First, I need to know the model of the vehicle. The Dynasty was discontinued in 1993.
Now, without knowing the exact vehicle, I need to know was the engine block flushed? Does it run properly before overheating? Have you ever noticed any air bubbles in the engine coolant, has the coolant been dropping in level or anything out of the ordinary?
Take a look through this link It explains how to check for a head gasket. Keep in mind, there doesn't have to be white smoke or coolant mixing for there to be a head gasket issue. Try this. When the engine is cold, remove the radiator cap and start the engine. Does the coolant start coming out? There could be compressed air entering the cooling system from a cylinder or cylinders which can cause issues. So check that.
One other thing, are you certain it is actually overheating? There could even be an issue with the coolant temperature sensor.
Let me know. Here is the link I mentioned above. Let me know if it helps.
Let me know what you find or if you have other questions. Also, if the check engine light is staying on when the engine is running, let me know that as well. If it is, let me know if you had it scanned and what codes were retrieved.
Monday, March 9th, 2020 AT 7:07 PM