One problem related to coolant leaking has been reported for the 2003 Mitsubishi Montero Sport. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mitsubishi Montero Sport based on all problems reported for the 2003 Montero Sport.
Head gasket failures on 2003 Mitsubishi Montero Sport 3. 5 l v6 engine. 1. No preceding event, car started idling rough when first started. Idle smoothes after a short time. 2. Right side head gasket started leaking coolant into cyl #2 at 30k miles, replaced under warranty. Left side head gasket started leaking coolant into cyl #1 at 65,600 miles. Replacement denied by manufacturer, even thought it is an obvious manufacturing defect. 3. Not yet replaced due to cost.