Oil Pressure?

[04SILVRADO]

When you truck is warmed up, what is your oil pressure reading at idle? Mine is about 30. I thought it use to read about 40. Maybe I'm wrong. The mechanic at the dealership said that it is still normal operating range. I have a 2008 Silverado with a 5.3.

Thanx,

Matt

[georgecdisc]

Just above 40 while cruising. Probably a little below 40 when idle.

[Draenor]

30-60 is normal. Using a synthetic can drop it a bit more than the 'norm' which is around 40.

[pm26]

For comparison, I will share what the oil pressure gauges in Older Mercedes cars show (mid 80's models, both diesel and gas). The gauge reads in bars. One bar is a unit of pressure equal to approximately 15 psi. Bars are often used as pressure units in geology and study of explosives where very high pressures are encountered and expressed in kilobars (1000 bars).

 

At idle these cars typically read 1.5 to 2 bars (22 to 30 psi). As soon as you hit 1,200 RPM the needle on the gauge pegs out to the full range, which is 3 bars or 45 psi. The 1,200 RPM is that magic RPM where the oil pressure increases to maximum and stays there at higher RPMs. As long as this happens you know you have a properly operating oil pump.

 

According to Mercedes specs, the idle oil pressure should not fall below 0.75 bar at idle. I have never seen it drop that low.

 

BTW, Mercedes built very sturdy engines back in the 80's. All of them, gas or diesels, have 8 quart engine oil capacity for a maximum reserve. Diesel cars also have a thermostatically controlled engine oil cooler, which is a large radiator like unit bolted to the left side of the radiator.

The sad truth is, nobody builds cars like that anymore, not even Mercedes. (At least not in that price range).