Overtightenin the tube is a interesting thought. If that is true then that may be a problem. Is it possible for the pressure relief in the pump to be faulty? If it was stuck partly open could that produce the low pressure?

Durham Missouri

The relief valve can be faulty but it seems like it would be low pressure at all RPM, not just idle and immediately jumping to 45psi off idle.


Lawrenceville, GA

"What would be the cause for low oil pressure at idle. Its went from 20lbs to 7-10lbs gradually over the course of a few weeks. I still have good pressure(40 lbs) at cruise and around town. The engine only has about 3000 miles on it so I dont think it's a wear issue. I will ad that when cold it has 20+ idling."

What was the reading(a) at break-in?

Interesting Read - http://www.eatonbalancing.com/2014/09/19/hi-volume-oil-pump-for-the-y/

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Just a thought but could the end of summer and onset of cooler weather be a factor? Would multi viscosity oil show a difference at idle in colder weather? 

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Years ago when I wrenched for a living, Pontiac's were semi notorious for the relief valve sticking in the open position. Idle pressure went to zero but cruise pressure was normal.

Dave

Right now I'm leaning toward putting a new pump on it if the gauge checks out. Hopefully that cures it and I can get back to driving it. It seems like every year something comes up and I have to park it early for winter.

Durham Missouri

Every y-block I've owned (20) had low oil pressure at idle, as long as there is some pressure at idle there usually is no problem.

Maybe I'm worried about nothing. It was just a little concerning since it started out around 20 at idle and now its 10. I know 10 psi is sufficient at 700 rpm. I'd just like to get it back to where it was for peace of mind.

Durham Missouri

A sudden drop like that is something to worry about.


Lawrenceville, GA

What brand of oil pump would be reccomend? I'm thinking of getting a Melling.

Durham Missouri