Here’s How I Degrease My Filthy Engine Bay Without Damaging Anything

Protect the electronics, and don't be shy with the degreaser.

I am not someone who’s reveled in cleanliness with my cars. Besides the interior, I really couldn’t be bothered to drive through a car wash more than twice a year, let alone do a big detail. I let old oil residue hang around my engine bay until I have to remove and clean the part. I commuted too much, did too many miles to care. But now that my beloved GTI mostly sits at home and gets used for fun stuff, I’ve started feeling really bad about its shabbiness. In the name of de-shitboxing my car, I finally decided to clean something I’ve been neglecting for a year and a half: my engine bay.

Car Bibles has a step-by-step informational post on engine-bay cleaning you can also check out, but knowledge is power so you might learn something else from my methods and experience specifically.

Here’s How I Degrease My Filthy Engine Bay Without Damaging Anything
Image: Chris Rosales

I did some YouTube research and watched some short videos just to make sure I wasn’t missing out on any special techniques, but the general principle is always the same. I ventured out to my local auto parts store and picked up some degreaser specifically this CRC Heavy-Duty Pro Strength stuff, which I paid for myself. I already had some plastic bags and an old toothbrush at home so I returned and promptly popped my hood.

I started with taking my plastic bags and covering my alternator and my intake. My battery already had a useful cover on it so I didn’t need to worry about it, and no other sensitive electronics were exposed. Mileage may vary for your car, but, cover the big electrical stuff! The normal connectors are generally pretty waterproof so don’t pay too much worry to them.

You’re going to want to wait until your engine is cool to clean it in general, the prospect of these bags melting should not be a concern.

Here’s How I Degrease My Filthy Engine Bay Without Damaging Anything
Much protection. – Images: Chris Rosales

Once you’re all set up and covered with your high-tech “Thank You, Come Again” plastic bags, grab your degreaser and read the label for how to use it. Once you get that, start spraying! This particular degreaser was of the foaming type, and all you had to do was spray as heavy as necessary. Let it sit for about five minutes for maximum effect. Grab your preferred brush (mine was an old toothbrush) and start scrubbing any particularly built-up areas to unstick stubborn oil or dirt. 

Here’s How I Degrease My Filthy Engine Bay Without Damaging Anything
Image: Chris Rosales

Once you work your way around the engine bay with your toothbrush, grab a garden water hose with some water supply. Turn the water on a medium-flow, use your thumb to make some pressure, and start rinsing all of the degreased areas off. Unless of course you’re real fancy and have a nozzle with a trigger. Look at you, moneybags!

You won’t hurt any electrical connectors with the low-pressure water unless you really sit there and spray a connector for a minute straight at point-blank. Give the entire bay a good rinse, stand back and let it dry. I have an air compressor so I used some pressurized air to get pooled-up water out of crevices, but you don’t need to do that.

I was honest-to-goodness shocked at the result of my first pass. It damn near cleaned my filthy oil-soaked engine in one go. There were still a few spots of particularly stuck oil and other parts of my engine bay started looking super shabby. Consequently, I broke my degreaser out again and sprayed even heavier, and started going detail crazy. I even started spraying down in the crevices of the engine bay where I saw some dirt and even the lower timing cover because I suddenly became offended by the dirt. I was emboldened by the efficacy of the degreaser as a new and deadly tool in my war on oil here.

Rinse and repeat until your engine is squeaky clean! The one lesson I did take away from this: don’t be shy with how much degreaser you spray on. Pile it on! Also, really work at that brushing. 

Here’s How I Degrease My Filthy Engine Bay Without Damaging Anything
Image: Chris Rosales

I took another three full passes with the degreaser to get my engine bay looking like new. That is not an exaggeration, this shit looks new! I was trying to get other work done on my car but I kept getting distracted by the matte glimmer of my clean valve cover and engine bay plastics and the white paint that has been revealed under many layers of filth.

Go out and clean your engine. It was super easy and took me 30 minutes total, and out all of the mods I’ve done on my car, just cleaning it and giving it some love was one of the most gratifying things I’ve ever done to my venerable old hatchback. Show us your results in the comments!

Chris Rosales

Chris RosalesChris has owned 12 cars of questionable quality, is an experienced motorsports photographer, and a good all-around wrench. When he isn’t tinkering with his car in his home garage, you can catch Chris in the canyons around SoCal. He also hopelessly hankers for Euros, but he honestly knows he should get something Japanese, eventually. Contact the author here.