My gf has a 97 malibu. It is missing when it idles, and it is over heating. Its a strange miss tho it fells like the car is lurching forward, and it gets worse when you put it in drive. my first thought was the temp sensor, but the temp gauge doesnt go back down once you start moving. any help would be greatly appreciated.

 

That's not enough to go on. Worst case for a V6? It could be a lower intake manifold gasket failure. For an I4, it could be head gasket failure or cracked head. Check the oil for any sign of coolant mixed in?