One problem related to engine cooling system has been reported for the 2003 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Toyota 4Runner based on all problems reported for the 2003 4Runner.
Model : 2003 Toyota 4 runner v8 issue : automatic acceleration while a/c on how to duplicate the issue : option 1] while the engine is running and the vehicle is in drive with brakes depressed turn the a/c "on", the vehicle would try to suddenly move forward. The tachometer also shows higher readings. Option 2] turn your a/c off drive for a while and then turn your a/c on, the moment you turn your a/c on the vehicle accelerates on its own for a while. This problem is magnified especially in summer and hotter climates and does not fail to occur in summer.