Why is my pressure washer smoking

February 28, 2025

BISON Santy

Hello, I am Santy, the funder of bisonclean.com. I have been in cleaning machinery field for more than 5 years now, and the purpose of this article is to share with you the knowledge related to pressure washer from a Chinese supplier's perspective.

Pressure washers are useful cleaning tools designed to tackle even the toughest dirt and grime. But things can get concerning when you notice smoke coming from your machine. Whether you’re a professional contractor or a homeowner, seeing smoke coming out of a pressure washer can start to worry you. Smoking is a sign of a potential malfunction and a potential safety hazard that needs immediate attention.

Here BISON first announces a good news: although smoke may indicate serious problems, it does not always mean disaster. In most cases, identifying and fixing the issue is straightforward with the proper guidance. This blog will help you understand the common reasons why your pressure washer may smoke. In the end, you’ll learn what the smoke could mean and how to fix it.

Common causes of pressure washer smoking

Overheating

Excessive use: Continuous operation cycles of pressure washer beyond recommended durations induce thermal stress on mechanical assemblies, particularly the motor or engine.
Low oil levels: In gas-powered pressure washers, insufficient oil prevents proper lubrication, resulting in boundary layer friction and thermal accumulation within power generation modules.
Blocked cooling vents: This is a common problem in both gas and electric pressure washers. Compromised airflow channels hinder thermal regulation processes by impeding convective heat dissipation.

Solutions for overheating:

Turn off the machine immediately let it cool down, and ensure adequate airflow around the engine.
Avoid operating the machine in direct sunlight or extreme heat.
Check the motor or engine oil level before each use and top up with suitable oil.
Clean vents and heat sinks regularly to maintain proper airflow.

Oil leaks

Gaskets, deteriorated seals, or incorrect operation frequently lead to this issue. When oil leaks onto hot surfaces like the engine block or exhaust, it can burn and produce smoke. Exceeding the tank capacity will cause an overflow condition where excess oil can spill onto hot components where combustion can occur and smoke can be generated. Judging the cause of the oil leak by the color of the smoke:

White smoke: Typically reveals abnormal fluid consumption, potentially stemming from reservoir overfill or degraded compression rings permitting oil migration into ignition chambers.

Blue smoke: Indicates oil is burning, often due to leaks or aging seals in the engine.

Prevention and solutions:

Regularly inspect your pressure washer for oil leaks around the engine and seals. Secure any unstable fasteners or install renewed sealing components when necessary.
Ensure you’re using the correct amount of oil specified in the user manual. Clean up any oil spills and adjust the oil level to the recommended range.
If smoke persists beyond two operational cycles post-repair, consult a professional technician for a more in-depth inspection.

Fuel problems

Old or contaminated fuel: Using fuel that has been in the tank too long, has been depleted, or is contaminated with water or debris can cause incomplete combustion, which can produce white or gray smoke.

Wrong type of fuel: Using the incorrect fuel type (such as using diesel in a gasoline engine or vice versa) can cause heavy black smoke, engine puffing, or a failure to start.

Solution: Drain and change fuel, clean the tank, and fill it with fresh, clean fuel.

Pump problems

The pump is a critical component of any pressure washer, and issues within it can lead to excessive heat buildup – another potential cause of smoke.

How damaged seals and pump issues lead to smoke？

Water flow: Running a pressure washer with a clogged nozzle or without enough water can cause the pump to overheat, damage internal seals, and create smoke or a burning smell.

Internal pump damage: Worn or broken seals and components inside the pump can produce excessive friction, resulting in accelerated thermal energy accumulation.

Solutions：

Always ensure your pressure washer has sufficient water flow before starting it. Check the water source and hoses for any blockages or leaks.
Perform regular pump maintenance, such as checking seals, bearings, and correct pump lubrication.
If you suspect damage inside the pump, you should consult a professional repair service.

Engine issues (gas pressure washer)

Contaminated or obstructed combustion regulators disrupt the fuel-oxygen mixture equilibrium, resulting in incomplete combustion and white or black smoke.

Obstructed filtration units containing particulate matter limit fuel flow, creating over-concentrated mixtures that generate black smoke.

Aging machinery with compromised components including compression rings or valve gaskets may permit lubricant migration into ignition chambers, producing blue or white smoke.

Engine problem solutions:

When performance and smoke coexist, clean or replace the carburetor immediately.
Replace a clogged or dirty fuel filter to ensure proper fuel flow.
For aging engines that show signs of wear, professional help should be sought.

Electrical issues (electric pressure washer)

Electric pressure washers usually produce fumes due to an electrical fault or wiring failure.

Motor overload: Extended use or blocked cooling fans can cause an electric motor to overheat, producing smoke or a burning smell.
Wiring or connections: Compromised cabling, unsecured current pathways, or malfunctioning operational modules may induce arcing and create smoke.
Improper extension cords: Employing supplementary cabling incompatible with the cleaning apparatus’ energy specifications can cause resistive heating, elevating pyrotechnic incident risks.

Allow the motor to cool between uses, especially if it feels hot to the touch.

Check all electrical connections, including the power cord, for damage or exposed wiring. Replace damaged parts immediately.

Use only extension cords rated for outdoor use and of the proper amperage; check the manufacturer’s manual.

Troubleshooting steps for smoking pressure washers

1. Safety first

If your pressure washer emits smoke, turn it off immediately.

Electric models: Unplug the machine.

Gas models: Shut off the engine and disconnect the spark plug wire.

Keep the area you are working in ventilated, especially if the smoke is accompanied by the smell of burning oil, fuel, or electrical components.

2. Check the obvious

The color and behavior of the smoke will provide the strongest clues, and you can narrow down the cause of the smoke based on the color of the smoke and in the previous paragraph, “Common causes of pressure washer smoking.”

3. Let the machine cool down

Allow the pressure washer to cool completely before performing a thorough inspection or adding fluids such as fuel or oil. Failure to do so may result in burns or cause the oil, fuel, or other fluids to ignite.

4. Inspect key components

The color of the smoke will tell you whether to check the vents, connections, water flow, or pump. For the fuel pressure washer also check the oil level, exhaust system, spark plugs, fuel quality, and type.

5. Consult the owner’s manual

The owner’s manual provides specific instructions tailored to the design of your pressure washer and allows you to perform simple maintenance based on the owner’s manual, such as:

The correct oil and fuel types and recommended volumes.
Pump maintenance instructions and cleaning tips.
Model selection regarding parts or components.

Conclusion

It is unsafe to operate a pressure washer that is smoking. By understanding common causes such as overheating, low oil levels, contaminated fuel, or clogged vents, you can take effective steps to resolve the problem. Issues such as clogged filters or loose connections are easy to fix, but unresolved smoking may be a sign of pressure washer damage or a fire hazard. That’s why we need to intervene promptly on smoking pressure washers!

If you are still having issues or need to replace your pressure washer, BISON is here to help! Contact us, pressure washer supply company, to learn more about our professional-grade pressure washers to speak with a BISON expert for customizable product details. Take action now to expand your cleaning equipment market!

FAQs about pressure washer smoking

Is it dangerous to ignore the pressure washer smoking problem?

Smoking often indicates an underlying mechanical or electrical problem. Over time, this can warp sensitive components, such as seals, bearings, or gaskets, leading to total failure. In the event of worn parts, the cost of repairs can exceed the price of a new machine.

Operating a smoking pressure washer isn’t just bad for the machine—it can pose serious safety risks to you and anyone nearby. Extremely hazardous situations such as fire, electric shock, explosion, toxic fumes, etc. may be found.