5 Reasons Why Your Car May Still Look Dirty After Washing

A puzzling problem that I have encountered a time or two after washing my car is that…well…it still looks dirty. While there is no one-answer-fits-all explanation for why this typically happens, there are a few common culprits worth diving into.

In this blog post, I’ll break down 5 plausible reasons based on my experience as to why your vehicle may still be looking a bit dirty even after washing it.

1. Using contaminated brushes or wash mitts

car wash buckets

One of the most common traps I sometimes see people fall into whenever washing their vehicle is using contaminated brushes and wash mitts.

For example, keeping a wash mitt in the same bucket as your wheel brush, or dipping a wheel brush in your wash bucket. Or it could be something as simple as not washing clean.

That is, forgetting to rinse off your wash mitt after making contact with your car.

All of this can lead to dirty water being applied to an already dirty vehicle, and one of the most common beginner mistakes. You always want to try to keep your water as clean as possible, so I always like to spray my mitt off before re-dipping.

While over time, the bucket will accumulate dirt, as long as there are thick, foaming suds covering your mitt you’re in the clear.

2. Not enough soap

filling wash bucket

On that same note, another common reason why you may not be achieving the results you desire is not using enough soap.

This has happened to me in the past, and most of the time it’s typically at the end of the wash where it becomes more difficult to generate suds. This is partly due to the dirt already in the bucket.

It’s important to clean a bucket out from time to time (especially when washing a larger car). Since dirt sinks to the bottom, it can eat up the remaining suds in the bucket, and make it difficult to create new suds with the hose.

Tip: Use a foam gun to always have enough suds to go around

For this reason, I prefer using a foam gun or cannon to wash my vehicle. If you do prefer the traditional bucket method, just be sure to always rinse your wash mitt, and to keep an eye on the amount of suds both in your bucket and on your wash mitt.

Without proper lubrication, dirt simply won’t be carried away when you graze a wash mitt over a dirty panel of your car.

While it may be inconvenient if you are close to finishing, again its best to rinse your bucket out and refill it with more soap whenever needed.

3. Hard water

hard water spots on car

One of the most frustrating reasons why your vehicle may still look dirty (even using a good wash technique) is often due to hard water. Hard water spots, or basically dried impurities found in water like calcium or magnesium, can sometimes appear to be a powdery-white color if severe.

Once dry, these spots aren’t always to easiest to remove. This is why so many people discuss using air dryers, or towels to remove water beads before they have a chance to dry.

Fortunately, there are a few things you can do if you suspect this is the root cause of your car appearing dirty. One of them is by using a portable water deionizer to remove these substances.

This is essentially a device you attach your hose to that filters your water.

Check out my post Washing Your Car With Hard Water? 3 Spot-Free Solutions for a few tips on solving this problem, and a few popular water deionizers on the market you can pick up specifically used to wash cars.

4. Dried soap

Ever heard that it’s best to wash your car in the shade? The primary reason why this is the case is that an extremely hot vehicle can just about dry soap on-contact.

Unless you use foam and water at the same time, it’s nearly impossible to completely wash dirty suds off of a flaming-hot car.

One workaround solution, if you are a detailer (or just someone looking to stay cool), is to purchase an auto detailing canopy to cool things off a bit.

auto detailing tent

You can pick these up on Amazon and are a great idea to set up for staying cool –especially if you normally take an hour or two to wash and detail your vehicle.

Check out this post I wrote to check out a few of these canopies that are affordable, portable, and ideal for washing and detailing.

5. Using an automatic car wash

car in automatic car wash

While car washes do have their place in certain contexts if you don’t have any alternatives, oftentimes they aren’t the best at cleaning dirt off of your vehicle. Especially with older car washes that still use flappers and brushes…these can be pretty filthy as it is!

If you notice a film of dirt even after running your car through one of these, it’s fairly common due to the fact that car wash soap is typically alkaline and good at removing oils, but isn’t so great on dust. 

This is why many mobile detailers either use friction (via brushes), or a more acidic cleaner in order to remove dirt and dust.

Some detailers that specialize in washing large semi-truck trailers use what’s called a two-step wash process, which uses both acidic and alkaline chemicals that can actually clean a vehicle without agitation.

This process contains chemicals that often aren’t used in consumer-grade car washes, however.


To conclude, if you are noticing your car is remaining quite dirty even after washing, you are likely dealing with hard water, an ineffective wash process,  or simply not enough soap.

When it comes to removing dirt, I have found that even with using a foam cannon to apply suds, it is good practice to graze a wash mitt over the area in order to release the static bond that dirt has on your car.

I hope this post helps to answer some of the questions you may have had about this process!

To learn about touch-free car washing, check out my post 5 Benefits of Using a Foam Cannon vs. Hand Washing.

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