high oil pressure
Freshman User
Joined: Mar 2008
Posts: 48
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From: Mentone Alabama
milky color on oil cap
Yall might get a laugh out of this. other than my f150 i recently bought my only other ford id ever owned was a 86 4wd bronco with the 300c.i. it leaked a lot of oil and id just bought it, the motor was a 76 from a 2wd and the dipstick was not there it was broke off and just used as a cap.i guess because the pans were diff from 2wd-4wd, so every time i was fillin up id just put a little oil in it.well one particularly warm day i pulled the fill cap and bam milky oil. i thought id blown a head gasket so i rip the head off and of course every thing was fine it was just a little condensation, there was a little milky buildup all along the top of the valve cover but particularly there on the bottom of my fill cap.
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
How is the exaust flow going out the tailpipe?
Check the oil pressure with a manual guage.
Too much engine backpressure from a plugged exaust, or sticky exaust valves, can cause excessive blowby, and blistered white or yellow spark plugs. should cause a definate loss of power though.
Excessive oil pressure from a stuck oil pressure relief valve on the oil pump can cause excessive oil to pass the rings and valve guide seals, puke it out the top of the engine etc. This should cause the plugs to foul with oil deposits however.
Plugged up passages in the block. etc...
Confirm your oil pressure though. The engine being out of a different vehicle, the sending unit and the gauge my not match, causing a false reading.
I will say usually, worn rings, or valve guides, will cause a drop in oil pressure, not an increase.
Check the oil pressure with a manual guage.
Too much engine backpressure from a plugged exaust, or sticky exaust valves, can cause excessive blowby, and blistered white or yellow spark plugs. should cause a definate loss of power though.
Excessive oil pressure from a stuck oil pressure relief valve on the oil pump can cause excessive oil to pass the rings and valve guide seals, puke it out the top of the engine etc. This should cause the plugs to foul with oil deposits however.
Plugged up passages in the block. etc...
Confirm your oil pressure though. The engine being out of a different vehicle, the sending unit and the gauge my not match, causing a false reading.
I will say usually, worn rings, or valve guides, will cause a drop in oil pressure, not an increase.
Moderator
Joined: Jan 2001
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From: Virginia
Excessive oil pressure from a stuck oil pressure relief valve on the oil pump can cause excessive oil to pass the rings and valve guide seals, puke it out the top of the engine etc.
Had a look at the compression finally. All 8 cylinders were between 110-120psi. The other thing we checked was vacuum. Using the PCV port on the back of the carb, there was 13"Hg at idle.
2 quarts every 3000 miles is another indicator. This engine has wear. You can keep driving it, and it probably will give you some more years of service, or if you are worried about it and are going to fix the truck up, I would get a new engine or have this one rebuilt.
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
I will admit it is very unlikely.
A worn engine usually means low oil pressure, not extremely high though.
Really need a mechanical oil pressure reading. It may not be as high as the OP thinks it is.
A worn engine usually means low oil pressure, not extremely high though.
Really need a mechanical oil pressure reading. It may not be as high as the OP thinks it is.
Posting Guru
Joined: Jun 2004
Posts: 1,635
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From: Niceville, FL.
Compression tests should be run with engine at normal operating temperature, all sparkplugs removed and choke & throttle wide open. Record the readings then put about a teaspoon of oil in each cylinder and redo tests. If worn rings are the problem then the compression readings should increase after the oil is put in. Install a mechanical oil pressure gauge. A good engine should produce 40 to 60 psi at normal operating temperature. A "rule of thumb" for acceptable oil pressure is 10 psi per 1000 rpm (for example: 20 psi @ 2000 rpm).
Junior User
Joined: Nov 2007
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Should I look into this engine? Would it maybe be out of a car or a truck? What would you offer for it?
Ford 400 with tranny - Peterborough Car Parts For Sale - Kijiji Peterborough
Ford 400 with tranny - Peterborough Car Parts For Sale - Kijiji Peterborough
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Moderator
Joined: Jan 2001
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From: Virginia
A 400 is a different engine family. It will not be a direct fit, though you could make it fit, in my opinion it would be a waste of time and money to do so. Looking at it, I am not sure it is a 400, and there never was a 400 made with a 4speed automatic tranny. So who knows what it really is.
Junior User
Joined: Nov 2007
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Ah, right on. I just was looking at one of the local ads websites, was looking for wheels/tires and any Ford parts, that came up. I don't need anymore headaches.
Ok, so I see a few comments that I should check the oil pressure with a mechanical gauge because the interior dash gauge might just be reading artificially high, but how does that help explain why the engine is spitting oil out everywhere it can around the heads? Should I be pulling the heads off the engine to see what's going on inside?
Ok, so I see a few comments that I should check the oil pressure with a mechanical gauge because the interior dash gauge might just be reading artificially high, but how does that help explain why the engine is spitting oil out everywhere it can around the heads? Should I be pulling the heads off the engine to see what's going on inside?
Moderator
Joined: Jan 2001
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From: Virginia
I personally would not go into your engine, without being prepared to find you need to rebuild it. In other words when you pull the heads off, you will probably find ridges on top of the cylinders. This will verify the engine needs rebuilding, but then what are you going to do? If you do not need the truck everything is fine and you can go ahead and get it rebuilt. If you need the truck, now it's torn down and you can't use it. I would just keep it running while saving up for another engine to rebuild or a good used engine to swap in.
I am not there, but from what you have described, I just think it's wore out.
I am not there, but from what you have described, I just think it's wore out.
Junior User
Joined: Nov 2007
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I drive the truck everyday, so I think I'll go with your suggestion, as it really makes a lot of sense to me. I'll start looking for an engine locally and rebuild it to drop in the truck and just keep driving on this one for now. Sure it pukes oil and makes a mess, but it starts every morning and runs all day long.
EDIT: Consider my question fully answered. The high oil pressure problem has been resolved. Thanks for all your input!
EDIT: Consider my question fully answered. The high oil pressure problem has been resolved. Thanks for all your input!
New User
Joined: Aug 2006
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I see in one of your pictures the breather line from your filler cap looks like it is capped off(plugged),if it is unplug it.On a tired motor if you plug that it will do exactly what your motor is doing even with a working PCV.Give it a try.
Post Fiend
Joined: Jul 2004
Posts: 8,786
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From: Northern California
A: Too much oil in crankcase.
B: Blown head gasket pressurising the oil passages.
among other things etc...
But if you have low oil pressure, then I could recomend you buy a thicker oil than 5w/30. Like 20w/50, and a bottle of no smoke or other addtive to help aleviate some of the symptoms until you tear the engine down and/or rebuild your engine.
Without knowing the true oil pressure, I don't want to recomend a thicker oil and make it worse.
EDIT: Seems you solved the high oil pressure, what was it may I ask?
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