Oil pump wont prime with zero oil pressure after engine rebuild

CandyRed 88

Member
Dec 23, 2020
9
1
13
30
Florida
I'm in need of help ASAP.

I rebuilt my 302, did some bolt ons, including a CAM E303. I followed everything installation wise to an absolute T. Minus priming my oil pump. I put a high volume one from Mulling on it. Rookie mistake I know. But it is my first rebuild. I get 1 mistake right?

Okay so I primed the oil pump for over 40 mins CCW (knew i was screwed because 5-10mins is the norm for oil to come up) and got no oil coming from the rods or rockers. Removed all applicable parts and did the whole starter "trick" and still no luck. I even did the starter and drill trick.

What do I do? Pull the pan and replace the brand new pump? Check somewhere for something? I did my timing gear and chain settup the way it was calling for it to be installed. I cleaned all passage of where oil would travel.

Oh and BTW I found out I had no oil going to the rockers because I had a knock. Car ran dry for 10 mins . SOMEONE PLEASE HELP ME
 
  • Sponsors(?)


General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
19,470
6,489
193
polk county florida
Did you pack the pump gears with grease or vasaline?
Did you set the pickup tube about 3/8 off the floor of the oil pan?
Install the gasket for the pickup tube to pump.
 

CandyRed 88

Member
Dec 23, 2020
9
1
13
30
Florida
Did you pack the pump gears with grease or vasaline?
Did you set the pickup tube about 3/8 off the floor of the oil pan?
Install the gasket for the pickup tube to pump.
I did not. I dont recall verifying clearances with the new pump. I installed all gaskets.
I just heard of 3 block off plates, little silver things and I can't find them anywhere. I have a picture of what they are. I didnt install them.
 

Attachments

  • Screenshot_20201223-190731_YouTube.jpg
    Screenshot_20201223-190731_YouTube.jpg
    442.6 KB · Views: 59

jozsefsz

Mustang Master
Aug 11, 2013
1,192
296
114
50
Cleveland OH Area
About the silver things - did you remove the existing pressed-in oil galley plugs to clean the passages? If you didn't, and it's your block (no one else messed with it) then the original plugs would still be there. It's not likely that. If you removed them and forgot to install replacements, it could be causing a big problem.

The oiling system isn't all that complicated - if the pump is turning, the pickup isn't damaged, and you don't have any major air-leaks between the pickup and pump or between the pump and block, it should be moving oil. And CCW at the distributor does the turning.

It sounds to me that your pump is just sucking air. Without some oil in there, or vaseline / grease as mentioned above, it can't effectively pump the oil up-hill through the pickup and over to the filter.

Here's something relatively painless you could try - without having to pull the engine to get at the pump again.

First thing is remove your filter. I assume you installed a new one, and probably didn't fill it with oil (since that's messy on a horizontally-mounted filter). If there's oil in the filter, then the pump is working and getting the oil up to it. Your problem is higher up in the block, perhaps the galley plugs or something else. If you filled the filter with oil, then ignore this step as it won't tell you much.

Get a syringe or one of those fluid-pumps from Autozone or the like. Remove your oil filter, and try and pump a bunch of oil into the port opening where the filter had mounted. Not into the big center threaded part (that's where the oil exits the filter into the block) but into the smaller hole on the perimeter (near the bottom if I recall). The oil you introduce should find its way down into the oil pump gears and prime it from up top. Fill the filter with oil, reinstall, and try your priming again. Hopefully you'll have better luck.

If you still don't have luck, leave the filter off and try priming again. If you make a royal mess (the pump is getting oil into the filter) then your problem is higher up (like the galley plugs you mention). If putting oil in through the filter opening doesn't work, you could try removing the oil pressure sending unit and injecting some oil there. Another option would be to severely overfill the sump (10 quarts or whatever) to the point where the oil is above the level of the pump body, and to try and prime again. The hydraulic pressure that would create would allow the pump to prime itself once it evacuates the air in the pickup tube. Edit: drain out the excess before you run the engine or you'll damage stuff.

Full disclosure, I've never tried any of these ideas (I always top-fill the pump with oil and make sure it works before I install it). I'm just hoping it'll work for you (it theoretically should) or minimally help pinpoint where your problem is. Best of luck!
 
  • Like
  • Useful
Reactions: 1 users

rockyracoon

10 Year Member
Nov 23, 2005
819
23
39
margate NJ
Go to harbor freight and buy a garden sprayer. Remove the oil psi sender and pump the oil through there. Those sprayer can build up a decent amount of pressure which is a good thing . Iirc I bought a hose barb and connected the sprayer that way.
 
  • Like
Reactions: 1 user

96pushrod

I think they're a little easier to get off
May 15, 2018
961
584
103
29
Savannah
If the engine ran completely dry for 10 mins you’ll have other problems.

If you have zero oil getting up to the top end, it’s almost 100% certainty that there is one or more galley plugs missing. It’s Really the only thing that will make no oil come up. Even the gasket on the pump isn’t 100% necessary as those surfaces are usually very flat, not enough to not let any oil pass.

Not having the gears packed with grease won’t make any difference either. Whether they’re slap full of grease or bone dry, it’ll suck oil when primed with a drill.

Look up a diagram of the entire oil system and you’ll see exactly where to check for the plugs.
 
  • Like
Reactions: 1 users

revhead347

Apparently my ex-husband made that mistake.
15 Year Member
Jun 14, 2004
8,752
1,433
214
41
Acworth, GA
As mentioned, you don't put grease in the gears of a Ford oil pump. That's for engines that can't be primed with a tool.

