sup people a while back my car thermostat had messed up an the radiator coolant was coming back through the resivouir (back up coolant) since then i flushed the radiator an put in a 160^ thermostat ,but car doesnt run like it use too , i already took the car to autozone to get scan an no codes came out , a local mechanic told me its the heads gasket gone out due to the overheated of the heads, so he just told me that the head gaskets need to be replaced thats it !! any suggestions would help

3.8 pontiac grand prix GT 1999 107,450 miles on car

First, what exactly is the car doing that leads you to believe that there is something wrong? A 160* thermostat is too cold, particularly for a GT. I would personally not go below 180*.

Next, is your oil milky looking after you shut off the car and check it? Is there a loss of power or something? What did your mechanic do to determine the head gaskets needed to be replaced.

__________________
Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

When you start the car is coolant still being forced out of the reservoir or is bubbling ?
It could be a cracked head or gasket and one of the cylinders is acting like an air pump and overpressures the coolant system shoving the antifreeze out leaving only air space instead that leads to the engine overheating.

it was weird cuz my temp needle never got to the hot part lol . but i heard the resouvir garrling an returning the coolant !! but since then i took off the radiator an got it flushed clean u name it ,changed the thermosta to the 160* since that happen my car feels a loss of horsepower, i checked the oil looks good not milky or burnt .i want to take the car to the dealership to run a full diagnostic test , cuz in my town all the mechanics wana screw u over with the price to fix it an labor an stuff so i dont know wut to do , but right now so far the car does not heat up or nothing like that, just that it does not pull as hard as it use too