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Feb 28, 2007 | 06:12 PM

joshn569

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From: MA 413

oil pump

ok heres my deal. 86f250 w460. got hot and shut off on me. did all kinds of trouble shooting, thought it was electrical - wasnt. Turns out that it was the oil pump. The oil pressure dropped below where it should be and as a safety killed the fuel pumps. Now i did notice a slight noise when it was hot, almost like a knock. But when i go out and start the truck cold and when its cold the motor sounds GREAT, no internal noises. Do you think theres any internal damage? If the rods and bearings were not getting enough oil and there were shot they would make noise when cold right?

I plan to put a new oil pump in when the snow melts. What kind of job am i looking at? I really think my motor is o.k. and a new oil pump will make the motor run mint, and an oil pump is way cheaper than a new motor.

Has anyone else had this kind of problem with a 460, or changed the oil pump in there driveway? Is there anywhere i can get a detailed "how to" on changing the oil pump, I am a motorcycle mechanic, and own a 85 ford bronco that im constantly working on so i think i can handle changing the pump.

Feb 28, 2007 | 06:44 PM

big hoss 29

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From: Billings Montana

The only way to tell if you have any internal damage to the engine is to run a compression test on all cylinders. That'll tell you if you have low compression in any of your cylinders. I'm betting everything should be ok, but you never know.

As far as an oil pump goes, yeah, it's quite a job to do. You have to take out the radiator, disconnect the exhaust manifolds,

, then you can replace the pump. I did this to my 86 F-250 2 years ago to replace the rear main seal, and I'm a "might as well do this while I'm here" kind of guy. I figured I'd replace the clutch, timing chain, intake,

at the same time since the motor was out of the truck, and before I knew it, I had the block in the machine shop getting work done to it! It just kinda snow-balled on me. Good luck and let us know how it goes.

One friendly piece of advise:
when you get the new pump in and you're getting ready to put the oil pan back on, use a 1 piece gasket. I didn't and it's been leaking since I fired up the new motor. Not a lot, just enough to let me know that I need to do something about it.

Feb 28, 2007 | 06:54 PM

joshn569

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From: MA 413

why the radiator? Dont i just have to drop the oil pan?

Feb 28, 2007 | 07:06 PM

big hoss 29

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From: Billings Montana

To get to the oil pump, the cross member under the engine doesn't give you the clearance you need unless you raise the engine a bit. Which means you have to disconnect the radiator, fuel lines, wiring, exhaust pipes from the manifolds, disconnect the motor mounts, loosen the trans mount, raise the engine a few inches and put some wood under the mount tabs on the engine block to support it and take off the oil pan. It should just slide out after you unbolt the oil pump from the block and let it drop into the oil pan.

It's probably going to take you the better part of a weekend, a few busted knuckles and lots of pizza and ADULT soda if you have friends help you, but it's worth it when all is said and done.

Feb 28, 2007 | 07:06 PM

Franklin2

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From: Virginia

What oil pressure are you running? You need to check the pressure with a guage before tearing the engine down just to get an idea how bad it is. You can also compare the before reading with the reading after you install the oil pump. The reason I say this is the oil pump may not be the total problem.

A pump has to build pressure "against" something. If you had a brand new pump running wide open spewing oil out in the air, you would have zero pressure. So if your bearings in the engine have a lot of wear, the pump may raise the pressure some because it's new, but you still may have a low oil pressure problem because all the oil is running past the wore out bearings.

Feb 28, 2007 | 07:12 PM

joshn569

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From: MA 413

i had it checked out at a garage, cant remember, but .5 i think is what he said it was. I know its the pump.

Mar 2, 2007 | 03:47 PM

Piffery1

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From: Niceville, FL.

Good luck! But I've never seen an oil pump be the primary (yes, sometimes a contributing) cause of low oil pressure since the advent of high detergent oil. Mostly worn main, rod and/or cam bearings. I'd pull the engine, inspect and mike the crank, and look at the bearings. If their is any copper/brass color showing on the bearing surfaces they need replacing. If the mains are worn a little but not out-of-round you can get 0.001" (maybe 0.002") replacement inserts. The "rule-of-thumb" I've always heard for OHV Ford V-8's is 10 psi per 1000 rpm (i.e., 30 psi @ 3000 rpm) is adequate at normal operating temperature. Get a good mechanical gauge (one that has a copper tubing oil line, at least) and check hot and cold pressures before disassembly.

Last edited by Piffery1; Mar 2, 2007 at 03:50 PM.