How to Get Your Engine Bay Clean Enough to Eat Off, and Why You Should

To most car owners, having a dirty engine bay might not seem like a big deal. It isn’t a place in the vehicle that you often see, such as the outside or interior of the cabin, so it’s easy to ignore. The engine bay doesn’t need to be washed as often as the rest of the car or detailed as often as the interior cabin space, but it is a good practice to check on under your hood and clean once in a while, just as general maintenance. Keeping an engine bay clean can help in case of diagnostics, such as when you suspect you are leaking oil or other fluids, and it can also help prevent corrosion and other potential problems.

Engine bay of a 1990 BMW 325i Sport
The engine bay of a 1990 BMW 325i Sport | National Motor Museum, Heritage Images, Getty Images

Quick and easy tips for cleaning your engine bay

Engine bay of a 1987 Peugeot 205 GTI 1.6
The engine bay of a 1987 Peugeot 205 GTI 1.6 | National Motor Museum, Heritage Images, Getty Images

Cleaning your engine bay isn’t all that dissimilar from washing your car — except you don’t have to be worried about damaging or swirling your paint. Using a spray bottle (which you can usually find at a dollar store or for a few dollars at most grocery stores in the cleaning section) and some soapy water — I would recommend dish soap as it is meant to be used on greasy, oily surfaces — mist the engine bay and let it sit for a few minutes. You can use a brush or a rag to agitate the dirt, grime, and grease after a few minutes, and if your engine compartment is extraordinarily dirty, you can use a degreaser spray which can be purchased at your local auto shop. Rinse thoroughly with a hose or gently with a pressure washer, and repeat until clean.

Why should you clean your engine bay?

Engine bay of a 1991 Jaguar XJS V12
The engine bay of a 1991 Jaguar XJS V12 | National Motor Museum. Heritage Images, Getty Images

In an engine bay with a gasoline-powered engine, things can get pretty grimy. There are a lot of moving components that require fluids and lubrication, which can leak out into the engine bay and create quite a mess over time. Besides that, your engine bay isn’t completely closed off from road debris and other hazards, meaning it can collect dirt, leaves, and dust that leave your engine and other components caked in a thick layer of gunk. Keeping your engine bay clean is an underrated part of vehicle maintenance that protects the engine compartment and its occupants from corrosion and damage and can be useful if your vehicle is in need of diagnostics for a suspected problem — such as an oil or coolant leak.

Cautions and warnings to keep in mind while cleaning

While most of the components of your vehicle’s engine bay are heavy-duty, older cars can fall victim to plastic and rubber rot in hoses and clamps, making them fragile and prone to breaking. It is important to take this time to assess if there are any damaged or cracked components inside of the engine bay prior to cleaning to ensure you don’t get water into a place where it isn’t supposed to be. It is also important that you completely rinse off any soaps or degreasers that were used in the cleaning process, both off of your engine compartment and your car. Because degreasers are abrasive and strip oils, grease, and wax, it is important to remove any of this product from your vehicle’s external panels and reapply wax to protect the paint. Other things to keep in mind:

  • If you’ve driven your vehicle recently, make sure that the engine has cooled down completely before you start to clean.
  • Don’t wash your engine bay on a freezing day. Stick to warm days when the water can evaporate from the engine compartment.
  • Leave the hood open to help your engine compartment dry thuroughly.

The Best Method for Cleaning Your Engine is a Little Nuts