One problem related to radiator has been reported for the 2009 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Toyota Sienna based on all problems reported for the 2009 Sienna.
2009 Toyota Sienna. Consumer writes in regards to engine overheating. The consumer stated he replaced the fan relay and thermostat. However, the vehicle continued to overheat. The dealer replaced the radiator and water pump, but the overheating continued. The dealer informed the consumer they looked into the cylinders with a borescope and saw marks on the cylinder wall which lead them to the conclusion that the head gaskets were bad and they would have to be removed and sent to a machine shop to see if they were warped and the cylinders and engine block would have to be inspected to see if there was an issue.