One problem related to hydraulic power assist steering system has been reported for the 1998 Jaguar XJ8. The most recently reported issues are listed below.
Engine stalls at highway speeds with no advance warning. Power steering and power brakes are therefore also inoperable. Vehicle must be coasted in this condition to a stop and put in "park" before it will restart. This obviously is a life-threatening maneuver in multiple lanes of 70 mph traffic. Dealer has attempted several times to repair vehicle. Condition has occured multiple times; the date below is the most recent.