No Oil Pressure after Rebuild? HELP!
 

So me and my dad recently rebuild the 4.6 DOHC out of a Mach 1. Putting new everything including a Ford Performace high flow oil pump. We primed the system with the big sprayer pump method. Pumped almost 5 quarts and then topped it off thru the valve covers. Upon start up there was virtually no oil pressure for a good 5 seconds so we quickly shut it off and suspected a bad oil sending unit. As we were putting a new one on we realized that before the rebuild the oil pressure showed fine on the gauge so why would the unit go bad within the time of the rebuild, so instead went out to get a manual gauge and hooked it up to where the electric unit screws into. The needle did not budge. Getting desperate we finally undid unit and left the hole open and cranked the engine over with a non programmed key so it would just crank and not fire up, just seeing any signs the oil pump was working and hoping oil would squirt out of the hole. Not even a drop came out. At this point I don't know what to do or suspect. I'm guessing the oil pump if defective but it just seems like a really slim chance a brand new ford pump would not work like that. The pickup tube also had clearance as the oil pan went on smoothly without any force having to be applied. Getting ready to pull the **** front cover off and see if I can see anything that went wrong with the pump. Has anyone ever experienced this? I would love an answer or insite of what could be the source of my problem, if not the pump. Thanks guys

Unfortunately you've already done the easy stuff. The only thing left is to start pulling covers off. Hopefully it's something simple.

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Re: No Oil Pressure after Rebuild? HELP!
 

Ya, I went over it before I posted, and could've sworn I didn't have a lot of those errors in there.

Re: No Oil Pressure after Rebuild? HELP!
 

Interesting. Let us know what you find.

Re: No Oil Pressure after Rebuild? HELP!
 

Took the front cover off a while ago, looks kinda dry on the chains so we're still suspecting the brand new pump. We'll find out forsure I guess until we put another pump and time it all over again. Any way of actually testing the oil pump to see if its actually bad?

Did you remember the o-ring for the pickup? I'd do the clay trick for checking the pickup to pan clearance. No force doesn't mean it's not too close. Short of missing the gears the only other thing I can think of is the pressure spring being bad.

Although I have an old timer story. I did a cam swap in the 351W in my 70. During the break in the cam went flat and took out my 2500 mile engine. While pulling things apart I found the journals were dry. I figured my pump died. Until I pulled the oil filter and turned it over. A quart of oil came running out. I looked down the filter and could see where the media had come apart and moved blocking the holes. Oil was going in, but not coming out. I haven't run a Fram filter since.

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Re: No Oil Pressure after Rebuild? HELP!
 

Yes, o-ring was placed on tube. What's the clay trick and are you talking about the Pressure spring on the oil pump?
****, now you're having me worrying about my oil filter doing a freak thing like that. I only pulled the sending unit out and cranked to see if oil was coming out but in order for oil to get to the sending unit it would have to pass thru the filter first. I should've also pulled the filter to make certain. It is a new filter but it's like the cheapest one since I was planning to change the oil within 500 miles anyway. It wasn't a Fram I know that lol. Hope I didn't tear everything back apart because of an oil filter. I'll have to pull it off and make sure it's not split like yours was. Thanks for the story!

Re: No Oil Pressure after Rebuild? HELP!
 

Im at a loss here, I mean the pump is turned by the crank so unless its completely bypassing I have a hard time seeing how it would be the pump.

if you're on facebook go join the NA SVT Cams/Intakes tech group and post up whats going on, EXTREMELY knowledgeable guys

Re: No Oil Pressure after Rebuild? HELP!
 

I'm in the same boat. I have a real hard time believing it is the pump but it is always possible to receive defective parts. At this point I just don't know what else it could be. I will definitely look into the fb page.

The clay trick is you place a piece of clay on the pickup then place the pan on the engine. Remove the pan and measure how thick the clay is. That's your pick-up to pan clearance. I've used Silly Putty too. I don't know if that stuff is still around.

Yeah, I'm referring to the bypass spring in the pump. I think I'd pull the filter and adapter at this point. See if there's any signs of oil in the main galley right there.

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