After changing oil pressure sensor engine will not stay running?

Hi,

Is there an issue with oil pressure? If it is very low, it will shut down the engine. Was this happening when the old sensor was in it? If not and you replaced it because of a leak, you may have gotten a bad sensor.

Let me know.

Joe

They just told us that the truck had a bad oil pressure sensor so we fixed it 2times times. then it still wasn't reading so we start moving the wiring around and it jumped up to 80. so we replaced that and nothing, it won't even start now. When we got it before fixing it wasn't reading but it drove like a champ.

Hi,

I just read through everything I could find in the manual. Many of these vehicles have a fuel cut-off if the oil pressure drops. It doesn't appear this one does Please confirm this is the V6 engine and not the V8.

Now, since the fuel cut-off isn't affected by oil pressure, we have to check for spark to the plugs and fuel to the engine. The easiest way to do this is to see if it starts using starting fluid and then stalls after a couple of seconds. If it does, then it's likely fuel-related. If the starting fluid makes no difference, then it's likely ignition-related.


If you are uncomfortable using starting fluid, here are two links that explain how to check fuel pressure and ignition spark:


https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator


https://www.2carpros.com/articles/how-to-test-an-ignition-system


Try that and let me know what you find.

Take care,


Joe

It's the v8 engine. It's a 1500 z71 5.3 liter.

I don't know why it says Chevrolet Trailblazer it's a 2003 Chevrolet Silverado.

Hi,

Okay, that makes a difference. LOL Do me a favor. Disconnect the oil pressure switch. At the connector, there will be a gray wire. With the key on, there should be a 5v reference to it. Check that and let me know if you have it.

Joe

Are you saying the whole sensor or just the wires?

Hi,

Just the connector. The sensor doesn't need to be removed. I want to make sure we are getting power to it since there was a wiring issue.

Let me know.

So unplug it and start car?

I don't have a volt checker.

You don't have to start it. Simply turn the key to the run position. Use a test light if you have no voltmeter to see if it lights.

Let me know.

Take care,

Joe

I don't understand what you mean by test light.

I don't have a test light either. Are you in Michigan?

Hi, Hope.

I'm near Pittsburgh. I wish I could be there to help. Listen, since it won't start at all now, let's check to see what is missing that is causing the engine not to start.

Since it was running fine, either we lost fuel or spark to the plugs. Take a look through this one link and let me know if you can perform what is asked. If you can't, get a can of starting fluid and see if the engine starts for a couple of seconds and then stalls. If that happens, then we know it is a fuel-related issue. If the starting fluid makes no difference, then it is likely ignition related.

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Let me know if you are comfortable doing one of those things.

Take care,

Joe

PS: Hang in there. We'll get it running.

It was wiring that was back by oil sensor. They were copper wires touching. We unplugged the oil sensor and it runs perfect.

We rewired the wiring and it's good.

Hi,

Excellent job. I'm glad you got it fixed. Since there was a short, the fuel pump wasn't being turned on. Does the new sensor provide accurate oil pressure at the gauge?

Let me know.

Joe

No it doesn't.

Hope, what is the gauge signaling? Does it work at all?

Joe

A little past 0 when plugged in, but right now it's not because it's unplugged.

Hope,

I would get a mechanical gauge from a parts store and confirm oil pressure isn't low. If it is, that can lead to other issues.

When I say a mechanical gauge, it is for testing only. As mentioned, often times a parts store will lend one to you.

All you do is remove the "New" electric pressure sensor and screw in the mechanical one. That way, there are no electronics that can cause a false reading.

I attached the manufacturer's oil pressure specifications below. The pressures indicated are at the low end of things, so it should be a little higher. However, as long as it is within the specs, it should be fine.

Let me know if you are comfortable doing that.

Take care,

Joe