One problem related to timing tensioner has been reported for the 2007 Chevrolet HHR. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Chevrolet HHR based on all problems reported for the 2007 HHR.
Defective timing chain tensioner caused chain to jump time and cause valve damage costing $2000 in repairs. Apparently tensioner was known defect but never recalled.