A car's engine bay tends to get dirty fairly quickly and easily. It's a good idea to clean it every once in a while. How do you do that properly?

I have a 2005 VZ Commodore SV6 with sludge build up in the engine. It has caused a lifter to stick. What is the best way to flush/clean the engine? If you have been servicing your car regularly, ...

This should sufficiently and safely clean your engine while protecting against further sludge buildup. Over the next couple of drain intervals with a good oil product, your engine should be cleaner.