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Engine knocking?


juntjoo

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What do you think? Is it shot? One mechanic said it sounded like the rod bearing. It got worse.
Maybe it's obvious and there's nothing else that could be hitting the moving parts and I'll just ask about how much to drop a used one in if I don't just shop around for another.
 


rusty ol ranger

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What do you think? Is it shot? One mechanic said it sounded like the rod bearing. It got worse.
Maybe it's obvious and there's nothing else that could be hitting the moving parts and I'll just ask about how much to drop a used one in if I don't just shop around for another.
More then likely a rod. Rods are usually noisest when the revs are coming down.
 

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idk if your oil pressure gauge is accurate but it wasnt registering and its knocking on heavens door. Id say rod bearing for sure.
 

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What does the oil pressure gauge have to do with it?
 

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What does the oil pressure gauge have to do with it?
Well, it gauges the oil pressure, or a lack thereof.

Low oil pressure is generally bad for an engine. It can cause them to make unusual noises.
 

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What does the oil pressure gauge have to do with it?
Well no oil pressure allows metal on metal contact because there’s no pressure to retain the oil barrier. The old ford pressure senders kinda suck so they aren’t always accurate. In my truck the gauge always shows low but I never once heard a lifter tick.
 

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What does the oil pressure gauge have to do with it?
Low oil pressure results in a knocking engine.

Pull your dipatick....i bet the oil looks like glitter
 

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The mechanic said something about the oil, from under the hood. He didn't see my gauges. Not sure exactly what he said. No leaks. I'm not at my truck at the moment but I wasn't noticing anything about the pressure gauge either because it doesn't work or I just never thought to pay attention to it. Or I thought it was oil level. But one or two gauges don't work and I've been content just knowing how fast I'm going and what temp the engine is. So if the low pressure prevented the rod bearing... Isn't it low enough down there to get oil? How does the bearing get oil? Dropped from above somewhere? And how does the engine lose oil pressure? Thanks
 

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The mechanic said something about the oil, from under the hood. He didn't see my gauges. Not sure exactly what he said. No leaks. I'm not at my truck at the moment but I wasn't noticing anything about the pressure gauge either because it doesn't work or I just never thought to pay attention to it. Or I thought it was oil level. But one or two gauges don't work and I've been content just knowing how fast I'm going and what temp the engine is. So if the low pressure prevented the rod bearing... Isn't it low enough down there to get oil? How does the bearing get oil? Dropped from above somewhere? And how does the engine lose oil pressure? Thanks



Pretty simplified but will give you the idea.

Engines lose oil pressure when a) they are worn out and the tolerences between bearinga get so fat the oil can no longer provide protection, b) the pump gets weak from mileage or C) the galleys get plugged from lack of maintence.

As loud as yours is you might as well get it rebuilt or get a crate/junkyard motor installed
 

juntjoo

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So how did I lose oil pressure? What's the usual culprit? The oil pump? Oh, I have been having the "check engine" light go on intermittently, around shifting gears, 1 and 2 I believe. Perhaps I should have paid more attention. So many lights and gauges not happy I lost track and thought I'd look into it on my next oil change coming up. I had been doing full synthetic every 5k. Was that not frequent enough? That would cause dirty oil though, not low pressure
 

juntjoo

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New (used) engine <1k, rebuilt 2k. Plus labor 2.5g's at least. IDK. What would you do? I bought if 20k miles ago for 4k.
 

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If you rebuild the engine, you essentially have a new engine.

if you buy a used one, it is already going to have 100k or so miles, and you inherited any issues that engine was having before they sold the truck for scrap.

A used engine will get you moving, I have installed used engines in cars in the past to get them back on the road.

a rebuild would be better if you have the cash and time to wait. Especially if you plan on keeping the truck for a while.
 

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How does the bearing get oil?
I just happen to have some show&tell items handy.

Here is a crank shaft. I am pointing to a hole on one of the surfaces where a bearing rides. This surface is called a journal. At one end of the crank shaft, there is another hole that lines up with a place where pressurized oil is supplied to it. That oil then comes out of these holes on the journals to supply a film of oil to prevent the bearing surface from actually touching the journal surface. There must be a certain amount of pressure to keep the film of oil thick enough for this purpose.

20201126_110817.jpg


In this picture, I laid a piston rod near the crank journal. Inside the big hole on the end of the rod, a thin piece of metal, probably brass or bronze rides between the rod and the crank journal. That is the bearing that wears out due to lack of lubrication or dirty lubricant. Also, the oil eventually breaks down chemically and can't preform properly. That is why periodic oil changes are necessary.

20201126_110911.jpg
 

juntjoo

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If you rebuild the engine, you essentially have a new engine.

if you buy a used one, it is already going to have 100k or so miles, and you inherited any issues that engine was having before they sold the truck for scrap.

A used engine will get you moving, I have installed used engines in cars in the past to get them back on the road.

a rebuild would be better if you have the cash and time to wait. Especially if you plan on keeping the truck for a while.
Hmm... So what's cheapest? And(preferably) best(quality)? Sounds like a rebuild would be best if spending enough to buy a new used truck. Can you rebuild it intact from underneath? If so sounds like all in all it would be the best way to go. No shipping, no engine removal, no extra parts.
 

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Most car and small truck engine rebuilds are done outside the vehicle. It's much easier and faster.
 

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