After it's warmed up, my g3500 express 6.0L gas box truck's oil gauge fluctuates with acceleration. 40psi is the mid point on the gauge. At idle, its around 29psi, and 50 psi on the highway.

I've asked 2 separate dealership mechanics about it, both Chevy. One says its completely fine, the other says it should not be doing that. Ok........so which is it??

I've tried researching the reasons for this, so I know about the sending unit, pump, gauge itself, **** being clogged, etc.

The answers I'm not finding are.....could this be an indication of something more serious, like worn main/rod bearings......would that even be a symptom? I realize LOW oil pressure could be a sign.....but what about fluctuating?

 

What you are getting is normal. All of my Chevies have done that. Lower oil pressure at idle than at running speeds.

 

^^What he said^^

 

Mine does it also, and so did my Dodge van I had previously. No worries there.

 

one more for completly fine.

all positve displacement oil pumps will generate more pressure as the pump turns faster. So it will fluctuate with engine speed.

minimum oil pressure is 10psi for each 1000rpm engine speed
pressure of 90 or more is to high

 

have to agree also, the swing should not be huge. Lower at idle and higher at speed is normal for mine...

 

thanks everyone for the help