97 blazer LS
4door 4Wheel drive

I have onwed my 97 blazer for about year and a half now, since i've owned it my oil pressure has been 40@ Idle and 60@ driving speed.

About 5 months ago my gauge started droping to 0 when i hit a bumb or turned hard. I ignored it thinking it was a short in my dash. i check my oil a few weeks later seen i was low so i changed my oil. I'm pretty sure i put Mobile one 10W40 in. went back to normal for a bit then my gauge started to move around, never below 35 PSI and all ways just below 60 while driving.

I just change my oil Mobile One 5w30 and as I all ways do i did a seafoam treatment, and today i chngend my Oil pressure switch.

started the truck up and my oil jump to 60+ PSI. i got it up to temp and to help 40+ @ idle and 60+ @driving normal heavy footed it got to all most 80.

I'm not sure if i messed something up when i installed the new switch or not. any clues?

 

The only real way to find out what is going on is to get a mechanical oil pressure gauge and measure the actual pressure.

 

Thanksthats my next step, i just drained my oil and refilled it again with exactly 4 quarts, thinking i may have had it over filled last time. it ran even higher this time around

 

Could also be ur oil pump acting up as well

 

I was hoping no one would say my oil pump, i don't feel like replacing it. but i was just reading some tother threads about the same problem so i'm thinking faulty oil switch, bypass vale, or clogged pcv valve.

 

Very well could be sorry to be the first to say oil pump lol

How many miles are on the motor ? and has it ever been rebuilt?

 

135k as from what i was told i'm the second owner so i'm pretty sure every thing is still orginal unless i have changed it.

 

At one time I had extremely high oil pressure in my 89 Jimmy 4.3 TBI to the point it would blow oil out of the dipstick tube if it was not seated. It would also pop out the PCV valve. I could not figure out what was going on for the longest time. I decided to rebuild my TBI unit and it turned out the the port on the TBI unit for the PCV system was totally plugged. So I had no crankcase ventilation. Once I cleaned out all the ports and re-assembled the TBI unit the Oil Pressure was normal.