A pressure gauge indicates actual pressure and a differential pressure gauge indicates the difference in pressure.
A boost gauge in an internal combustion engine has the role of a pressure gauge. The gauge indicates the manifold's air pressure or a turbocharger or supercharger's boost pressure.
It means at least one of the gauges is out of its normal range. The "check gauge light" is notifing you to take notice with either the engine temp gauge, the battery gauge or the engine oil pressure gauge.
THE NORMAL GAUGE PRESSURE SHOULD STAY AROUND 12 TO 19 P.S.I
If your oil pressure gauge is high you have to much oil in your engine. Overfilling your engine can result in you blowing out your gaskets.
Oil pressure has to built up. As long as the pressure is normal and the oil level is good. There is no problem.
Check with another gauge. If still 0 when warm, the engine is worn out.Check with another gauge. If still 0 when warm, the engine is worn out.
If you problem is that the gauge shows oil pressure with the engine off, you have a gauge or sending unit failure.
Check with manual gauge - if pressure normal - could be defevtive oil pressure sensor or gauge
i have a 1993 190E - my oil pressure gauge always sits on 3. ==New Answer Haedline == The oil pressure gauge actually moves but is related to several factors Engine Temprature Oil viscosity Engine speed. When you start you car the engine temperature is low the gauge goes to 3, after a long drive/travel and if your temp gets to 80C then with an engine speed of 750-800 RPM you oil pressure gauge will read about 1.5. if you rev. the engine the pressure gauge goes up to 3
Oil level and oil pressure are different. You don't need to have full oil to get normal pressure.
As the engine speed increase so does the speed of the oil pump. the faster the pump turns the higher the pressure becomes. When changing gear the engine speed drops along with the oil pressure.