2004 K2500HD 6.0 oil pressure gauge problems

[OR VietVet]

I have been seeing the odd oil pressure gauge reading for a couple days. Was completely normal. I think the problem is a stepper motor. If it is, I will just get a new cluster from Digital dash solutions. I have a Foxwell NT710 scanner that will graph oil pressure readings. The graph is from 0 to 5. When I start the engine, it idles around .5 and you can see what happens when I rev it on the graph and at the gauge. The lowest the gauge reads is around 40 psi and then does climb while driving and if accel hard enough, it goes past 80 psi. When engine is cold and KOEO, the reading is around 40 psi.

Here you go:

 

[OR VietVet]

@89Suburban, it is gonna be a stepper motor and therefore I am going to customize the dash cluster at Digital Dash Solutions.

I sent the pic and the video to them. They were asking questions and a pic/video says it all. No engine noises though.

 

[Fless]

You could pull the custom cluster from your Tahoe and install it here to see how it acts.

Have you thought about disconnecting the connector on the sender to see what the gauge does then?

Back in 2020 I compared the Oil Pressure Sender Voltage with my gauge readings:



YMMV

 

[OR VietVet]

You could pull the custom cluster from your Tahoe and install it here to see how it acts.

Have you thought about disconnecting the connector on the sender to see what the gauge does then?

Back in 2020 I compared the Oil Pressure Sender Voltage with my gauge readings:

View attachment 445911

YMMV

Good idea on the cluster swap. They are so easy to do.

Thanks for the voltage/gauge comparison readings.

No, I had not thought of disconnecting the sender switch. I have a new GM sender and if I gain access to disconnect, I am going to change the sender.

Remember on my Tahoe build thread how I got carried away.

It looks like I am going to keep the truck and end up putting my Tahoe up for sale here at the forum.

UNLESS, my girl takes it over and we sell her 75k miles TrailBlazer.

I really don't think she will part with the 1990 K2500. She has had it close to 14 years and loves that truck.

So, everything is up in the air for now.

 

[Fless]

I'd be interested if you compare either cluster readings to the voltage readings to see how mine and yours differ.

 

[OR VietVet]

I'd be interested if you compare either cluster readings to the voltage readings to see how mine and yours differ.

If I do that, I will compare for you, but it does sound like a good idea, especially since it is so easy to do.

 

[Fless]

One other thing that comes to mind (think "scatterbrained" and I won't be offended) is that if the sender is compromised and leaking oil into the sender connector, that could be skewing the readings.

 

[OR VietVet]

Tomorrow is a "check it out day". Looking for leaks, I see none on ground, and hope to swap the clusters.

 

[OR VietVet]

@Fless, I think it is interesting that at 35 psi the voltage reads 1.69. 5 more, 40 psi and the voltage reads .17 more at 1.86 volts. Then at 45 psi, the voltage reads .20 more at 2.06 volts. Then 5 more psi again at 50 and the voltage jumps to 2.29 for a gain of .23 volts.

But when the psi jumps 10 psi more from 50 psi to 60 psi and the voltage only changes .12 volts to a total of 2.41 volts. Jumps 10 psi and the voltage difference does not climb as much as I thought it would. Do you know what the reason is for that?