One problem related to engine knocking noise has been reported for the 2011 Hyundai Tucson. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Hyundai Tucson based on all problems reported for the 2011 Tucson.
Engine has a very bad knocking sound as described in recalled cars that catch fire with the same engine. I can't drive it in this condition and the mechanic says repair is very expensive and might not fix the problem. There is a concern that there are no good engine parts from which to ever fix it. The sound just keeps getting worse.