[stonedstooge]

Paging Jasonsauto or any other car expert:

I'm having trouble with the cooling system on my 96 Trans Am with the LT1 engine.

The car runs fine on the highway. I have an OBDII hooked up and the temperature will range between 165 and 170 on the highway. When I return home, I have to drive about 3 miles of gravel. The temperature will start to rise when I drive less then 30 miles an hour.

The last 2 times I've driven it home, when I've gotten to my garage and backed it in, coolant starts gushing out of the coolant reservoir. Both times the temperature has been between 190 and 200. The fans on the LT1 are not supposed to even kick on until the temperature reaches 218 and 235 (2 fan system)

If I start it up and let it idle, the same thing happens. Temperature climbs, it gets around 190 and coolant gushes out.

The other day I tried an experiment. The coolant was about 6 inches below the neck of the radiator from lost coolant, so I started it up with the radiator cap off and let it idle. When it reached about 130 the coolant began to rise. At 150 it was up to the neck of the radiator, so I stuck a funnel in the radiator. At 160 it was into the funnel and at 180 (when the thermostat should be open) it was coming over the top of the funnel so I shut it down.

Last fall, I used a flush and changed out the coolant. This year, I've changed the thermostat, taken it back out and checked it in water on the stove and it opens fine. Changed the radiator cap and replaced the bottom radiator hose as it rubbed on one of the pulleys and began to leak.

It looks like the coolant is coming out of the engine as it should, but is not going back into the engine. I also noticed my temperature gauge on the dashboard jumps around and never seems to be stable.

Any ideas? Thanks for the help