Skip to Content

De Walt Pressure Washer Problems: Engine & Motor Troubleshooting & Repair

De Walt is a trusted power tools manufacturer that produces gas and electric pressure washers. Despite its reliability, your De Walt pressure washer might occasionally give off some performance glitches that could affect your normal cleaning operations. This article provides a troubleshooting guide to help you fix these issues for all types of De Walt pressure washers.

De Walt Pressure Washer Problems

If your De Walt pressure washer engine doesn’t start or stalls, examine the carburetor jets and the air and fuel filters. Check that the tank vents are clear and that there is no vapor lock in the fuel lines. For an electric pressure washer to function correctly, the input voltage must be within limits prescribed, and the power supply shouldn’t be defective. If the motor makes a buzzing noise, look for a bad capacitor, a damaged pump, or a pressure buildup in the system.

In the following sections, I will look at both gas and electric pressure washers made by De Walt. The possible problems that may occur are mentioned along with their solution strategies.

Problems with the De Walt Gas Pressure Washer Engine

A four-stroke petrol engine powers the pump in gas pressure washers. The presence of the engine and fuel system components increases the total complexity of the system, hence raising the maintenance requirements. This eventually makes these models more prone to undergo problems.

Here are some of the most common problems with your De Walt pressure washer engine.

● 1. De Walt Pressure Washer: Keeps Stopping and Starting

If your pressure washer starts and stops repeatedly, it might be due to a clogged carburetor jet or a vapor lock in the fuel lines. A defective fuel filter may sometimes be the source of the problem.

Most engine problems in pressure washers are due to an issue with the carburetor or the filters. The carburetor jets are likely to become blocked due to stale fuel deposits. Hence, the amount of gasoline reaching the engine impacts combustion, decreasing engine power output.

Besides carburetor or filter clogging, a vapor lock is another typical cause of the problem. A vapor lock is created by a continuous accumulation of gasoline vapors within the fuel lines caused by an obstruction in the fuel tank vents.

– Solution:

To resolve the issue, carefully clean the jets of your carburetor with WD-40 or a carb-cleaner solvent. Ensure that all flow passageways have been thoroughly cleaned, including the bowl’s nut, which is a jet in itself. Aside from carb cleaning, you should examine and change your fuel filter. I also recommend cleaning the fuel tank vents to prevent vapor accumulation that might cause a vapor lock.

● 2. De Walt Pressure Washer: The Engine won’t run

If your engine doesn’t start, check to see if the spark plug is in good working order. If the problems continue, dismantle the carburetor and use carburetor cleaning liquid to clean the ports.

Carbon buildup wears away spark plug electrodes over time, reducing spark quality and making the engine starting harder.

– Solution:

Remove the spark plug to inspect the electrodes. If the electrodes appear to be damaged, replace the plug. If the problem continues, consider examining your pressure washer’s carburetor. Remove the carburetor and properly clean it to eliminate any remaining fuel. I recommend getting a carburetor repair kit for your brand and model to help with the repair. Often they include a cleaning solvent to remove sticky residues.

● 3. De Walt Pressure Washer: Engine Stops

If your engine stalls quickly after starting, you should thoroughly inspect and clean the air and fuel filters. Check the tank for vapor lock and ensure the carburetor is clean and properly adjusted.

The air and fuel filters keep harmful particles out of the carburetor. As a result, these filters become clogged with dirt regularly, changing the engine’s air-fuel mixture and resulting in power loss.

– Solution:

Inspect these filters separately and clean/replace them as needed to resolve the issue. If the problem persists, check the gas tank for vapor lock and adjust the carburetor screws.

● 4. De Walt Pressure Washer: Engine not providing enough Power

If your engine isn’t producing enough power, check the water supply and make sure the hoses aren’t kinked. Make that the air filter and carburetor jets are clean.

The air-fuel mixture may be too high if the engine isn’t producing enough power. This means the engine is getting too much gas but not enough air to create enough power after combustion. The carburetor, filters, or both might cause the problem.

– Solution:

To ensure adequate air supply, examine the air filter, which should not be blocked with dust. Moreover, the L and H screws on the carburetor should be correctly adjusted. The engine’s RPMs are controlled by these screws at both low and high speeds.

Also, ensure no air is trapped in the pump and that the hoses are not kinked since this generates severe back pressure on the engine. Hence, it may not deliver enough power.

● 5. De Walt Pressure Washer: Oil Leak

The most common cause of oil leaks in your engine is a faulty seal. In almost all circumstances, replacing the seal would fix the problem. Oil may also spill in rare occasions due to an overfilled oil reservoir.

You may purchase an oil seal kit to assist you in replacing seals as needed. Oil seals can be found in oil inlets. Two inlets on either side of the engine are generally covered with caps.

– Solution:

With a screwdriver, remove the seal and inspect its condition. Replace it if it appears to be damaged. As a precaution, you should avoid overfilling your oil tank, as this may result in oil pouring from these inlets.

