The engine bay of a car is very often overlooked when it comes to cleaning as it may be considered a ‘non essential’ and the fact that the vast majority of the time nobody can see under the bonnet or hood means that often little attention is payed to it compared with other areas. Cleaning your engine bay and keeping it clean should be considered though, for a number of important reasons. Your car's engine contains a number of components that can become extremely dirty, very quickly due to the location of these parts and the nature of the things they do.
Keeping your engine bay clean ensures that excess grease, oil and dirt is unable to build up and accumulate in and around important or sensitive parts. Components critical to the operation of your car will perform better and be more reliable if kept clean and maintained.
Like washing your car car, cleaning the engine helps you to ‘get to know it’ and that means that you can catch any potential problems earlier on before they have the chance to develop into something more serious. For example whilst cleaning your engine you will become aware of any loose plugs or connections, corroded contacts, worn or perished piping or fluid/oil leaks. All of these things can potentially lead to more serious and costly problems later on in your cars life if neglected and allowed to develop.
There is also the important factor of resale value. Keeping your engine clean will almost certainly help with the resale value of your car and will be viewed by potential purchasers in good light, especially if other similar cars that have been viewed had dirty and neglected looking engine bays. A clean engine bay suggests that the rest of the vehicle has also been properly maintained and treated with care during its lifetime.
Once your engine has had a thorough clean it should not need properly cleaning again for a good period of time. When regularly washing your vehicle you should dry off any excess water from the shuts and similar areas under the bonnet/hood and give the main surfaces a general wipe over to keep it appearing fresh and well maintained. A good idea of when to give your engine bay a thorough clean would usually be to do so when your car has just been serviced.
The most important thing to consider when cleaning your engine is that any important or sensitive components are covered with a suitable material to avoid any water penetration. This would include parts such as the alternator, fuse box, battery terminals, air intake, and any electrical plugs & connections. A shrink wrap or cling film type product is a good choice to use as it is thin, transparent and can be worked around awkward areas fairly easily to provide a water tight seal.
The main product required for cleaning would be either a designated engine cleaner/degreaser, or a diluted all purpose cleaner which can be used to clean all areas. Soft bristled detailing brushes should be used to work cleaning products into hard to reach areas and ensure dirt, grease and oil is effectively lifted from surfaces.
For rinsing off your engine you can either use a pressure washer but be sure to use it on a light pressure setting if possible, or a hosepipe with a suitable light sprinkle nozzle can be used. In either instance even through sensitive parts should have been covered it’s very important to ensure you don’t excessively over wet the engine compartment, or drive water into and around these sensitive areas.
Micro fibre towels should be used to effectively dry off all parts the engine bay as much as possible after cleaning. Micro fibre or sponge applicator pads can be used to apply dressing/protectant products to plastic/rubber components and to also apply either a normal paintwork polish or a designated chrome/metal polish to applicable parts if necessary. Fine wire wool may be required when polishing metal details to help remove any oxidation or ingrained dirt and again micro fibre towels should be used to remove any polish residues.