Oil Pressure

[madmustanger]

Madmustanger here : my 85 gt vert 5.0 had a extra low pressure reading after trip to tobacco shop in chester's walmart it has the usual idiot guage but at idle after i got back home bottomed out for bout 10 min the slowly came up to about 20 --30lbs on a mechanical guage.oil's a litte over due for change cause place i was having shut down.
What i need to know is roughly what the pressure reading would be for a high milage 5.0. Idrive her hard would appreciate any thoughts on what it should be at this time in her life. I'm a former dirt trackerand street racer/dragger thx for your ideas on this I'm on ss disablity so can't jump into big changes very easy and sorry if this is in wrong forum area

 

[squeak93]

Seems odd to bottom out and slowly come back. I'd suspect something more than a sending unit causing problems.

 

[elarm1]

I would change the oil and maybe flush it some kind of way. Could be oil pump going bad but it can be replace while motor is in car. Oil pressure should be around 40-50

 

[Boosted92LX]

What you very well may be experiencing there since you are "over due for an oil change" is low oil level. If you don't stay on top of your oil level in an older car, (they use/burn/leak oil) you can end up with a low enough level for your pickup tube to suck air...especially if you are low on oil and drive through a dip or incline like a driveway. I've seen lots of high milage 302s with 20-30 psi.. not really optimal.

 

[powerstroke987]

sounds like the pump getting air and dropping the pressure for a few seconds, but that should only last a few seconds not minutes, and can be from low oil as mentioned but also from too much oil, too much oil allows the crank to smack the oil in the pan and act as a blender like when the wife makes a smoothy. was it bottomed out 0PSI or was it just low like 5-10PSI ? was the pressure fluctuating? only at idle ? did rpms change pressure or any other info you can tell us?