No oil during priming?

Merenth · #1 (**permalink**) 02-15-09, 12:50 AM

Got a recently rebuilt 472 in a 1970 Deville that I'm trying to get going, but there seems to be a problem... I packed the oil pump with grease before putting it back together. I'm using a priming tool and my drill to get the oil flowing, but nothing comes out under the valve covers. When I stop the drill, I can hear oil draining back into the pan, and after pulling the filter back off the pump, there's oil on both the infeed and outfeed sides of the filter, which if I'm not mistaken means there's oil flowing through the pump anyways. Any ideas on what I should be doing/checking next? I have this great fear that I'm going to have to take the whole engine back out and start all over. Any ideas would be GREATLY appreciated. Thanks!

drmenard · #2 (**permalink**) 02-15-09, 03:34 AM

you could have a oil plug missing in the oil gallery.. under the intake by the cam... there are plugs that could have been taken out and not put back. or one came out... take off the intake and run the pump to see whats going on... you could have a O ring missing on you pick-up in the oil pan...

bootss · #3 (**permalink**) 02-15-09, 10:36 AM

I'd bet on a bad or missing oil pickup o-ring!Also by pass check valve on oil pump housing
inop.
bootss

submariner409 · #4 (**permalink**) 02-15-09, 02:04 PM

Temporarily connect a mechanical oil pressure gauge to the pressure sender fitting/hole. Prime. You should see 40+ psi.

That's a 0 - 100 psi gauge stuck in the front of one of my Olds 455 boat engines specifically for priming checks.

Merenth · #5 (**permalink**) 02-15-09, 03:48 PM

Well, with the intake off, assuming the two small plugs in between cylinders 1/2 and 3/4 were the ones you speak of, there's in place there. Priming the oil pump with it open shows negligible oil flow from the lifters, with only a very small amount oozing out. Haven't actually attached an oil pressure gauge to it yet since it's actually quite a pain. I suppose I'm getting ready to drop the oil pan and take a look at the pickup. Assuming the O-ring is there just for arguments sake, what would you recommend next?

drmenard · #6 (**permalink**) 02-15-09, 04:40 PM

Make sure you don't have a sticking or stuck presure relief valve in the oil pump... these valves have been known to cause lots of problems...polish them up with some 400 grit paper and scotchbrite... make sure it don't stick...

submariner409 · #7 (**permalink**) 02-15-09, 04:52 PM

Lifters, pushrods and rockers have minimal oil flow, especially if the engine is not rolling over The lifters sit in a bore with a limited slot to the gallery....some lifters pressurize over only part of their movement stroke which is one reason they have a check valve inside to trap the oil in order to actually provide lift. If the main oil galleries pressurize and indicate proper (spec) pressure, then you're OK.

Merenth · #8 (**permalink**) 02-15-09, 07:31 PM

Ugh... trying to get the oil pan off but not having any luck. Any way to do it without removing the engine? The transmission is in the way of removing it out the back, combined with the oil pickup, and the frame is in the way in the front. Any ideas?

drmenard · #9 (**permalink**) 02-15-09, 09:40 PM

Whats it in? I always just unbolt the motor mounts and jack it up 6 inches by the crank hub and I can get the pan off... this is a RWD?

cadillac_al · #10 (**permalink**) 02-16-09, 08:41 AM

My memory is kind of foggy but I seem to remember priming an engine once and I couldn't get oil to the rocker arms. I was worried but after priming some more it was fine. I would find a way to get an oil pressure gauge on it somehow; even a temporary one. Then I would take a chance and turn the engine over with the distributer/coil unplugged and see if it builds pressure. If not, it shouldn't hurt anything to turn it for 10 seconds.

534BC · #11 (**permalink**) 02-16-09, 02:13 PM

You mention a "priming tool" , It must have a body to it to plug oil pressure loss. Hopefully it is like an old distributor body and shaft. If it happens to be just a shaft then oil may be leaking out where the distributor goes.

A good indiction is resistance felt on the drill, you should have to hold it with two hands pretty good when pumping. You should feel the resistance very easily.

Merenth · #12 (**permalink**) 02-17-09, 12:54 AM

OK, well, I think the problem may be resolved. The priming tool I have has a small unit on the body that goes around the drive gear on the cam, and a stopper much like the base of the distributor. It's the GM oil pump priming tool from Autozone. Checked the plugs, and they're in place. Checked the O-ring, and it's there. Put everything back together. Attached an oil pressure gauge in place of the sending unit, and yup, sure enough, I'm an idiot it seems. Despite a complete lack of oil up top, it's showing roughly 40 PSI of pressure. I suppose that hopefully with the distributor in place, and once I get it cranking again, that oil decides to make it's way up. Could've avoided all this by doing the gauge first, despite it being a royal pain in the butt since it's on the back of the engine. Regardless, thanks for all your help, and here's hoping all goes well once she turns over.