Oil Pressure Drop
Freshman User
Joined: Nov 2002
Posts: 27
Likes: 0
From: Longmont, CO USA
Oil Pressure Drop
I have a 1975 F250 with the 390 V8. It runs great! It even fires right up after sitting through many cold Colorado days!
I do notice that My Oil pressure appears fine except after I get off of the interstate (usually run around 70mph). When I come to a stop with the transmission in drive, the oil pressure guage drops to the bottom. If I shift into neutral, it immediately rises back to the normal position. This only occurs after I have been driving at high speeds. If I run about 60mph, I don't have the same problem when coming to a stop.
I do have some electrical gremlins that I haven't found the source of, but I don't think these two things are related. Any Ideas??
I do notice that My Oil pressure appears fine except after I get off of the interstate (usually run around 70mph). When I come to a stop with the transmission in drive, the oil pressure guage drops to the bottom. If I shift into neutral, it immediately rises back to the normal position. This only occurs after I have been driving at high speeds. If I run about 60mph, I don't have the same problem when coming to a stop.
I do have some electrical gremlins that I haven't found the source of, but I don't think these two things are related. Any Ideas??
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Oil Pressure Drop
Sounds to me like that engine is a high-miler.
Eventually the oil pressure drops due to wear of the engine bearings.
Nothing lasts forever.
I too would suggest that you attach a real oil pressure gauge to get an exact reading.
Ford's gauges sytem wasn't the best it could be either.
How are the temp & fuel gauges reading ?
Dennis
F.T.E. Assistant Administrator
http://www.clubfte.com/users/mil1ion/SigSanta.JPG
[font color=red]
"May The Spirit Of Christmas Be An Inspiration To You Throughout The Year"[/font]
[link:www.ford-trucks.com/guidelines.html|Club FTE]
[link: motorhaven.autoanything.com|How YOU Can Support This Site]
[link:www.clubfte.com/users/mil1ion/Mil1ion.html|My Website,"North Of The 49th"]
Eventually the oil pressure drops due to wear of the engine bearings.
Nothing lasts forever.
I too would suggest that you attach a real oil pressure gauge to get an exact reading.
Ford's gauges sytem wasn't the best it could be either.
How are the temp & fuel gauges reading ?
Dennis
F.T.E. Assistant Administrator
http://www.clubfte.com/users/mil1ion/SigSanta.JPG
[font color=red]
"May The Spirit Of Christmas Be An Inspiration To You Throughout The Year"[/font]
[link:www.ford-trucks.com/guidelines.html|Club FTE]
[link: motorhaven.autoanything.com|How YOU Can Support This Site]
[link:www.clubfte.com/users/mil1ion/Mil1ion.html|My Website,"North Of The 49th"]
Posting Guru
Joined: Aug 2002
Posts: 1,214
Likes: 2
From: Minneapolis, MN
Oil Pressure Drop
Hey Cory,
Guess what? My '77 with a 400 does exactly the same thing.
High miles and I suspect the oil drainback passages in the heads are slightly clogged. It mainly does it when it's a little low on oil. When I hit the freeway off ramp after running 70 the pressure will drop to nothing, lifters clattering and all. Not every time, just when I'm pushing it hard and the oil is a little low. If I baby it for a little it comes back to normal. Watch your oil level and maybe run it a little above full to see if it still does it. Another possibility would be a leak in the oil pump pickup tube.
Hope this helps.
Greg
'77 F-250 Camper Special 400ci driver
'76 F-250 Supercab 360ci current project
'71 Mach I 429CJ in storage
'79 F-150 for parts
huct on foniks wurkt fer me
Guess what? My '77 with a 400 does exactly the same thing.
High miles and I suspect the oil drainback passages in the heads are slightly clogged. It mainly does it when it's a little low on oil. When I hit the freeway off ramp after running 70 the pressure will drop to nothing, lifters clattering and all. Not every time, just when I'm pushing it hard and the oil is a little low. If I baby it for a little it comes back to normal. Watch your oil level and maybe run it a little above full to see if it still does it. Another possibility would be a leak in the oil pump pickup tube.
Hope this helps.
Greg
'77 F-250 Camper Special 400ci driver
'76 F-250 Supercab 360ci current project
'71 Mach I 429CJ in storage
'79 F-150 for parts
huct on foniks wurkt fer me
