Mechanical oil pressure gauge???

Mark B. White

Registered User
I just purchased a dual pillar pod from autometer for my 94 sc. And of course one of the gauges is going to be a boost gauge but I'm not sure what other gauge i want. I like the air/fuel ratio gauges but if you don't have a adjustable fuel pressure regulator it is kind of pointless. So I thought about a mechanical oil pressure gauge so I can keep a eye on the vital signs of my SC. Can a mechanical oil press. gauge be hooked up on these cars or not because I don't know how accurate the factory gauge is (mine reads really high on oil pressure with 95000 miles). any ideas on gauges or on how to hook up an mechanical oil press guage would be great. I would like to keep the stock gauges working. THANKS
 
Mark,

As has been related many times on the board the stock guage is nothing but an "idiot guage" given the sender is nothing but a switch. Shuts around 7 PSI and opens at like 5 PSI. How far the needle on the Guage deflects is depndant on the current in the circuit which is limited by a 20 Ohm resistor. My suggestion would be to mount an electric oil guage since routing wires is easier than a capilary tube you would need for an mechanical guage. Ground the sensor wire for the stock sender and it will read about normal (ALL the time) but you will not get the Check Guage lite ON all the time either.
 
You could tee the mechanical guage in and leave the factory gauge as is. Run metal capillary tubing or use an isolator... the plastic stuff will leak eventually and you want to lower the possibilty of hot oil spraying around inside your car if you can... That's the main argument for an electrical guage, no oil inside the car.
 
Minor correction to my last. A capillary tube is normally used for a mechanical water & oil temperature guages. There is a fluid in the tube and sender that expands as temps go up and that increased pressure is applied to the guage. A portion of the fluid also flashes to a vapor and adds to the transfer of the pressure to the guage. In a mech. oil pressure guage there is no sealed capillary and you have an open line to the diaphrapm in the guage itself. When you install the engine will try and force oil under pressure into the tube and the air trapped actually goes to the guage since it too is a sealed system. If you do get a leak though you WILL get hot oil into the passenger compartment unless you use an isolator as was mentioned.
 
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