Oil gauge

[MikeCon]

Oil gauge on my 73 302 quit working. Motor sounds fine. Gauge go bad?

 

[DirtDonk]

You have to test. There are wires and sending units that can go bad too. So far it’s only the oil gauge?

 

[MikeCon]

Best way to test?

 

[omureebe]

Put a manual gauge in place of the oil sending unit to verify you have oil pressure. Hopefully it shows pressure, then get another oil pressure sending unit since they're cheap after yo inspect and verify wiring looks ok.

 

[DirtDonk]

You can test the signal also. Do you have a voltmeter? With it set on the 20 V or less setting, check for a signal at the sending unit on the engine.
Or easier still just remove the wire and ground it to the engine. Then go in and turn the key on and watch to see if the gauge pegs all the way to full.

If it reads full with the wire grounded, then it’s probably just a bad sending unit.

 

[m_m70]

Or easier still just remove the wire and ground it to the engine. Then go in and turn the key on and watch to see if the gauge pegs all the way to full.

easiest by far......

 

[MikeCon]

Replaced sending unit. Plenty of oil pressure. 60lb cold. Have not run it much so don't know how much it will come down. Ordered 180 thermostat to up the temp. Runs around 130 now.

 

[DirtDonk]

At full operating temps it's typically between 30 and 40 psi hot. Depending on the oil viscosity and temp and engine wear and all that of course.
With a thick 20w/50 mine always read 70-75 when cold, 40-45 when hot. Whether hot was 160 or 180 did not seem to make a difference with that engine right up to it's ultimate 175,000 mile age.
I never had a 195° in that particular engine, but do in all my others.

Paul