I just bought a 1999 chevy blazer 4x4. i drove it +60 miles back home with no problems what so ever but after i did a basic tune up(spark plugs, plug wires, oil/filter change, thermostat(which i have to take back since its stays open), and air filter. I then drove it around town for a bit and all the sudden i lost oil pressure and didnt have any power when trying to accelerate so i eventually got back home with it and when i got back home from work(6 hrs later) i started it up to pull it in the garage and it had oil pressure again and was running normal.....


would the oil pump be going out for it to do that?

 

I would start with checking oil level and probably swaping out the oil filter for another brand filter

 

should i try thicker oil as well?

 

years ago I tried a "economy oil" in my car
I started my car in extremely cold weather to warm up
I kicked it out of high idle (carburated) and as soon as the engine RPM dropped the oil light came on
I drove back to work and changed the oil and filter again and never had a light issue again

I have been in the automotive parts trade for 20+ yrs
A few years ago a large company moved in selling cheaper filters and oil
I lost some sales but quickly got them back because garages had issues like this

I will only use OEM filters on my car and for the last 15 years Castrol oil

 

BTW it is possible the oil light switch is shot ,does it have a gauge as well ?

 

I used Fram TG3980 and Valvoline 10w-30 and im pretty sure its not the oil pressure sensor since when i first start it up when its cold it goes to 40 but after it sits it goes down and the rpm starts going down till eventually it stalls....

so i decided screw it and pull the motor and build it like i planned to in a few months

 

So I pulled my engine and tore it apart finding that i had spun bearings and i still cant figure out how happened...
i drove it +60miles home after buying it, next day i did a tune up( oil, plugs, etc) drove it 5 miles, came back home.
then i was heading to autozone to get me CEL codes checked and on my way there lost oil pressure lost power when trying to accelerate...


Have any one ever seen some thing like this and what could have caused it??

 

im kinda having the same scenario i bought a 99 zr2 4.3l vortec w vin had it for about 45 days spun a bearing we tore it down put a new motor in it i have driven it about 50 miles since the new motor lost oil pressure this morning on a four mile drive started to hear a slight knock before i noticed the loss of oil pressure parked immediately and had her towed, mine through out a few codes
none of wich have anything to do with the oil pressure my thought is i have clog in one of the cooler lines that's what i will be looking into asap probably will have to go back through my rods and valves as well now.. i would definitely be open to any other suggestions any one else has as well and will help to keep you posted if i come across anything that leads me in the right direction

 

The newer Fram Filter maybe your cause. They are junk & have been know to come apart & spread joy throughout the engine.