i have a 94 3.4l and have searched and saw a bunch of threads on "high oil pressure", but my problem is that the last year i have had my car the oil pressure was allways between 20-40 psi, and the other day i got on it getting onto the freeway and now it is consistantly reading 60-80psi. i have been listening to the enginge and everything sounds good. (no spun bearings, or valve knock)

is this a bad thing now that i have a higher oil pressure? like i said it seems to run fine, i just want to make sure im not going to blow a seal or something.
thanks!!!

 

Hopefully it’s just your gage acting up. Anytime you get a "change from normal" oil pressure it’s not a good thing. If you went from 30ish PSI to 70ish something is plugging up somewhere. As a general rule oil pressure is a result of how good your pump is and how much bearing clearance you have. To raise pressure you have to get a better pump or less bearing clearance.

Change your oil and use a good filter. You may want to cut your old filter inhalf and see whats in there.

 

i agree

 

When the gauge reading changes suddenly the first thing to check/replace is the sending unit. The sending unit has a diaphragm that is exposed to oil under pressure and the diaphragm is connected to a small potentiometer (variable resistor). Because oil pressure varies constantly while you drive the potentiometer is always moving and it wears out. This potentiometer is the thing that provides the pressure info (electrically) to the gauge. Also, the diaphragm can rupture which allows oil to leak into the potentiometer part of the sender. This will change the resistance values and, therefore, gauge readings.
The oil pressure sender is a long sucker on the 3.4. It is screwed into the oil filter adapter right above the filter. After having bad luck with a few auto parts chain switches/senders I buy mine from a GM dealer. A bit more money but worth it.

 

if you have access to one check with a mechanical gage. after i changed my sending unit the pressure quit changing. mine would jump about 20 lbs as well but would jump back down after a while. does not do that now. i broke the original while installing the motor.

 

Before the rebuild my pressure stayed pegged at 120 and would flutter. During the build, the sending unit and oil pump were replaced. Now it stays a fairly steady 60, but still flutters every once and awhile. I'm assuming it's the gauge itself that's a little messed up. Seems common for the sending units to go bad. I stopped paying attention to the fluttering.

 

I really need to type more. I would guess that 98% of the cars that showed up at the dealership with and complaint of a bad oil pressure reading and NO other issues end up needing a oil pressure sending unit, gage or they have a wiring issues.

When you see a work order that says Oil pressure hi/low and "xxxxx" is when the real problems start.

 

its ur oil sending unit. mounted of the front of te engine. the random sensor protruding out lol