How to Clean Your Car's Engine Bay

In this article, we will walk you thru the steps in cleaning your car's engine and engine bay. The process of cleaning the engine bay is divided into 5 main procedures.

Cleaning and detailing your car's engine bay is a tedious task, but it is gratifying; if you decide to clean and detail your car's engine bay, we have prepared a series of instructions for you.

What you will need:

  1. Microfiber towels
  2. Brushes with plastic bristles in different sizes
  3. Paintbrush of different sizes.
  4. Cleaning wipes
  5. Spray wax
  6. Trim restore
  7. Soapy water
  8. A pair of globes
  9. A pair of safety glasses
  10. Dust mask
  11. Electric metal brush
  12. Vacuum cleaner
  13. Leaf blower
  14. Air compressor with small diameter nozzle
  15. Garden hose
  16. Water supply
  17. Plastic garbage bag
  18. Carpet cleaner solution
  19. Flat-head screwdriver
  20. Paint markers in black, white, or light colors.


First would be the preparation; this process will ensure water-sensitive components such as sensors, distributors, coils, and sparkplugs are safe.  

The second is the dry cleaning process; dirt and dust are removed by the brush or air tool in this process.

The third process is wet cleaning; in this process, the engine bay is spray cleaned with water, while the engine is only sprayed with soap with water.

The fourth process is the Drying of components; in this process, the engine and the engine bay are dried.

The last step is to detail the engine and the engine bay; in this step, the engine and the engine bay are buffed shine.

Cleaning the hood is accomplished by doing the following:

  1. Preparation 
    • Let the engine cool down.
    • Remove the battery to avoid shorting out any connection while being saturated with water and soap.
    • Avoid soaking the alternator, distributor, and spark plug's end wires.
    • Do Not use pressurized water to clean the engine bay; this may result in water penetrating various engine sensors and shorting them out or cause corrosion on the terminals.
    • Be sure that the engine dipstick is tucked in properly to avoid water contamination with oil.
    • Tighten any fluid reservoir such as brake, clutch, power steering, and transmission (if automatic).
  2. Dry Cleaning
    • Wear your dust mask and safety glasses.
    • Remove the dust from the engine and engine bay using the appropriate paintbrush in tandem with a vacuum cleaner.
    • Brush off any dust on reachable parts of the engine and engine bay.
    • Connect the small nozzle to the air compressor and use the nozzle to brush areas unreachable to the brush or vacuum nozzle. If an air compressor is not available, use a leaf blower instead.
    • Clean the aluminum part of the engine with a metal brush or electric metal brush. Be extra careful when using the brush near sensors and rubber hoses.
    • Don't forget to get rid of the dust particles on the inside of the hood.
  3. Wet cleaning - In this process, the engine bay is spray-cleaned with water, while the engine is only sprayed with soap with water. Wet cleaning can be divided into 3 parts: cleaning the hood, cleaning the engine bay, and cleaning the engine.


    • Cover the engine with a plastic garbage bag to avoid the engine being soaked with water once the cleaning of the hood has started.
    • Start cleaning the back of the hood by hosing the painted side of the hood.
    • If the hood liner still looks good and solid, spray it with water to clean it up. But if the hood liner is sagging or looks damaged, do not spray water on it, for it may get more damaged.
    • Spray the entire back of the hood, including the hood liner (if the hood liner is good), with soapy water.
    • Use a microfiber towel to dry and remove remaining blemishes from the hood and hood liner.
    • If the hood liner still looks dirty after the above procedure, spray carpet cleaner on the hood liner.
    • Rinse the entire back of the hood with water from the garden hose.
    • Spray the left side of the engine bay with water to wash out the dirt.
    • Loosen the dirt from the left side of the engine bay with a cleaning wipe.
    • Rinse the left side again with water.
    • Soak each side of the engine bay with soapy water.
    • Use a paintbrush to further loosen the dirt from this side of the engine bay.
    • Rinse again with water from the hose.
    • Remove the plastic bag off the engine.
    • Clean off the oil from parts of the engine using a cleaning wipe.
    • Spray the area with soapy water and use a brush to clean off the dirt and oil.
    • Use a long plastic bristle brush to reach hard-to-reach areas of the engine.
    • Spray the wiring harnesses with soapy water and loosen the dirt using a plastic bristle brush.
    • Use a microfiber towel to remove the soap and dirt from the engine.
    • For hard-to-reach areas, wrap the long plastic bristle brush with a microfiber towel and insert it into the hard-to-reach areas to remove the wet dirt, oil, and soap.
  4. Drying of components - In this process, the engine and the engine bay are dried.
    • Using a microfiber towel, get rid of the water from the engine and the engine bay.
    • Dry off any remaining water from the engine bay and using a microfiber towel or a wet and dry vacuum cleaner.
    • Clean off missed spots by using soapy water and a microfiber towel.
  5. Detailing -In this step, the engine and the engine bay are buffed shine for presentation.
    • Remove the hood liner by prying off the retaining clips using a flat screwdriver. 
    • Use a dye to restore the color of the hood liner. Wait for the dye to dry.
    • Spray the entire painted part of the back of the hood with spray wax; this will give the hood a decent shine.
    • Buff the wax using a microfiber towel.
    • Spray the wax on all painted areas of the engine bay and buff with a microfiber towel.
    • Use a trim restore and a brush on all plastic and rubber parts of the engine and the engine bay, including the hoses and high tension wires. Avoid contaminating the serpentine belts with the trim restore.
    • Let the trim restore sit on the surfaces for 5 minutes, then shine off the surfaces using a microfiber towel.
    • Look for rusted metal parts, then loosen the rust using a wire brush, then paint the part with a black paint marker.
    • Look for a raised and faded lettering on reservoirs, then use a white or light color paint marker to highlight the raised letters.
    • Re-install the hood liner.
    • Re-install the battery.

Frequently Asked Questions

How often should an engine be cleaned of debris?

  • Typically, if you live in a city or other urban area with little to no debris on the roads, you should try to clean your car engine at least twice a year. If you reside in a dry area where large amounts of dust can accumulate in your engine bay, you should clean your engine approximately every three months.

Can I pour cold water on my engine to cool it down faster?

  • Never pour cold water into a still-hot engine. It could cause the engine block to crack due to the sudden temperature change. 

How much does an engine detail cost?

  • It takes me about an hour and a half to do a basic engine, engine bay, cleanup, and detail, average from $75.00 to $100.00. A car with a rear-mounted engine, like a 360 or 430 Ferrari, double or triple the time and price.