QuestionI need to know the oil pressure specs for a Chevy Pick up 1500 4WD 5.7Ltrs
AnswerThough you did not list a year, the numbers are pretty much universal.
First of all, oil pressure is a derived unit of measure. Pumps produce liquid flow and resistance to the flow is called pressure. Resistance can vary by the type of oil, the temperature of the environment, and the condition of the engine.
Generally, 30 to 75 pounds per square inch (psi) of oil pressure is considered "normal." A cold engine may show 75 psi or more when first started. At idle, with a hot engine, the pressure may be 20 psi with conventional motor oil. With a synthetic oil, it could be even less.
At 35 mph or aboove, 40 to 60 psi is considered "normal."
If the readings seem high, a plugged oil filter could be causing the reading. The engine will bypass oil around the oil filter at high pressure to ensure that oil flows to the moving parts. This can sometimes be seen by the oil pressure needle bouncing when the engine is started cold because the oil pressure will cause the bypass valve to open and close until the engine warms up and the oil thins out.
If you are reading an electric oil pressure gauge, keep in mind that they are known to be inaccurate. A known good mechanical oil pressure gauge should be installed to check any engine where oil pressure readings are suspected to be low.
If your engine just has a warning light and it comes on, you need to verify that you have adequate oil pressure. Many of the sensors for the warning lights do not turn on until the oil pressure drops to about 8 psi. Driving a vehicle with oil pressure that low will cause serious engine damage.
