2007 Mack Chn Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2007 Mack Chn, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Engine1100.0%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
2007 MACK TRUCK CHN 613, 427 ASET AC ENGINE FAILURE DUE TO OIL PUMP DRIVE GEAR SPINNING LOOSE ON AUXILIARY SHAFT. WHEN THE VEHICLE BEGAN TRAVELING DOWN HILL, THE OIL PUMP DRIVE GEAR FAILED CAUSING AN IMMEDIATE LOSS OF OIL PRESSURE. THE ENGINE BECAME A CRITICAL INSTRUMENT IN CONTROLLING THE VEHICLE'S DOWN HILL SPEED PARTICULARLY THE ENGINE BRAKE FEATURE AKA THE "JAKE BRAKE". THE ENGINE BRAKE USES ENGINE OIL FLOW TO OPERATE. SINCE THERE WAS NO MORE OIL FLOW, THE ENGINE BRAKE WAS RENDERED UNUSABLE. AT THIS POINT, THE CHOICE WAS TO CONTINUE DOWN HILL AND RELY SOLELY ON THE VEHICLE BRAKES TO CONTROL THE VEHICLE SPEED, OR CONTINUE TO USE THE ENGINE WITHOUT THE ADDED BRAKING POWER OF THE ENGINE BRAKE KNOWING THAT THE ENGINE WOULD BE DESTROYED. THE DRIVER CHOSE TO DESTROY THE ENGINE AND NOT RISK HIS LIFE OR THE LIVES OF OTHERS. THE DEALER REFUSED TO REPAIR THE VEHICLE UNDER WARRANTY BECAUSE THE EECM INDICATED THE ENGINE'S MAXIMUM ALLOWED SPEED WAS EXCEEDED. FURTHER INVESTIGATION REVEALED THE PROBLEM IS INHERENT TO ALL ASET ENGINES BECAUSE THE OIL PUMP GEAR HELIX WAS CHANGED FOR THE NEW DESIGN ENGINE. THE AUXILIARY SHAFT DIRECTION OF ROTATION WAS REVERSED AND THE DIRECTION OF THRUST ON THE DRIVE GEAR FORCES THE DRIVE GEAR AWAY FROM THE REAR BEARING JOURNAL WHICH IT IS NESTED AGAINST. OLDER ENGINE DESIGN HAD THE DIRECTION OF THRUST TOWARD THE BEARING JOURNAL WHICH HELD THE GEAR IN PLACE. ANY CONDITION, (LIKE AN ENGINE OVERSPEED) THAT WOULD INCREASE OIL PRESSURE COULD DISLODGE THE GEAR. ACCORDING TO THE DEALER, AN ENGINE OVERSPEED CONDITION CAN ONLY OCCUR WHILE GOING DOWN HILL AND USING THE ENGINE TO CONTROL VEHICLE SPEED. IF THE HILL WOULD HAVE BEEN HIGHER, THE ENGINE MAY NOT HAVE BEEN ABLE TO CONTINUE TO SLOW THE VEHICLE AND A CRASH WOULD MOST LIKELY HAVE OCCURRED. THIS HAPPENED IN SOUTHEAST LOUISIANA WHERE HIGH HILLS ARE NON EXISTENT. HAD THIS HAPPENED IN A MOUNTAINOUS AREA, IT COULD HAVE BEEN DISASTROUS. MACK TRUCKS REFUSES TO DISCUSS THIS ANY FURTHER. *TR
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .