Low oil pressure makes me nervous

dibbons said

and the 40 Wt. is reading between the second and third graduation at idle when first starting up. When fully warm at idle, the pressure drops all the way down to halfway between the zero and the first graduation. And that does not bother me, but climbing the grade the other day at "full speed" with the same oil pressure as hot idle pressure is what made me nervous and the reason I started this thread in the first place.

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The straight 40W is acting exactly like it should. If you put in 10W40, then the pressure would not be so high when cold but would be the same when hot. If you want higher pressure at hot idle after climbing the long grade, you'll have to go to an Xw50 grade. Or try an Xw40 pure synthetic to get a bit more pressure stability.

Ultimately, it sounds like: the oil pump is somewhat worn; it ought to keep pressure up much better at road RPM's with straight 40W. No wonder you need the 25W60 or whatever.

Or the pressure gauge is off....which has been said how many times now? LOL Figuring that it reads 'such and so' at certain gradations is meaningless; the gauge moving around means that that the gauge resistance winding is intact and that the sensor is working, but little more.

And BTW, I am not aware of 5 psi being an actual minimum pressure 'spec'.... it is just where the idiot light comes one.