Oil Pressure Gauge

I have a 1989 GMC Sierra 1500 5.7 ltr. Here lately as I am going down the road, my oil pressure gauge starts to move left. Eventually it just sits on zero and my check gauges light comes on. The gauge works fine for a while when I first start my truck when it hasn't been used for a couple of hours. But it never fails, after about thirty minutes, it drops again. Somebody told me it might be a ground wire or the gauge needs to be replaced. Any suggestions?? email me at [email protected] Thanks!

First things first, you need to verify the pressure with a mechanical gauge. If the pressure is good, the sending unit could be the cause to the problem.

//2000CAYukon

Thanks. I'll try that.

I have got the exact same thing happening on my truck. 98GMC Sierra K1500. If you find out what it was please let me know.

Did you end up replacing the sending unit?
I have a 96 with 183,000 and the oil gage will bounce irregularly while at idle. Do you think it is the same thing. How hard is it to replace to sending unit?

Hey guys i just had the exact problem, replaced the oil pressure sending unit and it fixed the problem completly!!

Hope this helps