i have a 93 blazer with a vortec 4.3 in it. the problem is my digital dash is showing no oil pressure, my dipstick is showing nothing on it, ive dumped probably 8 quarts in it, and the servise engine light is on. ihavent checked the oil pressure switch because i cant find it, i havent checked the dipstick tube to see if its fully in the block, and i havent checked the oil pump yet. any thoughts on what might be wrong? all help is greatly appreciated.

 

i also had someone tell me that the dipstick tube might be rusted out and the dipstick isnt getting into the block

 

[sm=welcomesign.gif]to the Forum. All the possibilities you mention are valid (although I can't imagine how the oil pump would come into the situation since it is inside the oil pan) and you will need to check each of them along with leaking from the valve covers and oil pan gaskets. The oil pressure sending unit should be on the top of the motor at the rear. Over what period of time have you put the 8 quarts into the engine? Have you seen any blue smoke from the exhaust?

 

there was no leaking anywhere and the eight quarts i put in in a hour period so its stilll has that much oil in it, and nothing is showing on the gauge or dipstick

 

The standard 4.3Loil sump is designed to hold ~5 quarts. Don't run the engine with 8 quarts of oil in it!That oil has to be somewhere. How long have you had this truck and when did the no oil/no pressure issue begin?

 

How long is your dipstick?? 8 quarts will likely fill it up to the point of having the crank sitting in oil!!

 

i havent been running it with that much in it. its been sitting. and the dipstick is stock size but it doesnt read anything. ive had the truck for about a month and the problem started about two days ago. last night i took it to advanced auto parts because autozone doesnt have a reader that with tell me the codes and at advanced the reader couldnt read it. so now i have to check them myself with the wire to the two prongs. when i took it to advanced i could feel it in the pedal how rough the engine was running. i know enough about trucks like this because i used to have a 91 jimmy 4.3 2 wheel drive nut this has got me stumped. im gonna change the oil today and put 5 quarts in it and change the filter and check the pump. also i have no idea where the oil sending unit is. and idont knowwhat the oil pressure sensor looks like.

 

i just checked the codes and the computer is flashing a code 23 at me. does anyone know what this means?

 

According to this website it means "Intake air temp sensor error (low temp indicated)", but Ican't imagine that having anything to do with your problem.

 

The oil pressure sending unit is located on the rear lifter valley rail near the inside rear corner of the driver side valve cover. It should have a stand pipe, then a 90* elbow, then the sending unit facing towards the brake booster.

Please use the edit feature to add information to your post if another member has yet to reply instead of posting consecutively. Thanks

By stating that you have a vortec motor, I am assuming you have the CPI motor (vin W) and not the TBI (vin Z). It's a common misconception, but the vortec cylinder head design dates back to the original 4.3L development. So all 4.3L v6 engines are vortec engines, but it wasn't until '93 with the introduction of the CPI motor that it became a marketing name.

Code 23 - Inlet air temperature sensor signal showed an air temperature of -29F for 4 seconds.

I would say that your IAT sensor is unplugged or malfunctioning. It should be right near the elbow in the inlet pipe ahead of the throttle body.

I type too much! Rich beat me.[&o]