Low oil pressure

Beubank · February 28, 2006

My 1993 Chevy truck dropped oil pressure down to "0" on me the other day at a stop light. At RPM it was around 20 or so but when I let of the gas it plummeted. I checked oil and it was low so I went ahead and changed it and the filter. I thought it was fine and then I went to the store and back and by the time I got back it fell again at another light.

The truck has 180,000 miles on it would my pump be going bad or is it just in need of a rebuild?

Thanks for your help.

RI1994 · February 28, 2006

My 1993 Chevy truck dropped oil pressure down to "0" on me the other day at a stop light. At RPM it was around 20 or so but when I let of the gas it plummeted. I checked oil and it was low so I went ahead and changed it and the filter. I thought it was fine and then I went to the store and back and by the time I got back it fell again at another light.

The truck has 180,000 miles on it would my pump be going bad or is it just in need of a rebuild?

Thanks for your help.

<{POST_SNAPBACK}>

Try changing the original guage to a mechanical guage for more accuracy first.

PaulQ · February 28, 2006

Is your oil level still good or are you losing oil. I don't think it's your oil pump because I don't belive the oil pump has any influence on the pressure. With 180,00K it could be quite a few other variables. Are you blowing any smoke out the exhaust or do you hear anything in the motor.

Beubank · February 28, 2006

No smoke, I was probable 1 1/2 quarts low before I changed it. The engine sounds like it has when I bought it. Nothing out of the normal. It was a work truck before I bought it so you never know what you are getting but it was cheap.

Beubank · March 6, 2006

Just an FYI if anyone has this happen to them. I went to put on a mechanical gauge and when I pulled off the wires to the oil pressure sending unit there was oil in the wire fitting. So I changed out the sending unit and put a t fitting in for a mechanical gauge. Went and tested her out and oil pressure light didn't come on and the gauge held around 8 on the sending unit gauge and around 12 on the mechanical gauge this was at idle around 18 (OPS) and 25 (mech) at driving speed.

stumpy · March 7, 2006

At work today, for you that don't know, I work at the used car department at a chevy dealership, we had a 96 gmc surburban, It only has 80,000 miles on it. It was reading really low psi. But my boss has been around for years, and knows these stock gauges can misread after a long while. It was almost at 0 psi at idle, but the engine sounded fine, the oil was fresh and just recently changed and full. So you might just have a bad sending unit or guage.