How to Clean the Undercarriage of Your Car in 8 Steps

Written by

Bruce Sonnier


Marcus Dutton

how to clean the undercarriage of your car

As the undercarriage is the part of your car closest to the road, it is prone to accumulating dirt, debris, and road salt, as well as getting moist from the rain, mud, and snow. Eventually, these things lead to the wearing and rusting of the undercarriage, especially if it’s neglected. The car’s performance would also be adversely affected.

So on your next trip to a car wash, it would be wise to get a car wash with undercarriage cleaning. But if you’re willing to do it yourself, here’s a guide on how to clean the undercarriage of your car.

Step-by-Step Guide


Car undercarriage cleaning may seem like an overwhelming task due to the fact that it’s a hard-to-reach area and is likely very dirty due to its proximity to the ground. But with the help of a car jack, along with other handy tools and products, you’ll be able to wash it yourself.

What to Prepare

  • Car jack
  • Pressure washer
  • Degreaser e.g. WD-40
  • Spray bottle
  • Car cleaning agent
  • Brush
  • Tar remover
  • Towels and/or blow dryer
  • Undercarriage Protectant

Detailed Steps

Step 1. Use a Car Jack to Lift Your Car


You’ll first have to lift your car with a car jack, since you’re going to pressure wash under car.

If the car is not elevated, the water being sprayed may cause rocks and dirt to bounce around and make more mess and damage on some components.

Lifting your vehicle would also help to expose the undercarriage for a thorough cleaning. But if your ride is a lifted truck, then there’s no need to do this step.

Step 2. Take the Wheels off the Car (Optional)

Taking the wheels off your car would also be a good idea for you to be able to move freely as you wash undercarriage of car. But this is just optional, and you don’t have to do it if you prefer not to.

But it would be advisable to take them out if your car’s undercarriage is very dirty. That way, you’d be able to really get into the contaminants on the surface.

Step 3. Rinse the Undercarriage With a Pressure Washer


Once you got the undercarriage all set for cleaning, give it a thorough rinse using a pressure washer to remove the loose contaminants. Rinse it section by section, starting from the front part of the undercarriage, moving to the back to ensure that all parts of the undercarriage get cleaned.

A spraying technique that’s effective most of the time when rinsing your car’s undercarriage is to hold the wand at an angle of 45 degrees. However, depending on how your body is positioned, it can be difficult to do.

But if it’s possible for you to do the technique, this will help get rid of more contaminants from the undercarriage. Try not to spray too much on the surface though.

Step 4. Pretreat Extra Oily and Greasy Parts With a Degreaser


Some areas in the undercarriage, like the electric parts and engine parts in the front, tend to be very oily and greasy. Get rid of the excess oil and grease from these areas before you do the undercarriage car wash by spraying a degreaser on them.

Leave the degreaser on the undercarriage’s surface for 20 minutes to let it work on all the oil and grease. Then rinse the surface again.

Step 5. Wash the Undercarriage Using a Pressure Spray

After allowing the degreaser to work on the excess oil and grease, apply a cleaning agent onto the undercarriage using a spray. If you don’t have a spray, you can use a spray bottle instead.

Let the cleaning agent sit on the undercarriage’s surface for a few minutes. Then scrub the surface with a brush.

When you’ve finished scrubbing the entire surface, give it a rinse using the pressure washer.

Step 6. Clean Stubborn Tar and Other Contaminants With Tar Remover

If some stubborn tar and other contaminants are left over on the surface after trying to clean undercarriage of car, you can use a tar remover on them. With it, your car’s undercarriage will be spotless with no more stickiness.

Step 7. Dry the Undercarriage

If the undercarriage is left moist, rust can develop on it, so make sure to thoroughly dry every part of the undercarriage when you do an undercarriage wash. You can use towels or a blow dryer.

Step 8. Apply Protectant on the Undercarriage


Finally, when your car’s undercarriage is clean, it would be necessary to apply a protectant on it to shield it from moisture, salt, dirt, rocks, and other things that can damage it. A protectant can also help keep the undercarriage clean.

There are different types of protectants, and each of them has its own purposes. You can see the different options for protectants for an undercarriage below:

  • Rubberized undercoating – When applied, a rubberized undercoating would help prevent moisture, rust, dents, and dings. Rust-oleum and Dynatron make some of the best products of this type.
  • Asphalt-based undercoating – It’s a stronger protectant that works well for recreational vehicles, large trucks, and heavy machinery. This type can seal up cracks and reduce noise from the carriage, but it’s pretty expensive.
  • Polyurethane undercoating – This undercoating works as a sealant that protects against corrosion and humidity. It can last around three to five years and reduce noise, similar to rubberized formulas. However, when using this, there are some preparatory tasks you need to do first, such as sanding and applying etching primer onto bare metals.
  • Wax or paraffin-based undercoating – Among all the options, this is the cheapest undercoating, which is great news for people with small budgets. However, its smell can be unpleasant, and its protection may decline with just small abrasions.
  • WD-40 – Even just a lubricating oil such as WD-40 can protect your car’s undercarriage. This would help waterproof it at the same time. WD-40 also has other effects, such as cleaning bugs off car, you can read more here.

You can choose whatever protectant that suits your needs. But generally, a rubberized undercoating would usually suffice.


Doing these steps on how to clean the undercarriage of your car would help keep your vehicle free of rust, prevent it from getting damaged, and allow you to drive smoothly. So don’t neglect your car’s undercarriage and give it an underbody car wash when necessary. Furthermore, if you understood the above steps well, you can learn more about how to clean your entire car with a pressure washer and how to dry your car after washing. 

5/5 - (3 votes)



"As the content writer of Charmcitycirculator, I intend to bring just the best purchase options and straightforward answers to your problems. Other than what we put up on our website, we hope to hear more from you. "

– Bruce Sonnier