How are Variable Valve Timing Actuator issues diagnosed?
The variable valve timing actuator noise on startup will be clearly audible from the valve cover. If the actuator is suspected of failure, but the noise from the actuator is not clearly distinguished as a variable valve timing actuator, manufacturer specific testing may be used, or exploration may be required to diagnose the issue.

How are Variable Valve Timing Actuators replaced?
Since these actuators are part of the camshaft timing sprockets, the engine valve covers, engine front cover, timing components, and camshaft sprocket/variable valve timing assembly must all be removed to complete this repair. In many cases, the camshafts must be removed, as well as a camshaft timing chain. Any other components that prevent the removal of these components must be removed as well, and the engine must be properly timed before reassembly. Finally, once installed, the engine will be ran and tested for proper operation free from clatter.
RepairPal Recommendations for Variable Valve Timing Actuator issues
We do not recommend the use of thick oil to quiet the actuator. The oil specified for use by the manufacturer, both type and weight, should be used, and if the clatter exists, the proper solution is repair.
What to look out for when dealing with Variable Valve Timing Actuator issues
The noise made by these actuators are responsible for many engines being replaced, and many timing chain tensioners as well. It is especially important that when the variable valve timing actuator fails, the vehicle should be inspected by a qualified professional prior to replacing parts.
Can I replace the Variable Valve Timing Actuator myself?
Since this requires significant deconstruction of the engine bay, removal and replacement of timing components, removal of precision machined rotating assemblies, and extensive knowledge for performing these operations, this should only be left the a professional technician. There is a great margin of error in these repairs, and it is not worth the risk for the average or slightly experienced DIY to attempt.