Dummy Hot Light

[Shamu70]

Goes on when you start the car (70 Newport) and obviously goes off shortly after. But lately after a calm cruise it will flicker when I’m backing the car into garage.
If oil pressure were an issue, would that make it flicker? Or would the oil light just come on.

 

[halifaxhops]

Should be a low oil pressure light (on under 5psi) I don't believe it has a hot light. put a test gauge on it and see where it is at idle. With the engine hot! The sender can be on its way out also and just coming on at a higher pressure. I would get a good known reading for piece of mind.

 

[mr. fix it]

What weight of oil are you using?
An old tired engine will show signs of this but don't be fooled by this if it is the oil pressure light.
It may be a defective oil pressure sending unit.

 

[Big_John]

Goes on when you start the car (70 Newport) and obviously goes off shortly after. But lately after a calm cruise it will flicker when I’m backing the car into garage.
If oil pressure were an issue, would that make it flicker? Or would the oil light just come on.

Let's assume you've checked your coolant level... You have done that? Right???

Since we are talking about the "HOT" light, and not the oil pressure light, it either has to be the engine running hot or the sender or wiring is faulty.

A lack of oil pressure for an extended time can cause overheating, but by then, you've caused some damage and the lifters would have started clattering etc. In other words, you are going down the wrong road with that cause.

So, back to the "Hot" light....

Really, the best way to diagnose this is with a temperature gauge. IMHO, these cars should have an oil pressure and a temperature gauge added. A voltmeter is nice too. I always suggest a good set of electrical gauges to compliment the existing idiot lights. They are easier to hook up than the mechanical style and will give you all the info you need.

If you don't want to do that, a hand held infrared thermometer can tell you a lot too.

But then again, it's just happening when you are backing the car into the garage. It could just be a shorted wire that is dragging against a shift linkage or something dumb like that. Easy enough to check the wiring. Start at the sender on the water pump and work your way back. See if there's any cuts or breaks in the insulation.

 

[Shamu70]

I use Royal Purple 20/50; engine is a 493 that was built by previous owner maybe 8 years ago. Runs fantastic. I know it’s not overheating because gauge reads 180 & overflow tank was very low.
If I get an oil pressure gauge, where’s a good place to plug it in? Thanks for your input guys.

 

[Shamu70]

Yeah, a shorting wire was a thought too. I always panic & expect the worst. I’ll check that also.

 

[Big_John]

I use Royal Purple 20/50; engine is a 493 that was built by previous owner maybe 8 years ago. Runs fantastic. I know it’s not overheating because gauge reads 180 & overflow tank was very low.
If I get an oil pressure gauge, where’s a good place to plug it in? Thanks for your input guys.

If you look at the existing pressure sender, you can either tee it off there or look on the opposite side of the engine and you'll see another pipe plug and you can tap it there.

Check the actual level, not look at the overflow tank.

Again, if you are having an oil pressure issue, it's not going to make the "HOT" light flicker.

 

[halifaxhops]

Seriously borrow a testing oil pressure gauge and see where it is at. I have had aftermarket oil pressure gauges way off also. And also faulty oil pressure sending switches that came on with 15lbs also.
Also to help which light is actually the issue?

 

[cbarge]

As John said.FOCUS on the temperature NOT the oil pressure

 

[Shamu70]

Sorry I haven't responded in a while. When I was changing spark plugs I must've upset a comfort spot for the Hot Light wire; it was a short. Happy again, but happier when it's breathing in air below 70 degrees.