97 low oil pressure

1997 blazer 4 door ls 4.3 4x4

I feel like i can never win with my car i finally got it fixed then bam somthing else:banghead:

Im well aware the 4.3 have werid oil pressure. idle-20 ish driving 40 ish. and mine was the same. I would come to stop and it would drop to 20 lbs the sec i touch the gas right up to a steady 40 lbs. On the way home today i notice it got lower and lower from 40 while driving. It settle at 20 while driving. as soon as i would lift of the gas i would go to around 30 then back down to 20. If i get on the gas REAL hard it will go to 40 but as soon as the rpms drop below 3500, so would the oil pressure. I thought that this was a lil weird since it was never like this before.

When i came to a stop my best freind "check gauges" came on i look at the oil pessure. It was in the red :banghead: :banghead: :banghead: When ever i came to a stop i had to give it a lil gas about 900 rpm just to keep the pressure at 10lbs.

Oil level is good, I had a fram filter in and i just put in an ACDelco and nothing changed. The car runs fine.

I have NO idea whats what and wheres what in the oil system. Atleast interanlly of the motor.

I leave for school(6 hour hike) on saterday morning. Speedy responses would be very much appriecated Thanks in advance

Sounds like a bad oil sending unit.

thats what im feeling, How in depth is replacing one of these.

Well, do you hear any noises in the engine? With this low of pressure, you defiently would hear start-up knock, is there any? You mentioned you changed your intake gaskets, did you retourque the intake down to spec? Hopefully you just have a sending unit problem. Its not that bad to replace, hopefully thats your problem. Good Luck.

Well, do you hear any noises in the engine? With this low of pressure, you defiently would hear start-up knock, is there any? You mentioned you changed your intake gaskets, did you retourque the intake down to spec? Hopefully you just have a sending unit problem. Its not that bad to replace, hopefully thats your problem. Good Luck.


If i drive it for a while atleast 10 min and let it sit on low oil for 5 sec and then turn it off. WHen i turn it on it does tap for like 2-3 sec then goes away. If i turn it off again and then start it up it wont do it. almost like it needs to cool down slighty to have a start up knock, but not cold. And yes i did retouque them.

It sounds like you do have a oil pressure problem. For it to tap a little, oil is not getting to the top fast enough. It could be the oil pump pressure relieve valve is stuck and allowing to much pressure to exhaust. At this point, I would get a good engine flush (GM crankcase cleaner), flush it, drain the oil, refill it with oil, filter change, and see what happens from there. Good Luck.