Where do I find one for my car? I think mine went bad. I came up to a stop light and my oil pressure plummeted and my low oil light came on. Now every time I'm at idle my oil pressure sits right on the red line, but goes back to 30 when I'm at cruising speed. Part numbers are good and if its listed under a different name that might help as well. I've looked at Advance auto's website as well as Orielly's and only found an "oil pressure switch"

 

When i got my car the sending unit was bad. IT would stay pinned for a long time and every now and then go back and read the pressure. We got the new sending unit from the dealer. Was alittle tricky to install...my dad got also borrowed a special tool that clamps it and puts it on, without that he said it would have been pretty tough to do. He used to work for chevy/pontiac in the 80's so hes no novice with these cars...

 

The factory ones measure 1 3/16" but all the part store ones I have found to be 1 1/16". So you'll need two special sockets.

Did you say "low oil light?"

 

Everyone gets mixed up on this issue because everyones car had a different location. Go look right near your fuel filter see if you have one there. Then see if theres one on the back of your intake manifold? Someone can explain the location of the second one. You either had both of them. Or just the one combination above your oil filter.

Try the AC Delco website.

 

I'm pretty sure there is nothing near the fuel filter. I did check out AC Delco's site and they only had connector for the oil sensor. Am I going to have to have this fixed at a stealership? Is it safe to drive the car without making sure its this sensor? Uuhh... yeah low oil light, I checked the oil its fine.

 

crrllmich accidentally put fuel filter. He meant oil filter. The other location for oil pressure sending unit is in the china wall of the intake.

 

THe low oil light has nothing to do with the oil level. It comes on when a lack of oil psi. any parts stor will have the oil pressure sender and most can order the socket or you can get on at Sears or mac snapon bluepoint ect ect. When was the last time you did an oil change? and if you replace it and the same thing is happening you got a oil pump worn out or the bearings are too worn.

 

Oil change probably 1000 miles ago. I looked in parts stores and whatnot and can't find anything but an "oil pressure switch"

 

naaa that's like gm's version of fords rollover valve, (engine cuts out if not making a certain psi or something like that).

Should be able to find a oil pressure sending unit..... Mine is down near the filter too.

Maybe we are using different terminology than we need, do any of you have a hanes they could look it up in by chance?

 

I looked it up in my service manual and it has two references to the same piece one is an "Oil Pressure Sensor" the other is an "Oil Pressure Switch" It does not tell how to replace it in the book. I think I've got the right part. I'll be replacing it tomorrow morning and then I'll let you know how it turns out.

 

the oil pressure swith and sender are one and the same, should have a 3 wire conector, only sensor hooked up to a engine oil pressure. Earlier TBI's have it behind the distributor on the back of the block and later one have it by the oil filter. And yes it will cut the fuel off with no oil psi on start up. Don't ask how I found that out.........

 

Who said the low oil light has nothing to do with the oil level? If your oil level is low, and you come up to a stop and loose pressure, Your low oil light will come on!
The oil switch your talking about is known to third gen. F-bodies
as a back-up switch for the fuel pump when the relay goes bad to signal the pump to run when the computer see's oil pressure.
Evidently, the switch your refering to must have a different perpose being your dealing with an Oldsmobile. Why not try calling an Oldsmobile dealer and talk to the service manager or stop by the dealer and talk to the parts dept. I've never been charged for asking a question and the answers are free! They know more about your car than a guy behind a counter at a discount auto parts store. The oil pressure gauge went bad in my f-bird and when I priced the replacement it was over 50 bucks! I bought a direct oil pressure gauge for like 10 bucks and found it at 40 lbs. constant from idle on up.

 

Yah i had a wierd fuel problem with mine that it wouldn't turn the pump on until the engine cranked sufficient oil psi on startup swapped relays and i was good to go wierd stuff..

 

if the oil level was that low it would come on every time he went around a corner and hit the gass too, and lots of GM cars have " Oil level sensors" in the oil pan to let you know your low on oil.

