How to Safely Clean an Engine: A Step-by-Step Guide

Cleaning an Engine: Do’s and Don’ts

A clean engine is not only aesthetically pleasing but also helps you spot potential issues more easily. This guide provides a comprehensive step-by-step approach to clean an engine, ensuring you do it safely and effectively.

Cleaning your engine is easy for any DIYer as long as you follow some pretty important rules about protecting electrical connections. If you don’t know what you’re doing, you can screw things up royally. There are many components under the hood that can be damaged by degreasers and water.

Tip #1 Never clean an engine with a power washer

It sounds like a quick, easy way to clean an engine without much scrubbing. That part is true. The problem is high pressure. It forces water into electrical connectors and electrical components that should never come in contact with water. Even if you’re careful to avoid electrical connectors, it’s just not a good idea. Don’t do it.

Tip #2 The rinse water is considered toxic waste

It doesn’t matter if you’re using a biodegradable degreaser; the grease you’re washing off isn’t biodegradable. If you just flush it down your driveway into a storm sewer, you’re polluting rivers and streams. So you have to take some precautions to capture the oil and grease, or at least do it at a car wash that can handle the waste water. I’ll show you how to do that.

Tip #3: Take the time to prep electrical connectors

Most electrical connectors on late-model engines have silicone waterproof seals. Well, they were waterproof when the vehicle came off the assembly line. Years later, those same connectors might not be so waterproof. So it’s best to protect them.

Clean an engine Step-by-Step

Step 1: Start the engine and let it run until it’s warm.

That will soften the grease and help the degreaser to work faster

Step 2: Remove the air filter box and intake duct.

Then, seal the throttle body with cling wrap and a rubber band.

Step 3: Wrap electrical connectors with cling wrap.

Wrap cling wrap around your alternator.

Step 4: Lay an oil-absorbing mat under the engine.

Pig Mat is a product that absorbs oil and grease but sheds water, preventing pollution. You can find it at any auto parts store.

Step 5: Spray degreaser on the engine and around the engine compartment.

Use a nylon brush to scrub the lightly soiled areas to remove dirt and oil residue. Use a wire brush on heavily greased areas to speed up the dissolving process. Repeat the degreaser application as the grease breaks down.

Use degreaser products and wire and nylon brushes to clean an engine. Use wire brushes on baked on grease. Use nylon brushes on plastic parts.

Step 6: Using your garden hose and a nozzle, shoot water between the radiator fins and the condenser coil to remove dust/dirt buildup from your radiator.

Repeat the process on the front of the condenser coil.

Step 7: Rinse with a garden hose and nozzle, avoiding hard streams.

Continue degreasing, brushing, and rinsing until the engine is clean.

Step 8: Use compressed air or a leaf blower to blow off as much water as possible.

Step 9: Wipe engine and compartment areas with a rag.

Step 10: Remove all the cling wrap from the alternator and wiring connectors.

Remove the cling wrap from the throttle body and re-install the air duct and air filter box.

Step 11: Start the engine and let it warm up to dry off any remaining water.

Then take it for a spin.

©, 2020 Rick Muscoplat