Can a bad oil pressure sensor shut down the car?

[PQ]

What all will I have to pull off to change the pump?

[Mr Twisty]

As far as the original question, if the ecm didn't shut the motor off, I would assume the Camaro will run with zero pressure.

A sensor, shorted wire or a bad ecm is the only thing that can throw a code, but even if your gauge shows good pressure I'd double check it... AND replace that sensor asap

[litle88]

Pulley
Water pump
Timing cover
Pump

But start with the OP sensor if it doesn't change then it's your pump.
What melling is on it? Who installed it?

[Mr Twisty]

Originally Posted by PQ

What all will I have to pull off to change the pump?

Is the gauge showing low pressure? Sorry, I may have missed some info. but if pressure is ok leave the pump alone and replace the sensor

...gauge reads low? or cel reads low?

[PQ]

Originally Posted by Mr Twisty

As far as the original question, if the ecm didn't shut the motor off, I would assume the Camaro will run with zero pressure.

A sensor, shorted wire or a bad ecm is the only thing that can throw a code, but even if your gauge shows good pressure I'd double check it... AND replace that sensor asap

Originally Posted by litle88

Pulley
Water pump
Timing cover
Pump

But start with the OP sensor if it doesn't change then it's your pump.
What melling is on it? Who installed it?

Not sure exactly what Melling. High Volume Melling is all the order said.

Vengeance installed it.

[Mike Norris]

I got your PM so here is my 2 cents. First things first, do a manual oil pressure test with an external gauge to verify if the oil pressure is actually low or you are just getting a bad reading.

If the pressure is actually low, then it could well be an oil pump or pickup issue. If it is good it could be a simple oil sender issue.

Hope that helps.

Mike Norris

[CamaroLoco]

What is considered "low" oil pressure?....PQ said his was at 15psi.....when my engine is warmed up, my gauge reads 15psi at idle.
*
I've always considered this to be within normal limits. I have a melling as well but have never thrown a CEL.

[PQ]

Originally Posted by Mike Norris

I got your PM so here is my 2 cents. First things first, do a manual oil pressure test with an external gauge to verify if the oil pressure is actually low or you are just getting a bad reading.

If the pressure is actually low, then it could well be an oil pump or pickup issue. If it is good it could be a simple oil sender issue.

Hope that helps.

Mike Norris

That's my plan Mike. Thank you.

Originally Posted by CamaroLoco

What is considered "low" oil pressure?....PQ said his was at 15psi.....when my engine is warmed up, my gauge reads 15psi at idle.
*
I've always considered this to be within normal limits. I have a melling as well but have never thrown a CEL.

Mine is reading as low as 5 psi when hot actually. And around 30 driving on the interstate.

[SSDan]

Originally Posted by PQ

That's my plan Mike. Thank you.

Mine is reading as low as 5 psi when hot actually. And around 30 driving on the interstate.

Weird how these things can be so different from one car to the other. I have the Melling Hi-vol pump and even when the oil is at its hottest like today (air temp= 100 degrees) my pressure was at 30 idling and 40+ while cruising. PQ you're overall low numbers would worry me though. I'll think good thoughts and cross my fingers that you have only a bad sensor.

[PQ]

Originally Posted by SSDan

Weird how these things can be so different from one car to the other. I have the Melling Hi-vol pump and even when the oil it at its hottest like today (100 degrees) my pressure was at 30 idling and 40+ while cruising. PQ you're overall low numbers would worry me though. I'll think good thoughts and cross my fingers that you have only a bad sensor.

My oil temp stays over 230 degrees on a hot day.

Don't have an oil pressure gauge and all the parts stores are closed now. I'll do it Friday. I'll have to work all day tomorrow and I bowl after at 7.

Bad thing is Bonnies Differential is grinding again and will need replacing soon. Ugh.............

[thahemp]

Originally Posted by PQ

My oil temp stays over 230 degrees on a hot day.

Don't have an oil pressure gauge and all the parts stores are closed now. I'll do it Friday. I'll have to work all day tomorrow and I bowl after at 7.

Bad thing is Bonnies Differential is grinding again and will need replacing soon. Ugh.............

A fellow Thursday night bowler. Anything that happens on thursday.... "ain't nobody got no time for that!"

On topic though... you might see if you can rent/borrow a mechanical gauge to check things with from the auto parts store just to make sure everything is ok for real. You might be able to turn the light off with a new sensor, but you'll sleep better at night having actually verified that your pressure is fine.

[PQ]

Originally Posted by thahemp

A fellow Thursday night bowler. Anything that happens on thursday.... "ain't nobody got no time for that!"

On topic though... you might see if you can rent/borrow a mechanical gauge to check things with from the auto parts store just to make sure everything is ok for real. You might be able to turn the light off with a new sensor, but you'll sleep better at night having actually verified that your pressure is fine.

Agreed.

[PQ]

Mine had been long starting. Especially when hot. Interesting here.

http://autorepair.about.com/library/a/1/bl526.htm

Q. It's my understanding, that when electric fuel pumps became the norm, car makers needed to put some kind of safety switch on the fuel pump to shut it down in case of an accident. Ford uses the inertia switch. GM I guess uses the oil pressure switch. If the oil pressure drops below 3 psi, it shuts off the juice to the fuel pump. Is that right? I was looking at a wiring diagram on an 1988 Chevy, for the fuel pump, It seems there are two hot wires going to the fuel pump. One goes through the oil pressure switch, the other through the fuel pump relay, and it doesn't appear that they are connected. If the oil pressure switch can't shut off the juice from the relay, what good is it? I guess I could be mis-reading the wiring diagram. What do you think? Also does Chrysler and the imports also use safety switches?

A. All fuel injected cars have some type of fuel shutoff in case of an accident. In the case you cited, the oil pressure switch does not, in itself, shut off the fuel pump. It sends a signal to the computer and if certain conditions are met, the computer will shut off the fuel pump. The primary way the computer knows that the engine is running is from a reference signal from the distributor. The ECU will not allow any fuel supply until it receives distributor reference pulses. As a backup system to the fuel pump relay the fuel pump also can be energized by the fuel pump switch and engine oil pressure sensor. The sensor has two internal circuits. One operates the oil pressure indicator or gage on the instrument cluster, and the other is a normally open switch which closes when oil pressure reaches about28 kPa (4 psi). If the fuel pump relay fails, the fuel pump switch and engine oil pressure sensor runs the fuel pump. An inoperative fuel pump relay can result in long cranking times, particularly if the engine is cold. The fuel pump switch and engine oil pressure sensor energizes the fuel pump as soon as oil pressure reaches about28 kPa (4 psi).
In general most imported cars use the Air Flow Meter to determine if the car is running. If the engine is running, air is being drawn in. If the air flow stops, it's assumed the engine is stopped and the fuel pump is shut down. In older vane type AFMs, there were a set of fuel pump contacts in the AFM itself. Now the ECU shuts off the pump. Some use a signal from the distributor or Crank Angle Sensor.
Chrysler uses an Automatic Shut Down relay and the fuel pump relay to shut off fuel. If the ECU does not get a signal from both the crankshaft and camshaft sensors within one second of engine cranking, the ECU deactivates the fuel pump and ASD relays, not only shutting down power to the fuel pump, but shutting down the injectors as well.

[Mr Twisty]

Originally Posted by PQ

Mine had been long starting. Especially when hot. Interesting here.

http://autorepair.about.com/library/a/1/bl526.htm

Then my assumption would be that GM now uses crank position sensor to tell the ecm the motor is running. Low oil pressure will likely not shut the motor off until it freezes up.

If anyone knows for certain please chime in, that's good info to know.