flynhi

Vehicle: 99 C5 with 75k miles
oil and filter: Mobil 1
About 2k miles on this oil change

Idle oil pressure 38
Oil pressure at 2k RPM 63

This is about 15 psi higher than it has been for several thousand miles. What does this mean?
a. nothing to be concerned about
b. clogged oil filter
c. failing oil pressure sensor
d. the Mayan aliens are here.........

Your insight, pls

3boystoys

I vote for aliens.

coia96vette

It's the Mayans. The world is supposed to end tomorrow..

NukeC5

Have you allowed the oil to warm all the way up? Use the DIC to see when the oil reaches 200+ degrees and then check the pressures. The cooler the oil, the higher the pressure will be; and obviously the warmer it is, the lower the pressure will be.

flynhi

I understand this characteristic of dino oil but I thought that Mobil 1 has constant viscosity when cool or hot....

chassed

A...

johnson-rod

Those pressures sound normal to me.

Old Horsepower

No. Oil is oil synthetic or not. Thicker when cold thins when hot. Mine with synthetic 10W30 Idles cold at a little over 40psi. At operating temp about 30psi.

robert miller

Cold about 65 then warmed up goes to about 30 to 35. But I am also useing 20w 50 amsoil...Robert

_r2h

I use M1 0w-40 and usually see ~40 psi at idle, hot or cold.

K-Spaz

You don't say what oil you changed from or to. Mobile 1. Ok, Mobile 1 What? If you went from 5w30 to 15w40 or 20w50, then yea, it's normal.

C66 Racing

Nope - no synthetic is.

Straight from Mobil 1's website, the Mobil 1 5w30 viscosity:
100F: 61.7 cSt
212F: 11.0 cSt
300F: 3.1 cSt

Note that a 30 grade oil is partially defined as having a viscosity of 9.30-12.49 at 212F.

Also note that I check the oil websites pretty often and I think that this is a bump in viscosity for the Mobil 1. My recollection is that it was closer to 10 cSt at 212F not to long ago. It's possible Mobil 1 raised their viscosity a little and you are noticing that.