Just installed an FR mechanical oil pressure gauge. (along with voltmeter,watertemp gauges). What should the oil pressure reading be at idle for a 1992 5.0 GT 5spd. Also what's the recommended rpms at idle.Thanks.....
don't know the exact idle oil pressure it should be around 40 lbs. i believe. someone else will verify but manual states 40-60 lbs. at 2000 rpm. recomended idle is 600-650 rpm.
Also depends on what viscosity oil you're running. With something like a 5w30 or 10w30, it'll be a little less at hot idle, whereas with a 5w40, 10w40, 15w50, or 20w50, etc, it'll be higher at hot idle.
You can listen to the Ford "specs," but I personally believe that basing your decision about whether your pressure is low or high by reading it at anything over idle gives a false sense of security.
Jeep's "good oil pressure" specs are close to Fords. My 170k+ ZJ runs 30-40 psi at 2,000 RPM, but will drop the gauge to nearly zero at hot idle with anything less than Xw50. That tells me I've got motor issues.. the 2,000 RPM test says it's fine.. which it isn't. Draw your own conclusions.
Now that you have the gauge installed, it's a great opportunity to narrow down what weight oil you really require.