Oil pressure issue
Thread Starter
Cruising
Joined: Feb 2007
Posts: 14
Likes: 0
Oil pressure issue
My son's 89 has been displaying low oil pressure when at running temp at a stop. The Oil Pressure cold is between 45-55. When the car is hot(running temp) the OP will read around 5 in Drive at a stop. It cruises around 20-25 OP and will increase to around the mid 30's when we push on it a bit. We have a rebuilt 350ci with a mild cam. We ran a mechanical OP gage along with the stock digital and they are both reading the same. Is this a common thing with these C4's or is it something to be concerned about. We thought maybe a straight weight oil and a High Performance/High volume Oil Pump might solve it. Any thoughts out there?
Burning Brakes
Joined: May 2006
Posts: 857
Likes: 1
From: Morrisonville Illinios
What where your bearing specs after the rebuild? With the same reading on both the elec/mech. gauges it is too low! Did you replace the oil pump? You could pull the pan and check the bearings with some plastic gauge to see where you stand for tolerance. when we put ours back together we had 1-2 thousands on the mains and rods and used a new hig pressure/volume pump. We maintain about 65# when it warms up and over 70 when cold yea it might be high but we are getting oil. using Catrol synthec oil.
Good LUCK
wro87
Good LUCK
wro87
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
Since you already checked the oil pressure with a mechanical gauge and know it is low, you only have a few options. Fix the mechanical issue that is causing the low pressure (pump, excessive bearing clearances, damaged crank, ect..) or try and mask the problem. If the engine is mechanically fine but it has excessive bearing clearances due to previous rebuild being done on the loose side, you could try a high volume pump and it would probably work fine. If the bearings are actually damaged then it is only a matter of time before you will have to remove the engine and repair it.
Corvette Enthusiast
Joined: Oct 2007
Posts: 6,795
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From: So. Cal.
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I have owned SBC's that have had low OP. 5 lbs. at idle. They ran fine like that. They were not my vette either. They were my DD's. Im picky about my vette so I would resolve the issue. I guess it depends how picky you are. Good luck
Corvette Mike
Corvette Mike
