One problem related to engine cooling system has been reported for the 2006 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota 4Runner based on all problems reported for the 2006 4Runner.
2006 4runner sport edition 4wd -Toyota- 38k miles on vehicle. All the bolts that hold the clutch assembly to the a/c compressor is rusting out to the point that the compressor will come apart during driving and damage other components and probable cause accident. This was notice at ~24k and it's getting worst. Presently, all the bolts head is almost gone and apart from the rusting bolts there is a second part on the clutch assemble that is also rusting. Toyota will not accept it under there warranty.