How to Clean a Car Engine

Is your car or truck a grimy mess? Your engine is probably even more filthy! A well-kept car looks great rolling down the street, but you need to take pride in cleaning what’s under the hood too. If you’re a car fanatic, you’ve probably been degreasing your engine for years. Others might be thinking, “Wait, you’re supposed to clean the engine?” Read on to learn how to clean a car engine (and why it’s important!). Don’t feel like going through the trouble or have a fleet of vehicles you need to have serviced? Contact Manchester Fleet Services.

How Do I Clean My Car Engine?

A spotless engine is tough to achieve and even more difficult to maintain. However, it’s worth it! A clean engine compartment not only looks spectacular, but it also makes it easier to spot leaks or other issues right when they start, instead of having them be camouflaged by grime. This will keep your vehicle on the road longer and drive more efficiently. These are important factors for any vehicle owner, and especially vital for a business with multiple vehicles needed to keep operations moving.

Even though the engine bay is not exposed to the elements from above, debris can creep in from openings around the hood or through the vehicle's front end. Your car’s engine will run better after a cleaning. You’ll feel like you just rolled it out of the showroom.

Cleaning your engine might sound like a huge undertaking. Follow these 10 steps to turn a daunting task into a simple afternoon of work. Here's how to clean your engine quickly and efficiently:

Step 1: Pick a nice day.

Try to clean your engine on a warm, sunny day. Warmer weather will help dry the engine and components after cleaning. A day with low humidity would also be good. If rain or a storm is on the way, reschedule this project.

Step 2: Let your engine cool.

If you just drove your car recently, make sure you flip the hood up and allow the engine to cool for at least 15 minutes before attempting to clean it. Hot engine components can burn you! Plus, washing the engine while it’s too hot can produce steam that causes cracks in plastics and wire/battery corrosion. Engine components can also be damaged by rapid contraction if you spray them too soon with cold water.

Step 3: Snap a picture before taking things apart.

Even if you think you have a photographic memory and you’re armed with a wealth of reference materials, having a photo as backup may prove invaluable. Sometimes, all it takes is a slight glance at your “before” photo to know where that weird-looking hose should be attached. It’s also a great reference to look back at all the improvements you made.

Step 4: Remove any plastic covers under the hood.

These covers can be scrubbed separately. You’ll also need to remove the negative terminal from the battery to protect the electrical components from getting damaged if they accidentally get wet. You can also remove the battery if you’d prefer, but it’s not necessary.

Step 5: Cover all electrical components.

Cover any sensitive electrical components (the battery, ignition wires, and engine control unit) with plastic bags. If there's an exposed engine air intake under the hood, you should cover that also (unless you can be extra careful with your rinsing). However, protecting your electronics will allow you to clean more thoroughly without constantly worrying about damaging something.

You should also wrap ignition wires and coils and all electrical connectors with plastic wrap. Add some fluorescent surveyor’s tape. Then you won’t forget to remove the wrap later!

Step 6: Degrease!

An engine degreaser works best when the grease is warm and soft. Start the engine and let it run for about five minutes; this will give you the best cleaning results. You must shut it off and let it cool down before touching the exhaust manifold, however. Never spray engine cleaners (especially flammable solvent types) on a hot engine.

Thoroughly spray the entire engine compartment with the degreaser. You can use any household degreaser (kitchen cleaner or a purpose-made engine degreaser, both will work fine). You may also try Simple Green (the eco-friendly formula is fantastic!). Don’t be skimpy with the degreaser — spray every square inch!

Step 7: Scrub your engine.

This step depends on how dirty your engine is — you may not need to scrub! However, some areas, like the valve cover, may have caked-on oil and dirt that have been accumulating for years. A small brush with synthetic bristles will aid the degreaser in cleaning out the gunk. Add more degreaser if needed. As we said before, don’t be skimpy with the degreaser!

Step 8: Rinse.

If you want to use a power washer, make sure you have it on a light setting. However, a standard hose will work just as well. Just don’t use a high-pressure nozzle. (You can even use the sprayer at your local Do-It-Yourself car wash if you don’t have anything to use at home.) Make sure to rinse the entire compartment back to front, washing away all the degreaser. Try to avoid directly spraying electrical components.

Step 9: Dry.

If you have an air compressor, you can blast air in all the nooks and crannies to remove excess water. If you don’t have an air compressor, just wipe everything the best you can with a towel or shop rag. This will remove water as well as any remaining grime.

Never let your engine air dry. Wipe it down with a clean microfiber towel after a few minutes.

Step 10: Replace.

Reinstall the negative terminal on the battery and remove the bags covering the electrical components.

Step 11: Repeat

If you want to make this project simple, don’t let your engine compartment get excessively dirty. If you do a quick degreasing every year, it will help your engine stay clean with no more than an hour of work.

Why Should I Clean My Car Engine?

The No. 1 reason is that a clean engine is easier to work on. When something goes wrong under the hood, you can see what you are doing!

Thinking about selling your car in the future? The second reason you should clean your engine is it will be worth more when you go to sell it. Who doesn’t look under the hood when they go to buy a new car? If your engine is sparkly clean, a potential buyer will be more likely to put up the cash.

How Much Does It Cost to Get Your Engine Cleaned?

Costs range from $100- $400 depending on your engine type. Residue from materials left in your engine after the cleaning process may result in premature engine failure, so it’s important to have your engine cleaned properly.

Now you know how to clean a car engine. But most fleet operators don’t have the time to perform a thorough engine cleaning, let alone the experience to do it correctly. So you can take your vehicles to be serviced by a professional. That way, you can be sure of a well-maintained vehicle that will stay on the road for you.