Most of the time, the appearance of white “smoke” after a car wash isn’t smoke at all, rather, it’s water vapor and nothing to be concerned about.
However, in the rare instance it’s actually smoke, any reason for it is unlikely to cause significant issues and should be an easy fix.
But what could cause smoke after washing your car?
Reasons, why your car smokes and steams after a car wash, include:
In this article, I’ll cover several reasons why a vehicle may smoke or steam after a car wash and how you can distinguish between the two.
Reasons Why Your Car Might Smoke After a Car Wash
If you find that your vehicle emits white “smoke” immediately after a car wash, it’s essential to figure out what’s going on.
Most of the time, it’s just water vapor or steam — but sometimes, it could be true smoke caused by an undiagnosed problem.
An actual smoking vehicle after a car wash is far less common but may result from an issue that needs addressing.
Soap Burning Off the Engine
If you’re confident that you’re seeing smoke and not steam, it could be due to burning soap.
Any soap that seeps under the hood may burn off as the engine heats.
You’re likely to notice a strange smell, too (it may smell like the soap’s scent, although with a burnt odor).
This isn’t a cause for concern. Once the soap burns off, the smoke should cease.
Coolant Blown Around by Air Dryer
Though this is a less likely scenario, it’s certainly possible.
Undetected coolant leaks are common, and commercial car dryers may blow fluid around since the radiator sits at the front of the vehicle.
As the engine heats up, the coolant burns off, causing smoke. It’s often accompanied by a sweet smell.
Get the coolant leak fixed immediately if you notice a sweet smell and smoke.
Oil Blown Around by Air Dryer
While it’s unlikely that a commercial air dryer can blow oil around an engine, you can spread oil to other parts when washing the engine bay, especially if you’re just spraying the area with water (water and oil don’t mix) to remove any built-up grime.
If you spread oil to other parts of the engine, the oil burns off as the engine runs and is accompanied by smoke and the odor of sulfur.
Water Got Sucked Up Into the Intake
This situation is far less likely than the above scenarios. However, water can get sucked up into the intake.
Too much water causes hydrolock, leading to frozen pistons and a stalled engine.
It’s most common on vehicles that sit or drive through high floodwaters, not usually from washing the car.
It takes a significant amount of water to cause problems, so this isn’t a common occurrence.
Why Is My Car Steaming After Going Through a Car Wash?
If you notice steam after washing your vehicle, take note of where the steam is coming from.
A car steaming after going through a car wash may be due to condensation in exhaust pipes. Steam under a hood occurs when water evaporates off engine parts. If the entire car steams, it’s likely because the exterior is hotter than the surrounding air (usually after using hot water or an air dryer).
Steam rising from a vehicle after a car wash is not usually a cause for concern. Below, I’ll take a look at the many reasons why a car steams after a car wash:
Condensation Build-Up in the Exhaust
After washing a vehicle, especially when spraying the undercarriage, any water that contacts the exhaust pipes causes rapid cooling.
People often mistake water vapor coming from the tailpipe for white smoke.
While white smoke from the exhaust is a cause for concern, steam is not.
Once the engine starts up, warm air rapidly moves through the exhaust pipe, evaporating any water droplets and blowing them out in the form of steam.
Once the water evaporates, the water vapor dissipates within minutes.
Water on Hot Vehicle Components
According to the Milwaukee Area Technical College, the average operating temperature of a vehicle’s engine is between 180 to 190 degrees Fahrenheit (82.2 to 87.7 degrees Celsius) but may reach up to 220 degrees Fahrenheit (104.4 degrees Celsius).
Any water that leaks under the hood and lands on any vehicle parts (including fans, the condenser, radiator, alternator, etc.) eventually evaporates as the engine components heat up.
As steam rises from under the hood, many car owners panic, mistaking it for smoke. However, once all of the water evaporates, the vapor stops rising.
Running the vehicle for ten minutes after washing it should be enough to determine if you’re dealing with water vapor or smoke.
Additionally, washing the undercarriage can cause water to splash onto the catalytic converter.
Considering that the catalytic converter operates between 400 and 600 degrees Fahrenheit (204.4 to 315.5 degrees Celsius), any water that hits it will evaporate immediately, causing steam.
There are no serious mechanical issues associated with steam from a few water droplets under the hood.
The main concern is that the moisture causes window fogging as you drive.
However, allowing the vehicle to run for a few minutes allows the steam to dissipate.
It’s a Cold Day
If you take your vehicle through a car wash or wash it by hand on a cold day, you may notice steam rising off of the vehicle afterward.
This is most likely due to the air temperature. Using warm water or a commercial car dryer heats the car’s exterior.
When it contacts the cold air, you may see steam rising from the vehicle due to water vapor.
This is the same thing that happens when you breathe out on a cold day — the air condenses, causing steam.
As the exterior of the car cools down with the elements, the steam should stop.
This is totally normal and not something to worry about.
Your Car’s Heat Shield Needs Replacing
If you only notice steam coming from the hood on cold days, it could be that you need a new heat shield.
The heat shield helps protect the vehicle’s internal components and prevents body damage.
A damaged heat shield allows too much heat to come up through the engine bay and can damage the paint on the hood as it overheats.
This can also cause excessive steaming as water hits the hood of the vehicle during a car wash or rain storm.
Steam Vs Smoke
Below, I’ve created a table to help you distinguish between problems after a car wash that causes steam or smoke:
| Problem after Car Wash | Likely Cause | Steam or Smoke? |
| White “Smoke” from Exhaust (that dissipates after a few minutes) | Condensation in Exhaust | Steam |
| White “Smoke” from Under the Hood (that dissipates after a few minutes) | Water on Hot Engine Components | Steam |
| Thick white or gray smoke accompanied by a burnt, sulfur-like odor | Oil Leak Around the Engine Bay | Smoke |
| Thick white smoke accompanied by a sweet odor | Coolant Leak Around the Engine Bay | Smoke |
| White smoke with the smell of burnt soap | Burning Soap | Smoke |
| Entire Vehicle “Smoking” | The vehicle’s exterior is warmer than the surrounding air due to hot water or a warm air dryer during the car wash | Steam |
| Thick white smoke coming from the exhaust that doesn’t dissipate after a few minutes and smells of burnt oil | Water in Intake – If it’s an excessive amount of water, the smoke does not dissipate. If it dissipates after several minutes, it’s likely not a concern. | Smoke |
