No oil pressure at idle

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indirect_connection

indirect_connection

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Recently fixed the wiring to my oil pressure switch and was dismayed to find the oil light glowing at idle. I removed the switch and placed a mechanical gauge, and it confirmed. Basically zero oil pressure at idle. Comes up to about 5psi at 1500, and climbs from there. Snapping the throttle got me 40-50 psi.
I changed the oil/filter and it made no difference. (No glitter came out either).

Engine is a overhauled Magnum 360. I hadn't noticed any engine noises that would lead me to believe it had oiling issues. Main and rod bearings replaced and plasti-gauged within specs. Cam bearings were not touched when the lunati roller cam was installed. Oil pump is stock Magnum, I just took it apart to check for scoring on the rotor (looked ok). Summit oil pan and pickup (I didn't use Teflon tape on the pickup threads, was I supposed to?). Stock magnum oil pump drive. Wix 51515 (tall filter) and 10w-30 oil.

Anything I can check before I have to pull the motor?
 
might be a little low. every stock mopar i ever owned runs about 5psi at idle when warm, fresh or not. i used to not like it either, finally gave up. how much pressure do you want at idle?
 
Have you hooked up a mechanical gauge to double check the pressure?
 
Oil pickup pushed against bottom of oil pan can cause oil pressure issues.
 
All pressure figures given were with a mechanical gauge tapped in by the distributor. My car doesn't have a gauge, only a light.
 
It was just a thought, I don't really trust the electric OEM gauges.
 
So is this is a first start of an overhauled engine?
If it is and you're using the stock oil filter mount. You know the threaded nipple and round plate with the holes in it. Anyway, remove filter, nipple, and round plate. there's a threaded hole under this plate that's supposed to have a pipe plug blocking it. If it wasn't replaced after cleaning block the oil pressure will be just as you described. The good news is you probably didn't damage anything. But stop driving it till you fix it!
 
indirect_connection said:
I used a boroscope in the drain hole to check that, couldn't really see. I figured if that was the problem, it would affect more high rpm vs idle, but I could be wrong.
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I figured you could check the easy stuff first.
 
I think there are a couple of plugs on the front of the block as well.
 
sccachallenger said:
So is this is a first start of an overhauled engine?
If it is and you're using the stock oil filter mount. You know the threaded nipple and round plate with the holes in it. Anyway, remove filter, nipple, and round plate. there's a threaded hole under this plate that's supposed to have a pipe plug blocking it. If it wasn't replaced after cleaning block the oil pressure will be just as you described. The good news is you probably didn't damage anything. But stop driving it till you fix it!
Click to expand...
I've got maybe 100-200 miles on the overhaul. The block was not hot tanked, and I didn't remove any plugs.
 
Fill us in, how far did you tear down the block for your overhaul ?

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My 67 dart, 273, 150,000 miles on 1st rebuild 319,000 total miles,

Would turn on the 8 psi (or is it 11 psi???) Indicator switch when the engine was at operating temp on 10W-30

Now I run 10W-40 oil and don't have that problem any more
 
Dana67Dart said:
My 67 dart, 273, 150,000 miles on 1st rebuild 319,000 total miles,

Would turn on the 8 psi (or is it 11 psi???) Indicator switch when the engine was at operating temp on 10W-30

Now I run 10W-40 oil and don't have that problem any more
Click to expand...
Scary thing is it didn't show any pressure at idle with the fresh (cold) oil either.
 
rklein383 said:
Oil pickup pushed against bottom of oil pan can cause oil pressure issues.
Click to expand...

How? That's how it's designed. Look at one. It's design is such that it's supposed to rest against the pan bottom. Resting it against the bottom is how NOT to lose pressure.
 
I am having a bit of trouble trying to determine the level of your rebuild. Was the crank turned? were the cylinders Bored and honed? were the heads rebuilt? were the cam bearings changed? If not, I would call it a refresh. If a crank is not turned, that could easily be the cause of your low oil pressure.
 
harrisonm said:
I am having a bit of trouble trying to determine the level of your rebuild. Was the crank turned? were the cylinders Bored and honed? were the heads rebuilt? were the cam bearings changed? If not, I would call it a refresh. If a crank is not turned, that could easily be the cause of your low oil pressure.
Click to expand...

A friend of a friend used standard bearings on a .010/.010 crank. It actually had some oil pressure until hot and then it plummeted.
 
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