I hope this is the right forum.

On the way to the jobsite today, I happened to glance down at the instrument panel and noticed oil pressure was around 40psi. I found it a bit strange since the oil pressure usually floats around 50-60psi. I gave the car some gas, and rather than the PSI going up, it remained at 40.

Within a few seconds, it dropped to 30. About a minute later, down to 20psi. I got kinda scared and took the nearest exit off the higheway and just then, oil pressure went down to ZERO Nothing at all regardless of whether I was giving it gas or not.

The place where I bought the car was about 2 blocks away so I literally shut off the motor and coasted down the street in neutral so as to not possibly cause any serious damage.

After pushing the car intothe parking lot and into the shop, we put the car on the hoist. My first guess (and hope) was that it was something small, like a possibly bad such as a malfunctioning sending unit.

I ordered a new sending unit from GM ($30CAD) and it arrived 20 minutes later. We replaced it but it solved nothing. Oil pressure still read zero.

The strange thing was, the car ran and idle'd fine. No signs what so ever that there was something wrong. No unusual noises, no studdering or loss of power. Nothing. Just no oil pressure.

We eventually hooked up an external oil pressure gauge (we would have done that first but my mechanic lent it out to the guy next door and he didn't show up till later)

and sure enough, it show the car making 40psi at idle. We let the car run for a while, reved it a few times and pressure went up a few psi.

I drove the car home at the end of the day, with the oil-pressure gauge in the car reading ZERO. Obviously, it doesn't work as the car is infact, getting oil-pressure. But even after the sending unit was replaced, shouldn't that have fixed the problem with the factory gauge? What other part has to be replaced? The gauge itself?

Also, is 40psi about normal for these cars? How about 45-50psi under WOT? Is that about the average?

I'm kind of worried that 40psi is a little low and since the factory gauge reads zero, I'm worried if there is a problem and the PSI drops down, I won't be able to tell untill it's too late and I destroy the engine.

Are there any tell-tales signs that the motor is down on oil-pressure? Some sounds/noises I should be looking for?

ANy input on the situation I'm in right now would be greatly appreciated.

Thanks in advance.

 

I hope this is the right forum.

On the way to the jobsite today, I happened to glance down at the instrument panel and noticed oil pressure was around 40psi. I found it a bitstrange since the oil pressure usually floats around 50-60psi. I gave the car some gas, and rather than the PSI going up, it remained at 40.

Within a few seconds, it dropped to 30. About a minute later, down to 20psi. I got worried so I immediately took the nearest exit off the higheway and just then, oil pressure went down to ZERO Nothing at all regardless of whether I was giving it gas or not.

The place where I bought the car was about 2 blocks away (luckily for me) so I literally shut off the motor and coasted down the street in neutral so as to not possibly cause any serious damage.

After pushing the car into the parking lot and into the shop, we put the car on the hoist. My first guess (and hope) was that it was something small, like a possibly malfunctioning sending unit.

I ordered a new sending unit from GM ($30CAD) and it arrived 20 minutes later. We replaced it but it solved nothing. Oil pressure still read zero.

The strange thing was, the car ran and idle'd fine. No signs what so ever that there was something wrong. No unusual noises, no studdering or loss of power. Nothing. Just no oil pressure.

We eventually hooked up an external oil pressure gauge (we would have done that first but my mechanic lent it out to the guy next door and he didn't show up till later)

and sure enough, it show the car making 40psi at idle. We let the car run for a while, reved it a few times and pressure went up a few psi.

I drove the car home at the end of the day, with the oil-pressure gauge in the car reading ZERO. Obviously, it doesn't work as the car is infact, getting oil-pressure. But even after the sending unit was replaced, shouldn't that have fixed the problem with the factory gauge? What other part has to be replaced? The gauge itself?

Also, is 40psi about normal for these cars? How about 45-50psi under WOT? Is that about the average?

I'm kind of worried that 40psi is a little low and since the factory gauge reads zero, I'm worried if there is a problem and the PSI drops down, I won't be able to tell untill it's too late and I destroy the engine.

Are there any tell-tales signs that the motor is down on oil-pressure? Some sounds/noises I should be looking for?

ANy input on the situation I'm in right now would be greatly appreciated.

Thanks in advance.

 

it sure sounds like your gage took a dump. its fairly common on old cars.

40 PSI at idle is more than enough. i would like to see it higher with RPM, say up close to 60 around 4000 RPM or so, if your oil is old then that tends to lower your pressure.
with a fresh oil change my motor does around 60 up around 4000 RPM, with old oil its down around 50 PSI at that RPM.