Oil Press. Problems?
09-05-2006, 11:54 AM
#1
Thread Starter
Join Date: May 2005
Location: Hawaii
Posts: 14
Oil Press. Problems?
Maybe someone can help me with this...I have a 91 5.0 and when I first start her up the oil pressure is fine. Once the cars warms up the oil pressure starts to drop(at idle), but if rpm is increased the oil pressure starts to return to normal. Any one have ideas on what to check first/ what might be causing this? Any help is appreciated thanks,
09-05-2006, 12:03 PM
#2
3rd Gear Member
Join Date: Apr 2006
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Posts: 551
RE: Oil Press. Problems?
What you are describing is normal. A car when its cold will have high oil pressure. When the car warms up the oil pressure will drop some. It will stay low at idle and increase with the rpms. However, what kind of droppage are you seeing. You shouldn't see the oil pressure drop below say 20-25psi even at idle. Do you have some numbers that you can post?
09-05-2006, 12:06 PM
#4
2nd Gear Member
Join Date: May 2005
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Posts: 372
RE: Oil Press. Problems?
its a ford thing there not ment to have high oil pressure. 10lbs per 1000rpms and you should be just fine. i have done alot of research on this subject and everything i have seeen is that you dont need high pressure. when it is cold it will always read higher . when it warms up it will level off. hope this helps
09-05-2006, 01:12 PM
#5
2nd Gear Member
Join Date: Aug 2006
Location:
Posts: 484
RE: Oil Press. Problems?
on my 300k mustang the oil pressure stays normal when its cold and it drops gradually until it's below zero....i think my gauge is broken...i hope idk most of my gauges dont work anyway i havent payd much attention to it. the motor doesnt knock or anything
09-05-2006, 02:44 PM
#9
2nd Gear Member
Join Date: Jun 2006
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Posts: 223
RE: Oil Press. Problems?
On my '89 LX the oil pressure sits around 25-30psi idling after warmed up.
My '88 GT, on the other hand, is at 5psi idling hot! The factory gauge, even though it too shows low, is still in the "NORMAL" range. I thought it was the sending unit so I swapped it out AND installed an autometer gauge. After it's warmed up it drops to 5psi at idle, but goes up to 50 with higher rpms. I swapped out the oil pump with a melling stock replacement, but have the same symptoms. Bearing tolerances are probably a lot looser. Car runs great and I still race it, but I'll either freshen it up or throw my stroker motor in it.
My '88 GT, on the other hand, is at 5psi idling hot! The factory gauge, even though it too shows low, is still in the "NORMAL" range. I thought it was the sending unit so I swapped it out AND installed an autometer gauge. After it's warmed up it drops to 5psi at idle, but goes up to 50 with higher rpms. I swapped out the oil pump with a melling stock replacement, but have the same symptoms. Bearing tolerances are probably a lot looser. Car runs great and I still race it, but I'll either freshen it up or throw my stroker motor in it.
