What is the best thing to clean an engine with?

Thoroughly spray the entire engine compartment with degreaser. Any household degreaser will work, whether it's a kitchen cleaner or a purpose-made engine degreaser. We've used Simple Green (we like its eco-friendly formula). Don't hold back—every square inch should be covered.

Do engine cleaners actually work?

Yes! When used regularly, fuel system cleaners can help work to remove harmful deposits and keep new ones from forming. They are especially important for engines running on gasoline containing Ethanol and fuel-injected engines.