One problem related to engine belts and pulleys has been reported for the 2004 Mercury Mountaineer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Mercury Mountaineer based on all problems reported for the 2004 Mountaineer.
2004 Mercury Mountaineer - harmonic balancer failed. It was noticed when a squeaky noise was coming from the engine. Although is was caught before any serious injury occurred, this failure may have led to one. If the balancer had completely failed, it could have resulted in loss of steering and at highway speeds would have been catastrophic. Steering is lost because drive belt would have come lose. Unit was replaced at a cost of $475. Old part was saved for inspection.