without strange noises or noticeable loss of torque.
The engine has fresh new 20W60 classic oil and after driven approx. 150 miles the oil level is good and the oil also looks good. I guess that
20W60 should be good enough for my aircooled boxer.
I installed a Gene Berg dipstick to keep track of my oil temperature. If the oil warning light goes on, the temperature is way below the point that the dipstick should make contact. I conclude that the oil temperature is below 230F.
Anyone knows what is happening?