88 VW golf oil pressure

My 88 VW Golf (8 valve engine oil warning)light and buzzer goes on after the engine is hot.I have checked the oil level and it is up to the full mark. Cannot determine what is wrong

First … check the oil pressure with a shop gage . Good chance the pressure sender is faulty .

Are you using the recommended weight oil? How long and how many miles since the last change? Note: See genex’s post prior to this one. Answer my questions, but also get the real pressure tested.

Thank you, what is a shop gage?

Iam using 5/w/30 oil in the winter because it has an automatic trans.and was difficult to start because car is not garaged. Change oil and every 2000 miles ,oil is clean.

The light and buzzing is due to low oil pressure, not low oil level. This could be a harbinger of doom. The car is 21 years old, and a worn out engine is not unusual. Check the pressure with a shop gauge, which is a calibrated mechanical gauge you install temporarily in place of the oil pressure sending unit. Any shop should be able to look at it for you. If the pressure is indeed low, your probably need to have the engine rebuilt.

The engine only has 89,000 miles on it and does not use any oil. It is smooth running and does not use any oil.I shall have the pressure checked.

Yes bob, the cheapest thoughts posted here are the oil pressure sensor may be bad. If you wish to have a mechanic do it let them know the problem and request an oil pressure check to see if your sending unit (sensor is bad) or there is a different problem.

Thanks, I will check the oil pressure sensor.

There may be more than one oil pressure sensor. Some VW engines had one in the block and another in the cylinder head.