● 6. De Walt Pressure Washer: Water in Oil

If water enters the engine oil, the oil seal is weakened. In this situation, you should replace the seal according to the manufacturer’s instructions.

When you add water to the oil, it turns milky. A damaged oil seal is a possible cause, and a worn-out engine piston is another less likely cause. Mechanical wear causes metal to break off from pistons over time, increasing the gap between the piston and the cylinder walls.

As a result, water entering the piston via the inlet manifold may enter the crankcase and blend with oil to create a milky suspension.

– Possible Solutions:

If your engine is less than 5 years old, the seals/gaskets are most likely faulty. As a result, you’ll need to replace the seal/head gasket on your engine. Contact the manufacturer if your engine is still under warranty and request this replacement. I would not advocate putting your warranty at risk by replacing it yourself.

In the instance of a worn-out piston, check with the manufacturer to see if the engine’s warranty is still valid. If not, the engine in your pressure washer may need to be replaced.

De Walt Electric Pressure Washer Problems

Electric pressure washers require less maintenance than their gas-powered counterparts, as using an electric motor reduces the system’s complexity. Moreover, the risk of malfunctions, as well as noise levels and pollutants, is generally lower. As a result, these devices have grown in popularity in the market.

This blog article addresses difficulties with the start-up procedure of electric pressure washers. The most common motor-related issue with electric pressure washers is the motor not starting or abruptly stopping while in operation. It may occasionally generate a buzzing noise without producing any power output.

● De Walt Electric Pressure Washer not running

Check the fuse and ensure the electrical outlet is operational if an electric pressure washer does not start. If it still does not start, the electric motor may have failed.

Examine the following if your pressure washer motor isn’t working:

– Step 1: Check for Power Outlet Issues

If your electric pressure washer isn’t working, first check the outlet. Unplug the pressure washer and inspect the outlet using a voltage tester or other tools. If it doesn’t function and you see a ‘reset’ button, press it. Check the circuit breaker in the fuse box if this does not work.

– Step 2: Examine the Fault Circuit Interrupter.

Because of the voltage drop, a ground fault circuit interrupter (GFCI) may have been engaged. Reset the GFCI after removing the pressure washer plug. If it still engages when you attach your pressure washer when it is wet, let it dry before starting again. There is an issue if the pressure washer continues to stop after drying.

– Step 3: Inspect the Extension Cord

Remove the extension cable from your pressure washer and try plugging it in directly. Check that the plug is inserted correctly into the power outlet. If it works now, the issue was with the extension cable.

– Step 4: Examine the Fuse

If the power outlet works correctly (with a bulb or other appliance), ensure the fuse within the machine or at the plug of its cord hasn’t burned out. Look in the guidebook if you can’t locate it. If the fuse has blown, it must be replaced.

– Step 5: Examine the power cord

If it still doesn’t start, the power cord may be faulty. The issue might be resolved by changing the power cord. Check with your pressure washer manufacturer to check whether the warranty is still in effect. If not, you should consider changing the chord on your own.

– Step 6: Inspect the Capacitor

A faulty capacitor usually causes a buzzing sound from your pressure washer’s motor. You can replace the capacitor on your own, but if you are unsure how to do this, ask a professional for help.

If the machine still doesn’t start, examine and replace the electric motor if it’s still under warranty.

● De Walt Electric Pressure Washer Motor Stops

A power failure in the socket or a faulty capacitor is the most typical cause of pressure washer motor failure. A voltage drop in the socket may occasionally cause it to shut off.

The motor automatically shuts off when the voltage falls below a certain threshold. Using a multimeter, check the voltage level in the socket. Pressure washer voltage requirements vary depending on where you reside. Pressure washers are commonly powered by voltages ranging from 140V to 240V.

If the voltage is correct, but the washer does not start, the capacitor in the motor may need to be changed. A clear sign is when your motor is humming and provides little power. Replace the capacitor with an equivalent model and re-inspect the pressure washer motor. Hopefully, it will restart soon. If it still won’t start, your manufacturer needs to repair or replace the malfunctioning electric motor.

● De Walt Electric Pressure Washer Motor Makes a Buzzing Noise

A buzzing noise from your electric pressure washer engine suggests a damaged capacitor or too much pressure buildup in the system. A faulty pump could be the source of the issue.

  • Capacitor: The most typical cause of the motor humming might be a malfunctioning capacitor. Motor RPMs are reduced by insufficient charge storage. To fix the issue, you should replace the capacitor and check whether it works well now.
  • Low Voltage: If the supplied voltage is lower than the pressure washer’s operating range, the motor may not operate at its specified RPMs and instead emit a buzzing noise.
  • Pressure Buildup: When the spray gun is not released, water pressure builds up in the hoses. This creates back pressure on the pump and, as a result, the motor, affecting its rotational speed. Test the motor by pressing the spray cannon to relieve the pressure.
  • Damaged pump: Pressure washer pumps can be damaged due to poor maintenance. In that case, the motor overheats because the pump fails to generate adequate pressure. To guarantee that the pump functions, check that the pistons and plungers are adequately lubricated. If not, consider replacing the pump.

