The OP says one side is extremely hot and the other side is extremely cold. That's one hell of a radiator if it can keep one side hot and the other side cold. Degrees of difference side to side yes but not as the OP describes "extreme".
It does sound to me like the radiator may be clogged but why the car does not overheat I cannot understand.
Originally Posted by thomastl
That is what it is supposed to do. If the engine is not overheating - it is working.
Hot comes in from the engine on top Driver side. Exits to engine on lower passenger side.