when the car is cold the oil pressure is right in the middle of the guage. after it is at normal operating temp at idle it is at the hash mark right before the 0 mark. is this normal? at about 2k rpms its a little over the 1/4th mark. any help is more than appreciated!!

 

Very thin oil will cause low pressure. When it gets hot and/or old it will thin out. Does it do this even with new 5/30 weight?

Hal

 

its not as bad with new oil, however ive been using mobil 1 10w30 should i be using 5w30?

 

You might have a bad oil pressure sending unit.

Hook up a manual gauge

 

your not the only one with this problem. i put on a new oil pressure sending unit and the guage seemed to go up a little higher but not enough to even matter. the problem is somewhere else i guess. may be a worn out oil pump, clogged pickup, or just time to get her rebuilt.

 

10/30 is close enough.

Hal

 

Low oil pressure after a new sending unit could also be bad main bearings.

Not saying it is. But when I spun my main bearing my oil pressure was very low.

 

Rule of thumb is 10#'s for every 1k rpm when the engine is fully warmed-up. If you're worrying about a rebuild, just go with Mobil 1 20w50. Synthetic generally is a bit thinner than conventional dino oil, and will give a bit lower oil pressure reading. If you have appx. 10#'s/1k rpms, I wouldn't sweat it with Mobil 1...