oil pressure
2 Answers
If you have a lot of miles on it, you may be able to change the oil and use a heavier weight oil. For instance, if you are using 10W-40, switch to 20W-50 to see if it helps.
Silverado's have a problem with gauge clusters. One gauge will go then another. That's what happened on mine. The cluster is real easy to replace, on mine 4 screws and it pops out and one connector to disconnect and the new one just reverse the procedure. You won't find news ones just rebuilds so you have be sure not to damage the core as you have to send the old one back. They vary in price from where you would buy it from, so shop around. But that is my best guess.