460 engine help....? Oil pressure zero.
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4th Gear
Joined: May 2024
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460 engine help....? Oil pressure zero.
My 1989 motorhome (Ford E350 chassis) with only 40,000 miles on it suddenly lost oil pressure. A mechanical gauge confirmed that it had no oil pressure, and I had the oil pump replaced along with a new filter and new full synthetic oil. The new pump didn't help, still no pressure. My mechanic replaced the oil pickup tube when he replaced the pump. He was aware of the problem with the pickup tubes cracking on that engine. Unfortunately, that was not the problem in my case. With the sending unit removed and the engine running, oil will flow out of the port, but there's no pressure behind it. Same thing happens when the pump driveshaft is spun with an electric drill. Does anybody have any ideas what the problem could be? My mechanic suspects a spun bearing, but I'm hoping it's something simpler. It doesn't make any noise except for sounds like all lifters clattering. At first it sounded like a single lifter was tapping but it soumds like all lifters are clattering now. oil pressure had always been good before this happened, and it has a real analog sending unit, not the idiot switch they put on some Fords. Could a bad bearing cause total loss of oil pressure? If you have any other ideas I would certainly like to hear them.
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Joined: Apr 2004
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Moved here for engine help
Welcome to FTE.
I wouldn't expect excessive bearing wear with so few miles. Not impossible if conditions were right but I doubt you drove through volcanic fallout without an air cleaner. Unless you did....
A single spun bearing wouldn't do it. If all the cam bearings came apart it might do it.
I think you'll have to crack it open to solve this one.
Any oil in the coolant, or coolant in the oil ever?
Welcome to FTE.
I wouldn't expect excessive bearing wear with so few miles. Not impossible if conditions were right but I doubt you drove through volcanic fallout without an air cleaner. Unless you did....
A single spun bearing wouldn't do it. If all the cam bearings came apart it might do it.
I think you'll have to crack it open to solve this one.
Any oil in the coolant, or coolant in the oil ever?
Hotshot
Joined: Jul 2020
Posts: 10,519
Likes: 2,654
From: Near Salt Lake City
What happened to the old pump?
Disassemble the old pump
Maybe something in the pump came apart and is now plugging the port?
Maybe the oil is being pumped into the cooling system through a faulty oil cooler?
Highly unlikely but
Maybe the new oil pump is no good
That oil psi sender is the last port on the oiling system
You might have a blown out rear cam plug, or an oil galley plug?
Disassemble the old pump
Maybe something in the pump came apart and is now plugging the port?
Maybe the oil is being pumped into the cooling system through a faulty oil cooler?
Highly unlikely but
Maybe the new oil pump is no good
That oil psi sender is the last port on the oiling system
You might have a blown out rear cam plug, or an oil galley plug?
Hotshot
Joined: Jul 2020
Posts: 10,519
Likes: 2,654
From: Near Salt Lake City
Sucking air through the pickup or a blown out pump to block gasket should be considered as well
Ford sends gaskets for the pump to block interface with a gasket set but they come as a machined fit with no gasket
Ford sends gaskets for the pump to block interface with a gasket set but they come as a machined fit with no gasket
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