Oil Pressure
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Oil Pressure
When i first start my truck up(1983 F-150 4x4 w/302) when its cold the oil pressure gauge will read that there is good oil pressure, but when the truck warms up and i start to drive down the road the oil gauge will drop all the way down past the lowest point it can go. What could it be? i have valvoline 10w-30 in it should i put heavier oil in it? and what does everyone think about that Lucas Performance Oil. Im thinking about putting some of that in my truck just to protect the motor, because my foot seems to get a little heavy when i climb into the big girl.
Last edited by shotgun1987; Nov 18, 2004 at 12:48 PM.
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Joined: May 2004
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From: Billings Montana
I have the exact same problem with my 86 250 with a 460. When it goes to zero, I listen to the engine to hear for any knocking,luckily, I don't hear anything unusual. If you don't hear anything, it's more than likely the sender. I called Napa and they want $12.00 for one. It looks like an easy change.
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My 85 F-150 Has done that since I bought it in 1995 with 85,000 miles. It now has 141,000 miles. I changed intrument voltage regulator,oil pressure sending switch (Ford Motorcraft pieces) and checked all wiring, still does the same. I checked the pressure with a mechanical gauge and at idle, it kept a steady 48 psi and at 1500 rpm it was a steady 56 psi. Ran for 5 min.,stayed the same. Dont know what it was while driving.
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From: Texas
Low oil pressure when at operating temperature
Assuming your oil pressure gauge is correct....
There are two causes for this condition. Worn main bearings or failing oil pump/pickup. Normally it is main bearings because with worn bearings the tolerance changes when the engine gets up to operating temperature.
Again, assuming that there is nothing wrong with the oil pressure gauge (verified by a known good working gauge connected to the same port) you have a mechanical problem that will cause engine failure.
It only takes > 7 PSI to shut off an oil light (idiot light) and only 10 PSI to read "L" on the pressure gauge. That is disasterous in either situation.
Verify your true oil pressure both cold and warm first.
There are two causes for this condition. Worn main bearings or failing oil pump/pickup. Normally it is main bearings because with worn bearings the tolerance changes when the engine gets up to operating temperature.
Again, assuming that there is nothing wrong with the oil pressure gauge (verified by a known good working gauge connected to the same port) you have a mechanical problem that will cause engine failure.
It only takes > 7 PSI to shut off an oil light (idiot light) and only 10 PSI to read "L" on the pressure gauge. That is disasterous in either situation.
Verify your true oil pressure both cold and warm first.
Last edited by 82F1507.5; Nov 19, 2004 at 09:45 AM.
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Senior User
Joined: Feb 2004
Posts: 204
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From: md
My 86 F250 has just experienced similar problems. My mechanic says the bearings are going and need replacing. He will have to pull the engine. What else should I
1) definitely replace
2) consider replacing
3) check out while the engine is pulled?
Thanks!
Greg
1) definitely replace
2) consider replacing
3) check out while the engine is pulled?
Thanks!
Greg
Logistics Pro
Joined: Jan 2002
Posts: 3,739
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From: GANS
Originally Posted by fornarog
My 86 F250 has just experienced similar problems. My mechanic says the bearings are going and need replacing. He will have to pull the engine. What else should I
1) definitely replace
2) consider replacing
3) check out while the engine is pulled?
1) definitely replace
2) consider replacing
3) check out while the engine is pulled?
Freshman User
Joined: Apr 2004
Posts: 32
Likes: 0
it must be a ford thing i had 89 e-350 with straight six in it and it only ran fine when presure dropped to zero heheand in 460 change is easier then light bulb pull out internal engine cover its located right in the middle of your wiev rhight on top of engine behind intake just grab vise grips and do de job aha use some teflon tape when installing nerw one got tendencies to leak
