Steering & Suspension
If knocking or clunking is heard from the front of the Jaguar XJ when being driven over bumps or pot holes, it’s likely to be a problem with the front suspension, in particular, a worn lower front suspension arm.
These suspension arms are exposed to significant levels of stress, especially when being driven hard or over uneven or badly damaged road surfaces, which is why the bushes in the arm are prone to wear. If this is found to be the case, the best solution is to replace the complete suspension arm, including the bushes.
As with all steering and suspension components, FLG recommend technicians best practice is to replace the matching components on both sides of the vehicle at the same time as generally if the one side has suffered wear, then the opposite side will also have been subject to similar damage. Even though this may not be evident at the time, it is likely to need replacing soon after and irrespective, when one component is worn and its opposite is new, it can have an adverse effect of the opposite component, as well as the handling characteristics of the vehicle, which is why best practice is to change both together.
When doing any servicing or repair work on the Jaguar XJ it is important to check the condition of the thermostat and it’s housing as well as the hoses which run underneath the intake manifold as these are prone to leaks. When any cooling work has been completed ensure the cooling system is bled correctly and take care to tighten the bleed screw to the correct torque of 3Nm.
The braking system can suffer from the front brakes creaking under light/medium braking. If this occurs, the front brake caliper carrier should be cleaned and lubricated, new brake pads should be fitted and the brake pad backing plate contact points greased.
The air filter should be replaced every 40,000 miles or 48 months, whichever comes sooner. A clogged/dirty air filter can lead to impeded performance and increased fuel consumption.