This is how I know the basic GM pressure switch works on my TBI. Orange wire 340 comes from the battery then the fuse on the passenger wheel well and then splits goes to E on the Relayand The pressure switch and then splits again and goes to 2 spots on the ecm B1 and C16. G from the ALDL goes to D on the relay with red wire 490, when the relay is not powered this will contect D to A on the relay and you can jump off the pump. Now Dark green and white wire 465 goes from ECM A1 to C on the relay this is how the ECM turns on the the relay to turn the pump on. B on the relay is a black and white ground shared with ECM A12. When the ECM turns on the relay E is contected to A send in power to Tan and white wire 120, the fuel pressure switch will take power from orange wire 340 form the battery to tan and white wire 120 by passing the relay. Tan and white wire 120 also goes to B2 on the ECM to monitor Voltage. shortly after start up the ECM will cut off power to Darkgreen and white wire 465 is no Voltage is found in tan and white wire 120 it will not send more power to darkgreen and white wire 465, killing the fuel and turning off the motor. If the car has oil presure Tan and white wire 120 will have power and all will go on and ECM will once again send power to the relay.

If it does not work that way plz prove me wrong so I can know what is right

 

Sheet fire dude! I can't compete with all that color coded jargon!
But I do have one question, how come when his low oil pressure light comes on and the gauge drops to 0 his motor keeps running? Just because it works that way on your firebird doesn't mean it's the same for Oldsmobile. Perhaps the low oil light just comes on automaticly because of the bad reading from the oil pressure gauge and not because of actual loss of pressure. I know that on my f-bird that it has an oil pressure sending unit and an oil pressure switch and even if the oil pressure sending might go bad, the comp. still see's oil pressure from the switch.
Being that the parts store only shows a switch, it may do double duty and even though the gauge is screwing up it's still allowing the engine to keep running. I'm confused now! I've always thought a sending unit and a switch were two different things but, someone said that his had 3 wires connected. I guess it would be easier to call it a "switch" than a "oil pressure sending unit switch" huh.

 

10222130 is the part number for it. You can look it up on AC Delco's site. I really wish my service manual told me how to replace the damn thing, I'm going into this blind. The actual name for the part is Fuel Pump/Oil Pressure Switch

Edit:
After searching through my service manual for an hour I found it.

"The oil pressure sensor/switch is threaded into the engine block, above the oil filter.

Remove or Disconnect
1. Negative battery cable.
2. Raise vehicle.
3. OIl pressure sensor/switch electrical connector.
4. Oil pressure sensor/switch

Install or Connect
1. Oil pressure sensor/switch
2. Oil pressure sensor/switch electrical connector.
3. Lower vehicle.
4. Negative battery cable."

 

Good news, it was just that sensor. Turns out the seal on it broke and it was dumping oil into the electrical plug.

 

Exactly what it is on a 3 gen F-body. Fuel pump oil pressure switch. Just like my 88 formula. But, My oil pressure sending unit is seperate from that switch. Is your oil pressure gauge working now?

 

Only as good as it came from factory, which means it reads about 50 instead of what should probably be around 30psi.

 

new to these forums just picked up a 92 rs 25th anniv yesterday but all gauges on it work but the oil pressure gauge it usually stick at 30 till its warm then it operates properly anyways before i go out and buy a new sending unit could it just need to be cleaned maybe gumbed up inside?

 

newbie question, trying to diagnose a problem on my fathers 92 RS: if the oil pressure switch thats above the oil filter were to go bad, could that prevent the car from running?

 

No? But then again...if the ECM is reading 0 oil pressure doesnt it keep the car from starting?

 

thats what im trying to figure out. it'll run for a few seconds but then just die out

 

The oil pressure sending unit beside the dist. operates the gauge in the dash. The oil pressure switch above the oil filter tells the ECM that there is oil pressure.
I know that if your fuel pump relay goes bad, the oil pressure switch telling the ECM that there is pressure will allow the fuel pump to run but it will take longer for the engine to start because you have to crank the starter long enough to build oil pressure for the switch to tell the ECM and start the pump.
I'm not sure but it seems like if the ECM doesn't get a signal from the oil pressure switch even if the fuel pump relay is good. It could very well kill the pump thinking that there is no oil pressure.
The oil pressure switch is alot cheaper than the oil pressure sending unit and easier to change. Might try replacing it and see what happens.

 

after reading a thread from another guy who seemed to be having the same symtoms my dads car is, i think i may check the fuel pressure next. i have a feeling the fuel pump may be the culprit. still might replace the oil pressure switch anyways

 

He doesnt have the upper oil pressure switch. The 92 would have the bigger one with both gauges built into it by the oil filter.