i have a 87 iroc with a 85 305 (carb)
i have good oil pressure on a cold start but lose it when it gets warmed up
i first thaught it was the pressure sending unit so i replaced it with a complete guage setup with sensor
same problem!
so i changed the oil pump and went with the melling hi-vol oil pump with a steel shaft
SAME PROBLEM
i am geting frusterated and i am about to run the car in the river !!!!!
any help would be great so i dont spend a bunch of money on the wrong thing again
but like i say i get like 70 psi on a cold start and it stays up around 25 psi wile in the higher rpms
at ilde when it is warmed up i get like 2 psi
and it recently started running like crap
thanks for the help
nick

 

Sounds to me like it's time to start saving your pennies and nickel for a short block.

 

i guess i will agree with your sig. ... never argue with an idiot

 

Yeah, I learned that the hard way.... like everything else I know...

 

Most times a good running engine that loses oil psi like that is due to rod or main bearings. And most times you can just change them if your on a budget. It will bring back your oil psi and last another few years till its time to rebuild when the rest is worn. $20-30 and a few hrs work will restore the oil psi.

Almost never an oil pump problem but a new pump can sometimes cover up for that. But if a pump is worn. you can bet your bearing are too. both work within specs when the clearances are right. If oil pumps are losing clearance..... so is your bearings.

Also bet to get to them quick so you don't start wearing your crank or ......
Bearing are meant to wear out first.