De Walt Pressure Washer troubleshooting table:

Pressure washer not producing high pressure
Hose with small diameter
Replace your hose with a 1″ (25mm) or 5/8″ (16mm) hose
Restricted water supply to the washer
Check for the kinks and leaks in the hose
Inadequate water supply
Ensure the water source is unobstructed and fully turned on
Clogged intake filter
Remove the filter and rinse it with warm water
Air in the pump
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
Suction tube or detergent bottle not connected properly
Install the suction tube and detergent bottle correctly
Detergent too thick
Dilute the thick detergent by adding water
Obstructed spray tip
Remove the debris with a needle
No pressure tip on the wand
Install a suitable pressure tip at the end of the wand
If your model has a belt, it can be loose.
Tighten or replace the belt.
Pulsing pressure washer (output pressure varies high and low)
Inadequate water supply
Ensure that the water source is fully on and check the hose for kinks and blockage
Obstructed spray tip
Remove the debris with a needle
Pump sucking air
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
Clogged intake filter
Remove the filter and rinse it with warm water
Calcified hose, tip, or trigger
Clean the hose, pressure tip, or trigger with vinegar or a cleaner designed for this purpose
Noisy Pump
Air in the pump
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
Clogged inlet filter
Remove the filter and rinse it with warm water
Pump leaking water
Damaged or worn water seals
Replace the seals with new ones or call a professional
Loose fittings
Ensure that all the fittings are tight
Erratic water pressure, changing up and down
Unloader valve
Check and clean the unloader valve. If in bad shape, replace it
No output pressure. Or the motor stops when using the trigger (electric models)
Unloader valve
Check and clean the unloader valve. If in bad shape, replace it

● De Walt Gas Pressure Washer Engine troubleshooting table:

Leaks in the spray wand, spray tip, or extension
Damaged or broken O-rings or plastic insert
Replace the worn O-rings or call a professional
Pressure washer pump dripping oil
Worn or damaged oil seals
Inspect the oil seals and replace if worn
No water from the washer outlet
The water supply is off
Turn the water supply ON
Kink in the hose or faucet not fully open
Remove any kinks and debris from the hose or water lines. Check and fully open the faucet.
Motor won’t start
Check the battery
Check if the battery is charged correctly. Charge or replace when in bad condition. Examine the battery terminals for a proper connection. Clean if needed.
Check the fuel filter.
Clean the fuel filter if dirty. In that case, check the gas tank, as this is the most likely culprit.
Check the gas supply.
Check the fuel level and add if needed. Ensure that the gas can flow to the carburetor. Remove any blockage.
Check the Air-filter
Clean the air filter. Replace it when it is in bad condition or a paper air filter.
Check the carburetor
Remove and clean the carburetor with some carb cleaner. It is also possible to clean it without removing it.
Fuel gap blocked
Check that the hole in the fuel cap is open. Clean if needed.
Engine is stalling, or starts and stops
Check the carburetor
Remove and clean the carburetor with some carb cleaner. It is also possible to clean it without removing it.
Air filter
Clean the air filter. Replace it when it is in bad condition or it is a paper air filter.
Check for bad gas
Suppose you have old gas, more than a few months old. It can turn bad. Drain and replace the gas. Next time add a fuel stabilizer.

● De Walt Electric Pressure Washer Motor troubleshooting table:

Motor won’t start
The power switch is in the “OFF” or “0”  state
Turn the power switch “ON” or “1”
Cord not plugged
Plugin the power cord
Damaged, too long, or improper extension cord
Replace the existing cord with a 25′ (7.6m) 14 AWG cord or a 50′ (15m) 12 AWG cord
Inadequate power from the electrical outlet
Plug the cord into a different outlet
The pressure washer circuit breaker tripped.
Wait for the washer to cool down and restart it
Motor buzzes but fails to run
Loss in voltage due to the extension cord
Plug the unit directly into the outlet without an extension cord. If the problem isn’t solved, replace the extension cord.
Low supply voltage
Ensure that only the pressure washer runs on that circuit at the time of use
Residual pressure in the system
Shut off the washer and squeeze the trigger to release pressure
Residual friction among the internal components
Cut the water supply and turn the machine ON for 2 to 3 seconds. Try it a couple of times or until the motor starts. Don’t let the machine run dry for more than 3 seconds.
Unit not used for long periods
I recommend asking a Professional for help.
Motor not working
Faulty Timer
Disconnect the leads from the timer. If your pressure washer doesn’t turn off after the time out, it means that the timer is faulty and you need to replace it.