One problem related to radiator hose has been reported for the 2004 Volkswagen Passat. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Volkswagen Passat based on all problems reported for the 2004 Passat.
On 12/28/2007 the oil cooler on my 2004 Passat failed and allowed large quantities of oil to leak into the coolant. The oil cooler repair was covered under vw's powertrain warranty. Per the Passat owner's manual and per verbal confirmation from vw, when a part covered under warranty fails and causes damage to other parts, those other parts are covered under warranty as well. In this case the dealer, flow Volkswagen of greensboro, nc, replaced not only the oil cooler but also the coolant reservoir, and flushed the cooling system 3 times. During the service they telephoned me at work and gave me a quote of nearly $300 to replace the thermostat because they felt it could have been damaged by the fouled coolant. At that time I was not aware that the thermostat was covered under warranty, nor did I know that the dealer already had the thermostat completely out of the vehicle. The dealers service technician noted that the coolant was the consistency of mud. The $300 quote that the flow Volkswagen dealer gave me involved a double charge on the labor as well as violated vw's warranty policy that the thermostat should have been covered. The dealer was already going to charge vw for the removal of the thermostat and other cooling system components, yet they were calling to ask me to pay for the labor as well as for the warranty covered part itself (the thermostat) that was damaged by the oil cooler's leak. During the phone call when I was given the quote the flow Volkswagen service personnel told me that the thermostat might be okay since they were cleaning it. In August of 2008, the Passat's check engine light came on. According to flow Volkswagen this time, the thermostat needed to be replaced and the total charge would be $478.