Hi Job, I'm not sure if I can answer your question accurately, but thinking about the oiling system I try to draw some conclusions. Other than the oil pan itself, the filter is located at a very low point of the entire system. If the filter has no design to prevent drainback, any oil in the system will eventually settle near the level of the filter due to the force of gravity. It's possible that a filter with a check valve (anti drainback valve) can prevent some of the oil that is in the upper part of the system from draining to the filter, and thus, into the oil pan. The filter with a check valve should be able to keep the oil passage full up to the front camshaft bearing, making pressurization very quick upon engine startup. Devon
what about cannister type filter elements?i just bought a napa gold filter for my 55,does it have the anti drain back?and is it a good filter?thanks donny
the oil filter is made by wix and wix manufactures good filters. i ise them on all three vehicles. chances are your filter will not be anti-drain.
All the anti drain back valve is, is a circular rubber flap behind the outer holes of the filter. It is easy to see if you look at the filter. I run a reusable System 1 oil filter. It has an anti drain back valve that is removable. I tried it both ways. I didn't notice any difference in the time to get oil pressure on start up. System 1 told me that it adds some restriction to the filter, so I have left it off for the last 8 years.
So a new filter will not solve the problem. After 4 to 5 day it takes about 7 Sec. before the pressure comes up.
You can buy an oil pressure cut off switch from summit racing and wire the ignition through it so the car will not start until it has oil pressure.. I bet it has pressure before you see it on the gauge..
Are you hearing any bearing knock while you are waiting for the pressure to build? Is this a mechanical gauge or light?
I would try an anti-drainback filter anyways, it might help. If it doesn't you are only out the price of a filter. 4-5 sec after a car has been siting for a few days before oil press is up isn't out of the ordinary, there will still be an oil film on the bearing sufaces etc. so as long as it isn't revved there shouldn't be any damage.
The purpose of the anti-drainback valve is so the pump doesnt have to fill the filter before oil reaches the rest of the system. The rest of the oiling system will drain, leak, drip out any remaining oil after shutdown due to the machined clearances, like Larry said, if your not hearing any banging or knocking noises on start-up, your fine, just dont rev it, be easy on it till pressure builds.
I think if you look at most filters, there will be an anti drainback feature. The AC filter has one. Most filters I have looked at have one also.
MY suspicion is that the suction side of the oil pump (pickup tube and block passage) is draining; and the pump needs RPM and time in order to re-prime. Trouble priming would account for the few seconds delay between engine start and oil light out. Any scoring of the oil pump housing or end plates? Acceptable clearance on the oil pump gears?
Yes it's a Ac filter, but all oil gallerys are up going, so in my opinion the filter never can drain back. Oilpump is new, with the boosterplate, right clearences, TA oilpressure regulator etc, and it's also a HV..... No noises, engine runs fine, only after startup a short tikking of a lifter till the pressure comes up. I have 2 gauges. One mechanical and one (stock) electrical. Both comes up at the same time.
It sounds as tho you are ok with the pressure even tho it takes a bit, its normal for a lifter or lifters to tick a bit until pressure builds, also, dont run a super thick oil, heavier oil will take longer to circulate than thinner oil. Also remember, engines with external front mounted oil pumps (Buick, AMC, Big block Mopar) have to suck oil up the suction tube, travel to the front of the block, thru the convoluted passages in the pump, thru the filter, then pressurize the rest of the oil passages. Chevy, Olds, Ford, and others have the oil pump right in the pan, so start up pressure is almost instant, the oil doesnt have to travel as far to reach the pump.
Did a little test today, now after 4 days I removed the Ac-Delco filter and it was totally empty. No oil in it..nothing. So the filter does drain back!!!! Let the wife start the engine (without ignition and the filter still off) and in a second saw the oil coming. So the Delco filter sucks I try a Wix filter and hope it doesn't drain back. Ta-performance recommended also Wix filters. One question about my oil filter housing. What is the meaning of the little black valve at the top of the housing.
That small valve is called a "oil filter bypass valve" which allows oil to circulate through the engine even if the filter is partially or fully clogged with debris. Not to be confused with the oil pressure relief valve. Devon
Hmm, I find this to be very strange. I've used quite a few PF24 filters and they always hold PLENTY of oil. Sometimes my oil light goes out before the motor is even started. I still stand by my past experience, with a NAPA filter taking considerably longer to put the oil light versus a Delco. :bla:
I've had very similar experiances with AC filters a couple years ago, I'd change the oil, and the filter would be completely dry, no oil ever circulated thru it, you could still see the shiny metal inside, never found out why or how this was happening, very strange
And you'll want to inspect it CAREFULLY, I see too many of them with a chunk of debris in them, blocking the valve open. Takes only a moment to tweeze the piece of debris out of the valve.
X2. You can gently push it off it's seat and spray it with a little gumout. I do that at oil changes.
