Oil pressure drop at idle, only in drive and when warm????


Mattl12

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1990 Ford Ranger 2.9 V6
73000 miles
Heads and head gaskets recently changed, cooling/radiator system almost entirely new as well.
Changed the Oil pressure switch already. Changed oil and filter yesterday, high mileage synthetic blend 10W-30. Drop off only happens when warm and in drive, hitting the gas makes pressure go backup. No change in sound/noise. Just got first hiccup/vibration today.


Haven't guaged the oil pressure yet. OBD connection is clogged as it was opened the first time today, needs to be cleaned so I have no codes.


Thoughts????
 


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Sounds like it is time for an HV oil pump.
 

Mattl12

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Isn't replacing an oil pump on a 2.9 ranger a major job???
 

Mattl12

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Would you drive it or is this a park it and tow ordeal?
 

alwaysFlOoReD

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I would put a real gauge on there and see what it says.
 

Paulos

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Mine has 300K+, runs at 40psi on the highway and sometimes 15-20psi at idle. Surprisingly, I have no ticking noise. I just don't stay still long enough for it to sit and idle much when it's warm :). Mine needs a rebuild. And cam bearings.
 

Mattl12

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I would put a real gauge on there and see what it says.
Don't own a gauge and don't know what to look for/read it if I did. Gauge plugs in right where the pressure switch I just replaced screws in right? What I'm finding is the switch says there is pressure over 5 or 0 pressure (Dashboard "Gauge") and nothing else. Unless the repair costs are significant enough to junk the truck I will put on an after market "True Gauge".
 

Mattl12

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Mine has 300K+, runs at 40psi on the highway and sometimes 15-20psi at idle. Surprisingly, I have no ticking noise. I just don't stay still long enough for it to sit and idle much when it's warm :). Mine needs a rebuild. And cam bearings.

Getting on the gas seems to keep oil pressure level enough, like I said only at idle and in drive. Check engine light is coming on and off intermittently and that freaks me out.
 

Mattl12

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Oh yeah does an "Electrical Brown Out" mean anything to any of you as far as oil pressure readings? When I found a discussion that matches my problem almost exactly that came up, unfortunately there was not more to that?
 

Uncle Gump

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Yes a mechanical gauge will screw in where the switch is located. Get a gauge in there and see what the readings are.

Paulos... 15 to 20 psi on a hot idle sounds pretty good to me actually...
 


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