81 oil guage

BangkokDean

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On the 81 the oil gauge has been reading 20 lbs for some time so I changed the sending unit and connecting wire and still the gauge reads 20 lbs. I did install a manual gauge on a flexible line and the pressure reads 60+lbs so I guess the gauge is the problem. Now after checking with Corvette Central they tell me the replacement gauge does not need the ceramic resistor in the back that the original has, they say it is now built in the gauge. Does this sound correct?
 
It certainly is possible to do it what way, or more likely calibrate up a gauge that don't need the resistor at all.....

now how/what they did I have NO CLUE....
 
It certainly is possible to do it what way, or more likely calibrate up a gauge that don't need the resistor at all.....

now how/what they did I have NO CLUE....
Well I ordered the gauge so I guess I will find out, the problem is its a PIA to change and then find out it does not work.:shocking:
 
It certainly is possible to do it what way, or more likely calibrate up a gauge that don't need the resistor at all.....

now how/what they did I have NO CLUE....
Well I ordered the gauge so I guess I will find out, the problem is its a PIA to change and then find out it does not work.:shocking:

Pull the wires and jumper the new gauge in with clip leads....

maybe right there at the engine....makes life simple enough...typical one of the posts on the gauge goes to + so jumper to the horn relay....

:shocking:
 
It certainly is possible to do it what way, or more likely calibrate up a gauge that don't need the resistor at all.....

now how/what they did I have NO CLUE....
Well I ordered the gauge so I guess I will find out, the problem is its a PIA to change and then find out it does not work.:shocking:

Pull the wires and jumper the new gauge in with clip leads....

maybe right there at the engine....makes life simple enough...typical one of the posts on the gauge goes to + so jumper to the horn relay....

Good idea I can use the hot wire at the back of the alternator for the +.
 
Dean,

The sending unit and the gauge need to be matched.

Recently on my Buick 350 I rebuilt the oil pump, then connected a hand held gauge to verify oil pressure, then purchased the correct 80 psi sending unit for my application. I was able to verify that the oil pressure and the gauge readings were the same.

Most aftermarket oil pressure sending units do not work with our 'Vette gauges. Try to find an Echlin sending unit, I got mine from NAPA, they range from 40, 60 and 80 psi if I remember correctly. The 80 psi sending unit part number is (Echlin) OP6650. It is a stock GM thread at the base.

My Buick oil pump delivers between 70 and 80 psi at cold start up and then drops to about 20 psi at idle when the oil warms up, all confirmed with the hand held gauge.

On my '79 Vette I did play with some substitute resistors (I have an old gauge set I cannabilized them from) on the back of my oil gauge until I got it in the ball park.
 
Every 81 I have ever been in, the oil prssure gauge bounces at idle.:surrender:
 
Every 81 I have ever been in, the oil prssure gauge bounces at idle.:surrender:

Mine never bounced so I guess I was lucky.The new sending unit came in a AC Delco box that says made in USA, I bought it from Rock auto as that is ware TT suggested I buy it from. I will surly try the gauge before taking the dash apart.
 
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