Two problems related to loud engine noise 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.
Whiled I was driving I went over a bump in the road. The fan on my truck started making a loud noise. I took the vehicle to a repair shop to be checked. This I when I found out that the frame on my 2005 Toyota Tacoma was cracked and caving in where the motor mounts attach to the frame. This caused the motor to drop down and the fan started hitting on the shroud. Also it pierced a hole in my upper oil pan when the motor dropped down and hit the rack and pinion. Upon research there are many many cases of this happening to the 2005 -2006 Tacoma trucks. This is clearly a safety issue that Toyota refuses to fix.
Around the end of April my Tacoma started making a horrible noise whenever I backed up. After some searching around I found my fan was rubbing on its cover. Next I looked into why on some forums, so after some research I discovered its do too a broken motor mount. I got under my truck and true to behold my motor mount had collapsed into the frame. This is a well known issue with 05-06 Tacoma's yet Toyota wont do anything. They say im 100,000 miles out of warranty. To make it worse Toyota is well aware of the matter because all 07 and newer Tacoma's have extra support plate welded on the frame to prevent collapse.