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I need some advise/guidance. I repaired my cold start injector (CSI) fuel leak yesterday on my 1987 B2K. Restart and leak check was perfect. HOWEVER, as I was driving around I noticed my OIL pressure was low, staying from 22-27 lbs in idle and going as low as 7 lbs (and a RED indicator) under acceleration.
What I found:
1. Oil and Coolant temp= NORMAL See pics
2. PERFORMANCE= GREAT
3. NO ABNORMAL NOISES (LIFTERS. ETC)
4. NO smoky exhaust or leaks of ANY KIND (before or after drive)
5. Oil level= PERFECT (Full quantity before AND after drive)
6. Fuel is non-ethanol @92 octane
7. NO ECM THROWN
Because of the location of the sensor, I may have partially disconnected the single wire line to the sensor when dealing with the CSI fuel line. I read that a fully failed sensor will shut the engine down altogether.
My suspect is EITHER the sensor has partially failed or the connection is loose. THERE IS NO INDICATION of actual oil pressure loss OR ANY loss of oil.
FEEDBACK PLEASE...
Last edited by avcwo; 03-16-2016 at 10:57 AM.
Reason: Adding pics
If you have the FSM and I'd think you do. The values used for checking the senders/sensors are there. The sender for the gauge is different than the "switch" you're referencing. Do you know what the values were before the work you did? It's a single pin connection and "loose" doesn't normally change the display, either works or doesn't, could be wrong but should display.
In your FSM check first in the 8A section for instrumentation, likely 8A-82-xx It's in other areas in other year FSMs.
You want to be sure that you are having the right pressure. Don't listen for noise only. Do what I did. I took the sensor out (one by the filter since it was easiest) and do a test with a cheap mechanical gauge. Right or wrong pressure, lets see if the gauge is right first. If not, fix it. That is, unless you a Jonsing for a new engine and you are trying to break it so you have justification.
What would cause low oil pressure, yet have no temp/quantity/performance/codes?
Thanks!
Originally Posted by WVZR-1
If you have the FSM and I'd think you do. The values used for checking the senders/sensors are there. The sender for the gauge is different than the "switch" you're referencing. Do you know what the values were before the work you did? It's a single pin connection and "loose" doesn't normally change the display, either works or doesn't, could be wrong but should display.
In your FSM check first in the 8A section for instrumentation, likely 8A-82-xx It's in other areas in other year FSMs.
What would cause low oil pressure, yet have no temp/quantity/performance/codes?
Thanks!
First off, the pressure is just tied to the gauge so I don't think there is a code. You'd better hope there is no spike in temp because if there is, you may ran out of oil and the engine is cooking. Third, PLEASE DON'T ASK what would cause low oil pressure. All you do is drive yourself into an early grave. Figure out IF you have low oil pressure or not then worry. It could be a bad oil pump to a sump coming loose or bad gauge or whatever. Confirm it first or you are, as my old boss used to say "Borrowing tomorrow's problem".
I agree.....too much info can be an issue. I will check it out in-depth. My belief is that it's the sensor, considering all the other factors mentioned.
Originally Posted by aklim
First off, the pressure is just tied to the gauge so I don't think there is a code. You'd better hope there is no spike in temp because if there is, you may ran out of oil and the engine is cooking. Third, PLEASE DON'T ASK what would cause low oil pressure. All you do is drive yourself into an early grave. Figure out IF you have low oil pressure or not then worry. It could be a bad oil pump to a sump coming loose or bad gauge or whatever. Confirm it first or you are, as my old boss used to say "Borrowing tomorrow's problem".
I agree.....too much info can be an issue. I will check it out in-depth. My belief is that it's the sensor, considering all the other factors mentioned.
OTOH, we can speculate what it can be and have you change everything but the exhaust tip. It's not our money so we can be like the Government. Spend OPM freely.
What would cause low oil pressure, yet have no temp/quantity/performance/codes?
Thanks!
The FSM will give you "testing procedures" to confirm gauge accuracy, disconnected I believe puts it to 80, jumper to ground I believe 0. That should be in the same section of the FSM. To confirm engine oil pressure you need to check with a mechanical gauge ...
I agree.....too much info can be an issue. I will check it out in-depth. My belief is that it's the sensor, considering all the other factors mentioned.
Originally Posted by aklim
First off, the pressure is just tied to the gauge so I don't think there is a code. You'd better hope there is no spike in temp because if there is, you may ran out of oil and the engine is cooking. Third, PLEASE DON'T ASK what would cause low oil pressure. All you do is drive yourself into an early grave. Figure out IF you have low oil pressure or not then worry. It could be a bad oil pump to a sump coming loose or bad gauge or whatever. Confirm it first or you are, as my old boss used to say "Borrowing tomorrow's problem".
Screw it into the port for the oil temperature sensor goes and see if the numbers match with the readings your getting on the digital display. That tester has a VERY long hose so you can actually have the gauge up at the windshield and drive the car if you want.
Screw it into the port for the oil temperature sensor goes and see if the numbers match with the readings your getting on the digital display. That tester has a very long hose so you can actually have the gauge up at the windshield and drive the car if you want.
YES. The oil temp sensor is in the block close to the starter.
Not correct!! You have multiple points where the pressure can be checked. You have I believe the FSM and it will show you where the correct ports are to be used. The "look see" first hand will further familiarize you with the FSM>
That is a backup for the fuel pump relay. It closes when the oil pressure exceeds 4 PSI. You can disconnect it and the engine will still run normally (assuming the fuel pump relay works correctly).
That is a backup for the fuel pump relay. It closes when the oil pressure exceeds 4 PSI. You can disconnect it and the engine will still run normally (assuming the fuel pump relay works correctly).
Any idea why it requires a back up Fuel Pump Relay?
Any idea why it requires a back up Fuel Pump Relay?
There's only a "single" fuel pump relay.
Check your FSM for an explanation of how the circuit works. If you read it a couple of times it "might stick". There's likely multiple threads here explaining the operation with the diagram also.
03-16-2016, 09:41 AM
How to tell if a oil pressure gauge sensor is bad
