How To Detail Your Engine Bay

Engine bay detailing refers to the process of removing perhaps thousands of miles’ worth of dust, dirt and grime from the space inside your car where the engine is held.

Although this may seem like a daunting or delicate process, it’s possible to do yourself with a little planning, thought and effort. The result is a clean, beautiful engine bay that looks just like new—as well as a vehicle that functions more reliably and has a higher resale value.

People often miss the importance of cleaning the engine bay of their cars, in part because it’s not the first thing you see when you look at a vehicle. In fact, most people never see it at all—so undoubtedly there are plenty of beautifully cleaned, polished and waxed cars on the road that are hiding terribly grimy engine bays. However, the engine bay gets dirty really fast.

Cleaning it makes sure that grease and dirt don’t accumulate within or surrounding components that are essential to the function of your car. Dirt tends to cause degradation of components over time—the pulleys and bearings especially are damaged by grit and grease accumulation.

The other benefit of cleaning your engine bay is that it allows you to get a better understanding of what’s there and keep an eye on any problems that may arise over time, which dirt and grime can hide. If you catch any leaks, corrosion, etc. early, you might be able to save lots of money by preventing worsening issues later on.

Additionally, a clean engine bay helps maintain your vehicle’s resale value, as it is indicative of a well-maintained automobile overall.

Note: Although this process is generally quite straightforward, you will definitely want to take extra precautions if your car is from the 1990s or any older. The particular concern is that although most of the time, electrical components are protected if they’re hit with a high-pressure flow of water it can get inside and cause problems.

So it’s a good idea to cover parts like your car’s alternator, fuse box, air intake, electrical connections/plugs, and battery terminals—plastic shrink wrap/cling film is a great choice for this kind of protection.

Note that this is not an exhaustive list of precautions you should take when detailing your engine bay. And when in doubt, ALWAYS seek the guidance of a professional for your own safety and that of your beloved vehicle!

Ready to get started?

Here’s our list of 10 straightforward steps to keeping your engine bay spotless and beautiful:

1. Gather your materials

These will include, but are not necessarily limited to:

  • Engine degreaser

  • Water hose

  • Plastic bags/plastic shrink wrap

  • Bucket

  • Drip pan

  • Car wash mitt

  • Wash brush

  • Car wash soap

  • Absorbent pads

  • Terry and microfiber cloth towels

  • Plastic cleaner

  • Metal cleaner/polish

2. Give the engine bay an initial hose-down

This is an important step just to get rid of a lot of the dirt that’s on there and help the degreaser spread further.

Be sure to do this once the engine is cool—it doesn’t have to be entirely cold, but you should leave the hood up for at least an hour before you start the process.

While you’re waiting, put down some drip pans and absorbent pads so that the chemicals you’re using don’t get everywhere.

3. Protect parts from water

Cover the battery with plastic (a bag or shrink wrap). You may also want to cover the alternator, carburetor, and distributor. This will depend on what kind of car you have—whether it’s a classic or modern car, for one.

Make sure you don’t spray too much water around the fuse box and coil packs if you’ve got a modern car.

4. Add the degreaser

You’ll want to use degreaser rather than standard soap because it cuts through the oil (hence the name “degreaser”).

Apply liberally in the oiliest areas such as the oil pan and starter. Typically you will want to allow the degreaser to sit for several minutes so that it acts on the grease effectively.

A wash brush will also help get things clean, and the soft bristles won’t create any worrisome scratches.

5. Rinse again and perhaps repeat

Using low water pressure, give it all another rinse. If your engine bay hasn’t been detailed in a very long time, you may have to repeat step 4.

6. Clean again with automotive soap

Fill the bucket with soapy water and, using your car wash mitt, get everything really clean now that the degreaser has removed the worst of the oil.

7. Rinse again

Once again, use low pressure to rinse everything. Then remove the plastic bags or cling wrap from the components you were protecting, since there won’t be any more big splashes of water.

8. Polish plastic and metal parts

Polish plastic parts with plastic cleaner, applying the cleaner with your terry cloths and then removing it with the microfiber cloth. This will help to remove small scratches. And then use metal polish as the particular product’s instructions describe (they may all be different).