Two problems related to radiator have been reported for the 2006 Toyota Tacoma. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota Tacoma based on all problems reported for the 2006 Tacoma.
Noticed a loud rubbing noise from the radiator fan hitting the shroud in reverse. Opened the hood to observe that entire engine was leaning to the drivers side. Noticed from under vehicle that the drivers side motor mount was collapsed into the frame by approximately 3/4 of an inch. Further observation indicated that the mount appeared to break at the weld and then tear the frame in front and behind of the welds for the motor mount. Looked on-line for similar occurrences and discovered that many owners of this vehicle have the same problem without any resolution from the manufacturer (Toyota). Others on similar sites observed that between the 2006 model year (mine) and 2007 model years Toyota added a reinforcement to the motor mount indicating that they knew of a problem but were not willing to alert owners to the problem. I have pictures of my broken frame and a 2007 and later model frame to show where the engine mounts were reinforced.
The frame at the rf motor mount broke and the engine dropped so that the fan is hitting the shroud of the radiator, there seems to be a weakness in the weld location that the manufacturer changed on the 2007 frame in this location of the motor mount area. The dealer/manufacturer Toyota is not warranting this defect , there are a lot of complaints on the internet, I hope they also filed with the NHTSA.