2000 Oil Pressure

I have a 2000 5.3L Sierra with 124,000 rounds. Lately I have been noticing that my engine oil pressure seems to be much lower than normal. When at operating temperature, the oil pressure at idle never used to drop below 40. When cruising at 60mph, it was usually around 55psi to 60psi, depending on outside temp.

Now, however, once warm, the oil pressure will drop to around 25 psi at idle, a substantial drop. I realize it still falls within the normal range but has dropped noticeably. I live in MN and it gets really cold here in the winter so it should be higher than normal.

Anyway, is this a oil pump issue or something else???? I have noticed to that at cold starts idling, there is an odd whirring noise less faint than a belt squeel. I have been searching for oil pumps on the net and they are scarce to say the least. Anyone else have this problem and a solution for it??? Please help. I have heard way too many times that if it is in the normal operating range not to worry. However, it seems odd to me that it would be dropping like this. I don't want to wait until it fails to fix it. PLEASE HELP ME!

Get a mechanical gage on it at the oil press switch port and confirm these dash gage readings first.

I agree with you.. you know your truck better than anyone. If it is not normal for what you are use to, better to have it checked out.

http://www.partsamerica.com/ProductList.aspx?parttype=151&searchfor=Oil+Pump&ptset=A

I found oil pumps for about $100-$200

Good luck

Get a mechanical gage on it at the oil press switch port and confirm these dash gage readings first.

I agree, could be a bad sending unit telling the computer lies. Don't spend money on parts with this one until you've tesed it.