4.2 shows no oil pressure

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Old 02-16-2008, 06:22 PM
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4.2 shows no oil pressure

Hi,

I have a 97 f150 with the 4.2. It has about 50,000 miles on a rebuilt engine. It is a work truck, and the person who was driving it was not changing the oil I recently found out. He calls me and states that the oil pressure was showing 0. I had the truck towed to my garage and after buying a Chilton I have removed the oil pan and cleaned the pickup (completely clogged). I changed the sending unit, and changed oil filters. I hooked everything back up and nothing. So I bought a manual oil pressure gauge, hooked it up at the sending unit and it shows no pressure. Removed the oil filter and no oil comes out when the truck is started. The truck is not rattling yet, it has only been ran about 1 minute since this all started. I am beginning to run out of options. I removed the oil pump and visually inspected it, it looked great, the two big gears rotate very easily. I did notice that when I removed the pump there was no oil dripping when the bolts were removed. What is going on? I hope someone can help. I got two quotes to replace the pump (6 bolts) everyone wants 500 dollars and up. I really cant see paying someone that much money to replace an external pump.
 
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Old 02-16-2008, 08:43 PM
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Is it possible that the pickup tube has a clog somewhere else in the line? Maybe the drive for the oil pump sheard or something?

Besides that, the only other thing I can think of is that is there is air trapped in the pump, so it can't suckup any oil, that sounds unlikely though.
 
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Old 02-17-2008, 08:54 AM
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Why do you need to have someone replace the pump when you have it off already? Just install a new pump,yourself! I think the oil pump being bad is your problem.
 
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Old 02-17-2008, 12:26 PM
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i poured oil through the pickup after i removed it, making sure it will flow. As fare as needing someone to change the pump, I don't need that. I may need to just put it in the shop. What I was getting at was that if they wanted that much money to change the pump, I cant even imagine how much they will want to perform "exploratory surgery" on the truck. Sorry if I was unclear.
 
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Old 02-17-2008, 12:27 PM
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I will replace the pump tomorrow. Hope that is it!
 
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Old 02-17-2008, 02:29 PM
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Thumbs up

Prime it before installation!
 
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Old 02-17-2008, 05:27 PM
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So you do need to prime it?
 
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Old 02-18-2008, 06:40 AM
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hi, i would bet on the oil pump drive shaft being broken as lead head advises to check. even if the pump was worn out it would deliver some pressure.
 
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Old 02-18-2008, 10:42 AM
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just wondering----how do you prime a distributorless engine? Never really tried this one I guess.
 
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Old 02-18-2008, 04:12 PM
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well, i bought a new oil pump today. It came with the pressure relief valve assembly too. I have not removed the timing cover yet, so i just replaced the oil pump. NOTHING. the new pump shows no pressure either. I did notice that the pin that goes into the oil pump gear does not turn by hand, should it? It it stiff and will not rotate. I am back to square one. Anyone want to buy a 97 F150?
 
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Old 02-18-2008, 04:15 PM
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if the drive for the oil pump was not acting properly, how could I tell? It does not seem to be "sheared off" I mean it is sticking down, and I jerked on it, tried to rotate it. I just don't know what to expect from it. If it is not working properly, can I replace it, or is the engine toast?
 
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Old 02-18-2008, 05:16 PM
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Originally Posted by scottie2hottie
just wondering----how do you prime a distributorless engine? Never really tried this one I guess.
Ever bench bleed a master cylinder? Same theory,just use a drill to spin the pump in oil.Sometimes,when I use to build small block Chevys ide fill the pump gears with vasoline! An old racers trick!

Oh,btw Scottie,i'm an ole LSU boy! GEAUX TIGERS!
 
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Old 02-18-2008, 06:01 PM
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Turn the engine with a breaker bar on the vibration dampener bolt, and see if the oil pump turns with it.

Sounds like to me either the oil pump drive is shot, or you just need to prime it.
 
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Old 02-18-2008, 07:52 PM
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Originally Posted by BlueOvalFitter
Ever bench bleed a master cylinder? Same theory,just use a drill to spin the pump in oil.Sometimes,when I use to build small block Chevys ide fill the pump gears with vasoline! An old racers trick!

Oh,btw Scottie,i'm an ole LSU boy! GEAUX TIGERS!
I've used the drill and hex bit trick to prime plenty of times, but never on a motor that doesn't have a distributor. In fact, I've never had a need to prime a motor that didn't have a distributor, YET. I'm sure time will run out for us old fashioned folks. How do you access the pump drive with the pump installed?.....about being LSU boy, guess I can't really trump you, cuz you trumped us pretty bad last month didn't ya LOL.
 
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Old 02-19-2008, 05:59 AM
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thanks leadhead, i will turn the engine. I primed the pump according to the instructions. I sumerged the pump in clean oil and rotated the gears.
 


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