Oil sending unit replacement 1989 chevy silverado 4x4 350cid

Question edited for clarity.
Question moved to model category.

If you have a 4.3 or 5.7 Litre engine (Silverado Classic Body Style), it is mounted on the back of the intake manifold in a brass fitting just under where the fuel lines come up from the transmission bell housing.
Jun 4, 2013

I have a 2007 chevy silverado and need to replace the oil ...

By the time you hear noise from the engine it will be too late for that engine. You may need an oil pump replacement. Have a mechanic check the oil pressure. It's cheaper than replacing the engine.

Put a gage in the sending unit hole and see if the oil pump is weak, that is the best way to tell if the engine pump is ok.

Have you ever replaced the fuel filter?

Were is oil sending unit on a 1998 chevy z71 silverado 5.7 liter? Oil pressure is dropping to 1/8 of gauge

check the filter,, if its bad enough your oil won't pass through it, making it look like your oil is full, but its not moving, Chevy's have whats known as a stepper motor also on the oil gauge,, whats bad about that is if thats gone bad, you have to replace the whole gauge cluster which last time I checked is 250.00

You probably need a oil pressure sending unit it is located at the back of the engine and is a high failure

the oil pressure sender unit tip is got sut build up remove it, clean or replace it. when oil is thin it gets right in but while its cold and thick it wont trigger the sending unit. causing light to come on.

the oil sending unit is located at the back of the motor right below the rotor cap it is about 3 inches long and has a 3 wire plug hooked t it

most likely the problem is the oil pressure sending unit or the oil passage to the sending unit is partially plugged, that is unlikely, I would replace the sending unit 1st.