Seal used on the Radiator.
PACKING-RADIATOR UPPER Radiator Air Seal
Fits WRX
Radiator
Typical symptoms for a failed radiator include both an overheating engine and a coolant leak. But some radiator failures can also result in burned or dark transmission fluid. If the cooling system in your 2017 Subaru STI needs attention, contact a factory-trained Subaru technician.