Kurt
 

marcelo

Active Member
Feb 25, 2018
208
46
38
60
Quepos, Costa Rica, Central America
you run the engine for 10 min knowing there is no oil pressure ?????... good one .... its time to start again .. and by the way ..melling HV pump ..why is that a Rookie mistake ???? I run HV and HP pumps from Melling and no Problems ... if all good you can turn the oil pump Shaft by hand or with a hand tool and get Oil pressure in a Minute or less ... this pumps are making a vacuum turning them by hand and sucking oil .. and with a drill you should get oil pressure in seconds...if not ..there is something wrong ...:notnice::notnice: Youtube is full of Videos..how to do it right ... 1. take the Distributor out and check the oil pump drive Shaft sitting correct in the Hole and pump...
 

Attachments

  • 91550100_L_ff5bf13f-e2af-4dfc-b387-b05399ab0971.jpg
    91550100_L_ff5bf13f-e2af-4dfc-b387-b05399ab0971.jpg
    8 KB · Views: 37
  • Disthole.jpg
    Disthole.jpg
    21.1 KB · Views: 42
Last edited:

stanger90

New Member
Jan 11, 2007
8
0
1
Pull the oil pressure sensor and run the pump again. Should definitely have oil there, I think it's right above the pump. My guess would be the oil gallery plug in the back of the valley came out. Mine blew out after a first start on a new rebuild once.
 

CandyRed 88

Member
Dec 23, 2020
9
1
13
30
Florida
About the silver things - did you remove the existing pressed-in oil galley plugs to clean the passages? If you didn't, and it's your block (no one else messed with it) then the original plugs would still be there. It's not likely that. If you removed them and forgot to install replacements, it could be causing a big problem.

The oiling system isn't all that complicated - if the pump is turning, the pickup isn't damaged, and you don't have any major air-leaks between the pickup and pump or between the pump and block, it should be moving oil. And CCW at the distributor does the turning.

It sounds to me that your pump is just sucking air. Without some oil in there, or vaseline / grease as mentioned above, it can't effectively pump the oil up-hill through the pickup and over to the filter.

Here's something relatively painless you could try - without having to pull the engine to get at the pump again.

First thing is remove your filter. I assume you installed a new one, and probably didn't fill it with oil (since that's messy on a horizontally-mounted filter). If there's oil in the filter, then the pump is working and getting the oil up to it. Your problem is higher up in the block, perhaps the galley plugs or something else. If you filled the filter with oil, then ignore this step as it won't tell you much.

Get a syringe or one of those fluid-pumps from Autozone or the like. Remove your oil filter, and try and pump a bunch of oil into the port opening where the filter had mounted. Not into the big center threaded part (that's where the oil exits the filter into the block) but into the smaller hole on the perimeter (near the bottom if I recall). The oil you introduce should find its way down into the oil pump gears and prime it from up top. Fill the filter with oil, reinstall, and try your priming again. Hopefully you'll have better luck.

If you still don't have luck, leave the filter off and try priming again. If you make a royal mess (the pump is getting oil into the filter) then your problem is higher up (like the galley plugs you mention). If putting oil in through the filter opening doesn't work, you could try removing the oil pressure sending unit and injecting some oil there. Another option would be to severely overfill the sump (10 quarts or whatever) to the point where the oil is above the level of the pump body, and to try and prime again. The hydraulic pressure that would create would allow the pump to prime itself once it evacuates the air in the pickup tube. Edit: drain out the excess before you run the engine or you'll damage stuff.

Full disclosure, I've never tried any of these ideas (I always top-fill the pump with oil and make sure it works before I install it). I'm just hoping it'll work for you (it theoretically should) or minimally help pinpoint where your problem is. Best of luck!
Thats a damn great idea. I appreciate the help. I definitely didn't taken any freezer plugs out or remember them being there. I'm the 10th owner on the mustang so I have no idea. I've heard of clearance issues with a better oil pump so I may need to add a quart more every time now.
 

nickyb

WAIT,you now have a pair?
10 Year Member
Apr 3, 2009
968
426
93
58
nevada
I've never heard of a better oil pump needing an extra quart of oil , you need help , possibly medication.Now a deeper oil pan, well I believe that's too deep for you.
 
  • Dislike
Reactions: 1 user

96pushrod

I think they're a little easier to get off
May 15, 2018
961
584
103
29
Savannah
I've never heard of a better oil pump needing an extra quart of oil , you need help , possibly medication.Now a deeper oil pan, well I believe that's too deep for you.
Yeah, I doubt that’s be problem.
Oil would circulate if you only had 3 quarts in there while priming.
 

nickyb

WAIT,you now have a pair?
10 Year Member
Apr 3, 2009
968
426
93
58
nevada
On a serious note now, you will have to check that all your oil valley plugs are installed( take off timming cover and look behind the cam sproket) take pics and post em. I hope there isn't any damage and you figure this out soon.If I was closer I'd help you out.
 

CandyRed 88

Member
Dec 23, 2020
9
1
13
30
Florida
On a serious note now, you will have to check that all your oil valley plugs are installed( take off timming cover and look behind the cam sproket) take pics and post em. I hope there isn't any damage and you figure this out soon.If I was closer I'd help you out.
 

Attachments

  • Screenshot_20201223-174911_Gallery.jpg
    Screenshot_20201223-174911_Gallery.jpg
    569.4 KB · Views: 39

CandyRed 88

Member
Dec 23, 2020
9
1
13
30
Florida
And thank you for the serious reply. I was about to jump the ship here with people like that. Doesn't look like plugs were there. Thats after the CAM install. I found the problem though. Oil pump shaft popped out.