Oil Pressure

[Green544]

2005 Pathfinder V6 (4.0)The oil pressure gauge fluctuates once the engine is warmed up. The vehicle drops to about 500-750 RPMs while stationary at a light and the oil pressure gauge drops to about a quater in the normal range. Once the vehicle's RPMs increase and the vehicle is motion the oil pressure gauges goes up to the half mark on the normal range. Is this normal for the pressure to fluctuate that much or is something starting to go wrong with this vehicle?

[Vegascorbin]

Yes it is normal UNLESS this is something that just started and had never done before.

It is normal for an engine at idel to have pressure as low as 10 to 20 PSI and as high as 50 to 60 PSI at crusing speeds.

Generaly if you keep up on the oil changes and do not abuse the engine you will be fine.

Keep an eye on the low end of the pressure. When you see it start to drop lower than normal you should change the oil no matter how long it has been from the last change. It is one sign (of many) that the oil is starting to brake down.

Best answer is to install an aftermarket pressure gauge that reads PSI and then you can check the Factory service manual for what the pressure should be at what RPM.