GM 3.1 V6 cooling help needed

[bowtieman55]

1997 Chevrolet Lumina 3.1 V6. So my sister comes over yesterday and when she pulls into the yard, the car stalls and she coasts into the yard. She said it would crank but not start. The "low coolant" light was on. She got out, added some coolant to it, and she said it started. I get home and pop the radiator cap, and it's absolutely like wet dirt inside the radiator neck. The cap was coated with it. I pull the Coolant Level Sensor out of the radiator and it's completely gunked up, so I clean it out and re-install it. I go to flush the cooling system today, and the coolant isn't flowing (well)out of the radiator...I go and get a new water pump and thermostat and it's still not flowing out of the radiator. Once the engine gets a little heat in it, it starts flowing into the overflow reservoir. The heater is on high, and it's blowing cool air out of the vents.

 

[transman731]

that's quality dexcool for you. do a good flush, the issue with the 3.1 and 3.4 is intake gaskets. i see them every day. what usually happens is the intake gaskets blow and they overheat them and cause head gasket issues.
my suggestion would be to find a block tester and check to see if you have signs of combustion in the coolant.