Oil gauge drops to Zero so the Low Oil gauge light comes on....and dings dings dings....SO annoying. My mechanic replaced the Oil Sending unit, but it is still doing it. He said if the new sending unit didn't stop it, it is probably in my panel. But none of the other gauges in the panel are messed up like this.

Doesn't seem to make sense. So if anybody has any tips for this fix (or at LEAST how to get the dang dinging to stop!) I would appreciate it.

Thanks

 

could be the stepper motor for the gauge, could be a bad sending unit even though you replaced it, ive seen bad ones out of the box. or the wiring to the sending unit.
just to be clear you are talking about oil pressure gauge and not low oil message. because there is a sensor in the oil pan that do go bad that cause low oil message.

 

If the gauge is activating AND the alert light and ding are activating, it's not a bad stepper motor. The 2 alerting methods are working independent of each other (another words, the position of the stepper motor for the gauge does not cause the light/ding to activate).
Both the stepper motor and the light/ding alert are responding to data coming from the PCM. This means your PCM is believing you have low oil pressure.
- Could be the wrong sending unit was used or the new sending unit is faulty.
- May need to inspect wiring, including pull the GM diagnostic info (I believe the oil pressure sending unit is a 2 wire connector, 1 wire to ground and I believe the other wire goes to pin 19 of the PCM, not sure if that is to the blue or clear PCM connector).
- If the wiring checks out, you may want to have someone attach a mechanic pressure gauge and see if that reading is similar/equal to what the PCM is receiving.
- You might have a physical/mechanical problem that is resulting in low oil pressure. I would be concerned to drive the car until this is resolve (oil starvation can be a good way to destroy an engine).

 

It is the oil pressure gauge. The oil is full. It registers 'normal', then registers zero! Replaced the oil sending unit twice, since the first time didn't fix the problem. My mechanic said if it continues to do this with the 2nd unit installed, there may be a problem in the dash. I would HOPE my mechanic tested it for me to see what else it may be. But who knows, maybe I need another mechanic.

 

If it is the cluster, the stepper motors are cheap to get off eBay and if you can work a soldiering iron, it's a pretty easy job. We have a step-by-step guide in the FWD Tech Info section.

 

Whoa! I just caught again that you commented that the car dings when the oil gauge acts up. This sounds like you have an issue that is NOT the cluster. If the stepper motor was bad, it has no impact on the ding-ing to alert you of an issue. This means the PCM is informing the BCM and the cluster that the oil pressure dropped, resulting in the 0 reading on the gauge and the BCM activating the audible alert.
When a stepper motor fails, it typically "hangs" in weird spots, it can also mover the needle off the actually gauge (depending on the gauge).

I would want someone to use a scan tool (like a Snap-On or a TechII or even a cheap bluetooth ODB-II unit with an app on a phone) and read the data stream from the ODB-II port for the oil pressure unit (as this is the actual data the PCM is seeing). At that point, you really have about three options:
- Bad computer PCM (which is not often, but happens).
- Bad wiring for the oil sending unit (such as a short or a break in the wire that connects/disconnects as you drive). This can be tested with a volt meter (either doing basic continuity tests, or I am sure the shop book has information on other tests).
- Actual oil pressure problem.

My money is on a wire or oil pressure problem.

 

Just wanted to make it clear that it is (for the most part) intermittent. Sometimes the dinging stops and the gauge reads normally. Then, bam!, it goes back to zero and the dinging starts again. It 'dings' more than it doesn't these days.

Thank you all for your suggestions!