erratic oil pressure

[ChevyGuy1022]

I've been watching my oil pressure gauge a lot lately. At startup in the cold winters of New Jersey it never hit any more than 65. Down here in Florida for some reason it stays somewhere around 75 or 80, topping out the gauge. At idle is the same (about 40 or so) but at idle it's never consistent, it always jumps around from about 30-45. Anybody have this happen to them before? Is it just the stock gauge being crappy or is the pan screen clogging up or what? Any info at all will be helpful. Thanks guys

[3.8 nate]

oil pressure should be read at rpm, not idle. WHen it doesn't read anything , that's when you really have a problem.

[Jerriko]

Originally posted by ChevyGuy1022:
I've been watching my oil pressure gauge a lot lately. At startup in the cold winters of New Jersey it never hit any more than 65. Down here in Florida for some reason it stays somewhere around 75 or 80, topping out the gauge. At idle is the same (about 40 or so) but at idle it's never consistent, it always jumps around from about 30-45. Anybody have this happen to them before? Is it just the stock gauge being crappy or is the pan screen clogging up or what? Any info at all will be helpful. Thanks guys

Oil is thinner in warmer climates which results in higher oil pressure. Low oil pressure and old oil filters will result in erradic oil pressure readings. When was the last time the oil was changed?

[ChevyGuy1022]

I am very meticulous about changing my oil and the last time it was changed was just last week. I switched two changes ago to Royal Purple 5w30. I've always run 5w30 so that's no different than before. Also, wouldn't thinner oil mean less pressure? I would think it would move more freely... Anywho... The filter's new (every oil change, always a Pure One filter).

[Jerriko]

Thin oil moves faster than thick oil. The faster the oil goes, the more pressure it has. Sorry, I didn't mean to assume anything about you or your car.

[ChevyGuy1022]

No that's fine... I was just confused to the principal of the warm oil. Everything I've learned in physics, chemistry, and whatever else I decide to read makes me think in weird ways and I overanalyze everything and more often than not, end up being wrong. In this case, when the car warms up, I notice the oil pressure drop. Seeing that, I force myself to beleive that warm oil can move more freely, so the force applied to the sensor is less because it requires less force to move it. But that's just one man's opinion.

Anyway... Yeah so the oil's always on schedule. Always gets a new filter. Any idea what's wrong with the gauge, or if anything is indeed wrong with it?

[ November 24, 2004, 12:37 AM: Message edited by: ChevyGuy1022 ]

[Jerriko]

It could be a number of things:
-bad sensor
-bad connection
-GM engineering