Shaking and shuttering and loss of power.

My car will start just fine and if I drive right away will most like drive ok for a while but if I start it and sit for a little then drive it starts to idle funny it jerks and vibrates hard and sounds as tho it might stall and rarely does. Then if I move it will almost redline before shifting into the next gear and it only seems to run at partial power. It jerks but the jerking gets faster as there's more acceleration. The check engine light is always on and when it acts up the ligh blinks. As you drive the temp goes up almost to 190 then goes back down and then back up. Usually once it finally hits 190 then the check engine light stops blinking but stays lit and the car runs fine. I've had it to a mechnic and they couldn't find it. He said to go to the dealer. I took it there and they said my spark plugs and wires were bad. So they fixed them and gave it back. But that did not fix the problem. I've checked the thermostat and it seems to be working. I replaced the oil and fuel filters and the air filter is fine. I'm racking my brain here no one can find the problem both the dealer and the mechanic said there's no codes so idk what to do! E