Oil pressure question.
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TECH Resident
Joined: Feb 2006
Posts: 855
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From: Omahaish. Nebraska.
Oil pressure question. Ok, at cold idle, everything is normal, and at cruising when SUPER hot (like 210*) the pressure holds at about 40, give or take a few psi depending on engine speed, but the pressure drops down to about 25 psi. The car is an auto, so I know it'll be a bit lower than you m6 guys, but does that sound normal, wicked heat soak or is something wrong?? I've seen other autos do the same thing, so I'm curious for a couple of people. I think it's heat soak, cause once the engine cools a little with highway driving, the pressure goes back up to about 30 at idle, and the temps here have been 90+ for a week at least.
Pressure sounds fine just remember the pump will show a higher pressure when cold thats when the oil is thickest, and shows more restriction going through the pump thus showing a higher oil pressure. Once warm the flow does not change just the amount of pressure it takes to move it. Now if you go from 40 psi to 5psi once its warm up then u have a problem. I think gm says for every 100 rpm oil should rise 10 psi dont quote me on that tho.
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
Yea the guys with the real healthy OP on here **** me off.LOL Mine idles just under 40 when it gets real hot but at 60MPH is only 42-43 on a 77k motor. It will aproach 60 at 6k like yours. On the other hand my 5.3 179 k motor in my truck idles 43-44 and runs 54-55 hot but won't go higher at WOT
WEIRD. Don't lose any sleep over it
An external oil cooler may help. I am considering one.
WEIRD. Don't lose any sleep over it An external oil cooler may help. I am considering one. 
