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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Oil Pressure.

  • Thread starter Thread starter JamesB88
  • Start date Start date May 15, 2005
J

JamesB88

Member
May 29, 2004
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16
North Kansas City
May 15, 2005
#1
  • May 15, 2005
  • #1
My dang car is going to make go bankrupt. My problem now is when i reve the car up the oil pressure goes all the way down, at idle it is on the R on the guage, Some times it carrys really good pressure runing about 75 but if i speed up to 80 it goes down the L. Im wondering if it is the pump or the quage, the motor doesnt make any knocking or ticking noises. Im going to put a mechanical guage on it today. But, if that is not it what way would be the best way to get to the oil pump? Pull the motor? Or drop the K-member, but the motor sets on the K member doesnt it? My k member has been notched for headers and i want to replace it along with the struts.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,210
17,894
224
Massachusetts
May 15, 2005
#2
  • May 15, 2005
  • #2
I'd replace the sender first. They have a habit of going.

Oil pumps are a pain to replace. Easiest way i would do it is pull the motor. It allows you to freshen up more than just the oil pump.

It can be done with the motor still in the car, but it involved unbolting and jacking up the motor and securing it. It's still a pain
 

NosPony

New Member
Apr 2, 2004
278
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Canton, Il
May 15, 2005
#3
  • May 15, 2005
  • #3
I had the same problem u decribe on my 87 gt. Replace the sender (easy to do) it fixed my problem.
 

Stang8URMPRT

Active Member
Dec 28, 2003
1,100
1
38
Daytona Beach, FL
May 15, 2005
#4
  • May 15, 2005
  • #4
Oh yeah... Replacing the oil pump with the motor in the car is a pain. Took me about 4 hours on a lift. I would def. say it's the gauge or the sender. It doesn't make sense that it would go DOWN with RPM. Never seen that before. Good luck.
 

Ourobos

Member
Apr 12, 2004
260
1
17
May 15, 2005
#5
  • May 15, 2005
  • #5
Try you mech. gauge first. Then the sender like they suggested. The easiest way for me also is to pull the motor. I had a 90 LX that kept good oil pressure for 15 minutes and a idle. If I went down the road with it warm though, the pressure would drop to zero unless I revved it hard, then it'd go to normal (with a mech. gauge also). Turns out my cam thrust plate had broken a bolt, and the cam wasn't oiling properly. To get that cam out of the block, I had to put a bolt in the cam, attach that to my hoist, and pick the ENTIRE block up for the cam to come out. Hopefully you'll be better off.
 
J

JamesB88

Member
May 29, 2004
228
0
16
North Kansas City
May 15, 2005
#6
  • May 15, 2005
  • #6
Ourobos said:
Try you mech. gauge first. Then the sender like they suggested. The easiest way for me also is to pull the motor. I had a 90 LX that kept good oil pressure for 15 minutes and a idle. If I went down the road with it warm though, the pressure would drop to zero unless I revved it hard, then it'd go to normal (with a mech. gauge also). Turns out my cam thrust plate had broken a bolt, and the cam wasn't oiling properly. To get that cam out of the block, I had to put a bolt in the cam, attach that to my hoist, and pick the ENTIRE block up for the cam to come out. Hopefully you'll be better off.
Click to expand...

Do scare me like that , I think i will try the oil sending unit first, the damn car has so many leaks in the junky headers i cant hear if the motor is ticking or not. Its ok when im going along around 70 but if i speed up any it drops. Im going to try to get a mechanical guage hooked up tommarow, where do i hook it up at? Screw it into the block some where but where?

My dad said that his old truck did the same thing my car is doing then it just quit working all together, I thought it was weird for it to go down when i rev it up but i quess the pump could be really worn out. Whats bad about it all is the guy i bought it from said the motor only had about 10k miles on it, how would the pump go bad in 10. Ive been putting 5 and a 1/4 quarts of oil in it and it reads way over the full line but thats what my manual says hopefully i didnt screw anything up. My freinds dad told me my main bearings could be going bad but i dont see how that relates to the oil pressure. Ill have to go tommarow and get a sending unit, Im pretty sure i got a mechanical guage around here some where. Thanks James.
 
D

Dohc32vMarkVIII

New Member
Mar 31, 2005
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0
May 15, 2005
#7
  • May 15, 2005
  • #7
What should the fuel pressure be on a stock 5.0? I have a guage hooked up and I just want to make sure it's within normal specs.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
May 15, 2005
#8
  • May 15, 2005
  • #8
Dohc32vMarkVIII said:
What should the fuel pressure be on a stock 5.0? I have a guage hooked up and I just want to make sure it's within normal specs.
Click to expand...
do you want fuel pressure or oil pressure? fuel is ~39 with the vac line off and capped. with the line attached (as the car is when you drive it), it is generally ~32 PSI (depends upon cam selection, etc).

OP is across the board. 25+ at warm idle is alright. it really depends upon conditions, viscosity, etc.

good luck.
 
J

JamesB88

Member
May 29, 2004
228
0
16
North Kansas City
May 16, 2005
#9
  • May 16, 2005
  • #9
I chanced the sending unit today and now its on the A at idle but instead of going down when i rev it up it goes up. Now i can finally get on my car without the oil pressure going to zero, glad that was all that was wrong with it. Thanks for the tips you guys.. James.
 
F

fiveohGT

New Member
Jun 22, 2004
353
1
0
Fairfax Virginia
May 16, 2005
#10
  • May 16, 2005
  • #10
JamesB88 said:
the damn car has so many leaks in the junky headers i cant hear if the motor is ticking or not.
Click to expand...

Once I replaced my oil pump, regasketed my rear main seal, valve covers, and oil pan, and regasketed my headers and used arp bolt my car was like new!
 
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