How to Clean a Car Engine Bay?

[MacNorah]

Open the hood, cover the distributor, battery, and brake fluid reservoir with plastic sheets, then rinse the engine with a water gun. Rinse the air intake vents and remove dirt from the engine bay insulation. Use a flannel cloth dipped in water to clean the radiator, cooling fins, and condenser. Carefully wash the engine bay support bars with a water gun, and use an air gun to blow away dust particles inside the bay. Remove the plastic sheets and thoroughly dry all parts of the engine bay with a towel or flannel cloth.

[SanChristopher]

I just cleaned my engine bay by myself a couple of days ago, sharing some tips: First, wait until the engine cools down completely, otherwise pouring cold water on it could warp the cylinder block. Cover water-sensitive areas like the battery and fuse box with plastic bags, then use a low-pressure spray nozzle set to mist mode, keeping about 30 cm away to rinse off surface dust. Spray specialized cleaning foam on oily spots, wait five minutes, and gently scrub with a soft brush—be extra careful not to spray directly near the alternator or ECU. After rinsing, use compressed air to blow out water from crevices, then apply a layer of wiring protector to prevent rubber parts from aging. Finally, start the engine to evaporate remaining moisture. The whole process avoids high-pressure washers, with emphasis on meticulous protection.

[Emmanuel]

Cleaning the engine bay requires strategy. I always start by disconnecting the negative battery terminal to prevent electrical faults from water ingress. Cover the intake pipe and sensor ports with thick cloth to block moisture from entering cylinders. Use pH-neutral cleaners as strong alkalinity corrodes metal parts. After spraying cleaner, wait for stubborn grease to dissolve before detailing wiring harness corners with brushes. Rinse using unidirectional water flow from top to bottom to avoid dirty water backflow into spark plug holes. Blot wiring surfaces with super-absorbent microfiber cloths after rinsing, and use compressed air for radiator fin gaps. The entire process prioritizes waterproofing electrical components.

[SanGeorge]

When I wash my car, I also clean the engine compartment: After the engine cools down, I remove obvious leaves and branches. Purchasing engine compartment-specific cleaning foam online is very convenient – it foams white upon spraying and breaks down grease. Keep the pressure of a regular water gun below 80psi, focusing on rinsing metal surfaces. The most challenging part is the accumulated dust in the gaps of wiring harnesses, which I slowly clean out using an old toothbrush and cotton swabs. After rinsing, leave the hood open for half an hour to dry. Finally, spraying a layer of tire wax can make plastic parts shiny black and prevent aging. Be careful to avoid the belt and motor areas, and ensure no dirty water flows into the coolant filler port.