why does my 98' cadillac catera keeps on stalling?

[bige626]

Recently my 1998 cadillac catera's temp gauge has been falling into the red area as well as the oil gauge. I thought it was just because of the hot weather. Then one day when I was driving, and I was at a stop light, the car just stalled on me. prior to stalling on me, both the temp and oil gauge would come on and I wouldnt be able to accelerate. It would usually take me 10 or 15 tries to crank the car back up after I turn the car off then on again, but after I think everything is ok, and I drive away, it would stall on me again. I took it to pep boys and they said their machine couldnt find anything wrong with the car. I drove it today and only the temp gauge went into the red area. but the car did not stall. I dont know what I should do. I even tried adding 10w-30 oil because the oil was actually low, but it didnt help my stalling problem. I need sum help please