Idle / oil pressure

[Vin-Man]

At what RPMs should I idle? It's at about 500.

My oil pressure at idle is about 15-20 pounds. It is at about 48-50 pounds at higher rpm. I just had all new valves put in, and I don't recall seeing the drop in oil pressure at idle before and was wondering if that is normal?

 

[jeev]

My RPM's are set at around 700, that gives me the best idle. Are you getting a smooth idle? Your oil pressure is good, a drop/rise in pressure is perfectly normal with a change in RPM's. As your engine is moving faster more oil is moving through the system causing the increase in pressure and vise-versa when the engine slows.

 

[TJK74]

The drop in pressure at Idle is normal. at 15-20 at Idle thats reasonably good. As long as is goes up when running off Idle you should be good. Above 35 is good. On my 351 its 25-30 at idle and 55-60 with the rpms up.

 

[Vin-Man]

It's not really smooth, It wont die, but I tink I'll try to get it up to about 700 like you said. I held the trottle at 1000 and that seemed to fast. I forgot to mention its a 302. It holds right at 50 at higher RPMs I was just worried about the drop to 20 at idle. Glad to hear thats normal. Thanks guys.

 

[Jolly66]

Oil pressure: I read 40 at idle and 57-60 down the road. Comparingly it looks like i'm running considerable higher than others. its a 289ci

 

[hakstooy]

Weird. My 302 idles at 40-50 but drops to 30-35 at speed.

Is that bad??:?

 

[wildbill]

;D ;D ;D ;D If you read the book they DON'T give a idel pressure its at 2000 RPM so you are good to go and as far as idel go's 650 up works. It will depend on the cam and that ect. Mine works best at 950 or it gets lumpy;D ;D ;D Bill %)

 

[76 explorer]

your oil pressure sounds ok unless its steadily declining over a period of time. mine runs anywhere from 40 to 60 but usually is at 50 after warm up unless its over 90 degrees outside... not sure what idle is supposed to be as far as the books go but i just idle mine down as far as i can and it still be smooth... i have an auto but in drive i have mine set at about 525 and i believe in park its set at around 600

 

[74bronc]

ballpark guidelines in the automotive industry are 10 psi for every 1k rpm's. Your oil pressure is fine. Wouldn't worry about it at all

 

[Bronco Sport]

Oil pressure: I read 40 at idle and 57-60 down the road. Comparingly it looks like i'm running considerable higher than others. its a 289ci

That's the same as what my stock rebuilt 289 runs at too.

 

[Dez]

My oil pressure starts off at about 40 upon start up but after it wams up it goes to about 30psi at highway speeds and down to about 10psi at idle. This is a little disturbing but it has been like that since I've had the truck and has always run fine.

My idle is at about 800-900 with EFI.

 

[Broncobowsher]

My oil pressure starts off at about 40 upon start up but after it wams up it goes to about 30psi at highway speeds and down to about 10psi at idle. This is a little disturbing but it has been like that since I've had the truck and has always run fine.

My idle is at about 800-900 with EFI.

The 40 PSI is at startup because the oil is cold and thick. As it warms up, it gets thinner. Anyone who had squeezed in a bottle of gear oil on a cold day and again after leaving it in the sun on a hot day will realize what effect heat has on oil. You are still above the 10 psi per 1000 RPM rule of thumb, but not by much. probably some worn bearings. The band-aid, winter time oil pump driveshaft killer is going to a thicker oil such as 20W50. Good trick in the summer, but can be death in the winter.

 

[Dez]

This is something I'm keeping a close eye on. I just hope the engine can last until I can afford to slap a new one in there. I have faith in her though.

 

[Broncobowsher]

I have seen some dog tired engines run with practically no oil pressure for a long time. Just don’t have the power to hurt themselves. Freshen the engine up with some new heads and fresh carb and the bottom end just falls out.