Under high rpm my oil pressure continues to climb (northward of 80psi) to the point of tossing a SES light on my C5. Does anyone know why it might be going this high and what might be good places to start looking at? I havent done a cam in it and its running Mobile 1 10w30 synth with a AC Delco filter.

Thanks.

 

please?

 

I use 10w40 oil in my LS1, which I beleive to be thicker, I'm getting between 30 and 50 psi. On idle is on 30 which is lower than it is usually, going to change my oil, think that may be my problem. I wonder if the oil is the problem, if the filter is fine. You have the standard belt system on the front dont you?, no overdrive pullys.....
Apparently the engine has smaller valleys for the oil to return to the bottom, than other engines like the 5.7 iron block. I wonder if some of these valleys are blocked. Perhaps try some oil flush aditive before you change the oil.

 

check your oil pressure switch, make sure its not broken

 

If the piston in the pressure regulator in the oil pump is sticking in its cylinder, the oil pressure may not be regulating properly. What happens is that when the oil pressure builds past about 60 psi (or 4 Bars or 400 kPa), the output pressure from the pump will press the piston hard enough against the coil spring on the other side to the point that the piston goes down in the bore of its cylinder to expose a slit opening. This slit opening dumps excess oil back into the inlet side of the pump and thus relieves/regulates the output pressure. Thick, vicious oil can have the same effect of raising oil pressure above the design max regulated pressure. This is true when the oil is very cold or if higher viscosity oil is used.

Another possibility is that you have an aftermarket oil pump which has been ported and/or the regulator spring has been replaced or shimmed to increase the pressure.

Another possibility is a plugged oil passage that causes the pressure to build.

All my best,

Steve