Heater Core Replacement & Radiator Flush on 2002 Volkswagen Passat

No heat for months. Heater core flushed with little improvement. Recommended (by our own mechanic)we replace heater core. VW Dealer also says we need new radiator and my wife settles for $87 radiator flush instead with the core replacement. Shouldn't radiator flush come standard with heater core replacement? Did VW just tack on another charge? (We used a $250 coupon they offered - 3% times the age of the car). I just think they're recovering that money.

Asked by for the 2002 Volkswagen Passat
They don't even need to drain the radiator to replace the heater core. The hoses can be clamped and most of the coolant stays in the system. The flash takes extra time and new coolant, that's why the extra cost.