One problem related to hydraulic power assist steering system has been reported for the 1999 Mercury Grand Marquis. The most recently reported issues are listed below.
At time when driving at highway speed steering power assist worked intermittently, causing poor vehicle steering control/ steering become very difficult, resulting in vehicle pulling to either left or right . Consumer has contacted dealer. Dealer has disconnected the speed sensor which corrected the problem.
| Steering Tie Rod Assembly problems | |
| Steering Wheel problems | |
| Steering problems | |
| Steering Is Tight problems | |
| Steering Linkages problems | |
| Hydraulic Power Assist Steering System problems | |
| Steering Gear Box problems | |
| Steering Idler Arm problems |