[Guest]

67 289 C with concern about oil pressure. Gauge in dash shows very low and only coming into normal range above idle. Have not had it long enough to vouch for the accuracy of gauges. Can also hear at least one lifter tapping. How do I test the oil pressure accurately? Want to make sure I'm not about to seize it.

 

[Axnjxn]

To test it accurately you need to hook up a real gauge, one with numbers. If you just want to check the accuracy of the gauge set you have, just buy a $20 el cheapo, hook it up, and compare, then unhook it. Personally, I would install at least an aftermarket oil pressure and water temp gauge.

The rule of thumb for oil pressure is 10 psi of pressure for every 1,000 rpm of engine speed. I get about 35 psi at idle, and up to 60 on the freeway.

A ticking lifter can be a symptom of not enough oil pressure. There can be numerous causes of this, but my first question would be, how much carbon deposit is in your engine? have you popped off a valve cover? How long does it take for your oil to turn black?

 

[Guest]

I'm going to pull off a valve cover tonight but I'm afraid the engine has been neglected for a long time. Now that we have her we are trying to set things right but the list is very long. For now, I'd like to use the vacumn/pressure gauge I have just to see where I am, then add some aftermarket gauges later. Where/how do I hook up to read the oil pressure?

 

[Axnjxn]

Is it a fuel pressure gauge? Typically those vacuum gauge/fuel gauge combos are for carburetor fuel pressure. As a result, they only read up to about 10 psi or so. Your oil pressure could (possibly) be as high as 80 psi. Likely it is not, but as a safety consideration, it is a very poor idea to pressurize your fuel pressure gauge like that (read: do not do this). Not to mention, the fuel pressure gauge was not meant to handle oil.

As for hooking it up, I'm not exactly sure how you would plumb that gauge in. Most of the aftermarket dash gauges come with all that gear included. The typical location of the stock oil pressure sender is on the drivers side, towards the front of the engine, behind the fuel pump.

Good luck.