How do you troubleshoot a malfunctioning Nissan Navara engine?

I have been experiencing issues with my Nissan Navara's engine, it seems to be making strange noises and the performance has decreased. What steps can I take to diagnose and fix the problem?

First, check the engine oil and coolant levels. Low levels may indicate a leak or another issue that needs to be addressed.

Next, inspect the spark plugs and ignition coils. These can often be the culprit for engine problems and may need to be replaced.