Undercarriage Wash Safety: How to perform the washing Risk-free!

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Last Updated on 4 weeks by Ollie Barker

Undercarriage Wash Safety: How to perform the washing risk-free!

If your car is not in the best condition, it’s not unusual for you to need a wash job. Undercarriage washes are a simple and effective way to rid your vehicle of dirt, grime, bugs, dust bunnies — or whatever else may have accumulated under there. However, these “car washes” can be dangerous for the uninitiated. In this blog, I’ll give you an insight into undercarriage wash safety.

Undercarriage Wash Safety: How-to

If you’ve ever gone through an automatic car wash with a wash brush, you’re already familiar with the basics of how undercarriage washes work. These machines employ powerful spinning brushes to scrub your vehicle clean. However, we’re not going to trust our car to some high-powered machine, will we? That’s why we’re going to give it a good scrubbing by hand instead.

Before You Wash

Before you get started washing your undercarriage, make sure that the ground is completely dry.

If you live in an area with a lot of rainfall, this may not be possible. But, if it is, use a blower to dry it out. Otherwise, you could end up with dirty water dripping off of your undercarriage and back onto your paint job.

Start by jacking up your car on the ground. That way you’ll have instant access to even the lowest parts of your undercarriage – like the axle housing and wheel wells.

Items Needed

  • Electric pressure washer
  • Sandpapers (for rusted areas)
  • A Wash Mitt
  • Towels

Steps for a Safe Undercarriage Wash with a Pressure Washer

Before you start scrubbing, bring your garden hose to the highest possible setting. You’re going to need a lot of water pressure to get everything clean. If you don’t have enough water pressure, you’re going to need more than one hose, and there’s nothing worse than losing a battle with dirt and rust.

Attach your hose to a nozzle or spigot equipped with a “jet” setting.

Next, wash the underside of your car by following these easy steps:

• Start at the front of your vehicle
• Work from left to right
• Scrub each area thoroughly
• Rinse immediately after scrubbing

If you have access to a power washer, this is a safe alternative to hand washing. However, it’s important that you use it correctly.

Just like with a garden hose, you want to be careful about spraying the undercarriage of your car. That’s why it might be safer to use a sprayer dedicated to car washes.

Safe Scrubbing

Now that you understand how to hand wash your undercarriage, the next step is to decide what you’re going to use to scrub your car. You’ve got a few options, and they’ll all work in a pinch.

If you’re not up for the task just yet, go grab some towels first. You don’t want to risk going through an entire undercarriage wash without ridding yourself of any debris that could end up on your paint.

Once you’ve got your towels in hand, you can choose between sandpaper or a wash mitt.

Sandpaper is an effective way to scrub away rust and grime. It’s also the most affordable option, so it’s great if you’re on a tight budget. However, this scrubbing material can damage the paint on your car if you’re not careful.

Find out: Why did I stop using a sponge for washing cars?!

You should never use sandpaper on bare metal such as your rims without protecting them with a coat of wax first.

Wash mitts are the ideal tool for hand washing your undercarriage. They’re designed for one purpose only, and they do it well. You can pick up a wash mitt in most auto parts stores, and they’re relatively inexpensive as well.

I recommend that you buy a wash mitt that’s about the width of your palm. That way, you’ll be able to reach all of the puddles in between the wheel wells while you’re still standing on solid ground.

Cleaning Your Wheels

With that said, I can’t stress the importance of keeping your wheels clean enough! This is a mistake that many beginner hobbyists make. They want to get through their undercarriage wash as quickly as possible for fear of getting dirty. That’s no good. You want to take your time and give each part of your undercarriage a good scrubbing, including your wheels.

If you don’t, you’ll end up with a blank canvas of dirt and grime to work with. It could take you weeks to remove the grunge that’s already embedded in your wheels.

What About Rust?

Rust is one of the toughest enemies of undercarriage washes everywhere. Rust and paint don’t exactly get along, and there’s no way to get your car clean if it’s covered in rust. That’s why you want to be sure that your car is rust-free before you start washing it.

Unfortunately, there’s no way to be completely sure of your car’s integrity before you’ve started scrubbing. But, there are a few simple steps that you can take while you’re on the road to ensure that your undercarriage is fully rust-free before a wash is even possible.

First and foremost, make sure to inspect wheels that have had any kind of damage. If you see any signs of rust underneath, you’ll want to take immediate action on your car.

Next, keep your tires in top-notch condition. If you have any ruts or potholes in your driveway, you’ll want to cover them up regularly. You can’t wash your undercarriage if there’s dirt and dust hiding underneath your tires.

What Can Go Wrong With Incorrect Undercarriage Washing

If you aren’t sure what damages can you make with incorrect undercarriage washing? Let me tell you. There are 3 possible problems:

#1 Damage to Underbody Coating

Many people think that a washed undercarriage isn’t a problem and that the cleaner your car is, the better. Clearly, this is not true.

Even in automatic vehicles, there are usually some delicate components under the hood. These components are coated with a coat of paint in order to protect them from water and debris.

Check out: How anyone can wash a car without scratching its paint!

But if you don’t wash under there regularly (or at all), then they’ll easily get damaged by water and dirt.

#2 Joint Protective Rubbers

Plastic and rubber components are the backbone of any car. If these components are not taken care of during undercarriage washing, they can become perforated.

The first sign of this damage is that the wash water begins to drip out from under your vehicle. This problem can be solved by regular washing, but the joints will still wear out faster than expected. Sooner or later you’ll need to replace them if you want to avoid further damage.

#3 Car Electronics

Electronic car components need to be dried off after washing.

Here’s something that most people don’t know:

  • Car electronics are some of the most expensive components in your car.
  • Usually, they are located under the area, which we wash with the water jet during undercarriage washing. For this reason, after washing, you must make sure that these electronic parts do not get wet.


#1 How Often Should You Wash Your Undercarriage?

3-4 times/year

The best way to wash an undercarriage is to wash it as little as possible. This will allow you to enjoy your car’s underbelly for many years.

Washing less often also means that you are not wearing down or damaging any of the protective coatings on your undercarriage.

If you want to wash more often than 3-4 times per year, then you should be washing only the visible parts of your car, like the wheel wells and frame.

#2 Do Automatic Car Washes Clean the Undercarriage?

They do but not in an effective way.

Automatic car washes do not have enough pressure to properly wash the undercarriage. That’s because they have some kind of a pulse system that sends water into your car from all sides at the same time. This will not achieve proper cleaning results.

Check out: How to quickly dry your car’s seats in winter!?

#3 How Do You Degrease Undercarriage?

The best way to degrease the undercarriage of your car depends on its condition. If your undercarriage has a lot of rust, then you can use a chemical degreaser to dissolve it.

After that, you can use a scourer to clean it. Finally, there are those who prefer to do all of the work on the washing machine and then transfer it all into a tub for rinsing.

Final Words

Undercarriage washes are a great way to keep your car clean and in pristine condition. If you’ve never done one, you really owe it to yourself to give it a shot. But, if you’ve already done yours before some accidents have happened, you’ll need to take some extra precautions before treating your undercarriage again. Fortunately, there are several ways that you can do so safely and without damaging your paint job.