The engine oil pan gasket can develop a leak. Leaking oil may accumulate on the exhaust system resulting in a burning smell. Replacing the gasket should correct this leak.
2005 Jaguar X-Type Problem Reports
Most Reported 2005 Jaguar X-Type Problem Reports
The plastic coolant reservoir is prone to leak. The reservoir can mysteriously lose coolant or coolant may pool under the engine compartment. If this occurs, the coolant reservoir should be inspected for cracks. If leaks are neglected, the reservoir may fail and cause the engine to overheat.
front axle dislodged from transfer case...mechanic still has car. Mechanic has stated that he has seen this happen a few times on this model