2021 Sierra Oil pressure issue

[Smoltified]

Recently my oil pressure gauge started going wonky, zero to 400, fluctuates at random times. When it first happened I immediately pulled over and checked for leaks, oil level etc. Truck seems to run fine, no knocking,  burning. Did an oil change about 3 weeks ago, with no issues. Now the gauge rarely works. This is over a day and a half. Thanks. 

[newdude]

3 hours ago, Smoltified said:

Recently my oil pressure gauge started going wonky, zero to 400, fluctuates at random times. When it first happened I immediately pulled over and checked for leaks, oil level etc. Truck seems to run fine, no knocking,  burning. Did an oil change about 3 weeks ago, with no issues. Now the gauge rarely works. This is over a day and a half. Thanks. 

 

 

Check engine light on?  

 

400, I assume you are in kPa so Canada?