Pressure washer engine surging, also known as pulsing, refers to the inconsistent flow of water from the pressure washer, causing the water pressure to fluctuate between high and low levels. This issue can significantly hamper the cleaning process and potentially damage the machine components if left unchecked. In this comprehensive guide, we will delve into the common causes, diagnosis, and repair steps for a surging pressure washer engine, providing you with a detailed manual to tackle this problem effectively.
Common Causes of Pressure Washer Engine Surging
- Kinks and Blockages in the Hose or Pump:
- Ensure all connected hoses are free of kinks, leaks, and obstructions. Check that all hoses fit and are correctly connected.
- Hose diameter should match the pump’s inlet and outlet ports, typically ranging from 1/4″ to 3/8″ for most residential pressure washers.
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Inspect the hose for any signs of wear, cracks, or damage, and replace it if necessary.
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Plugged Nozzle:
- Clean or replace the nozzle if it is clogged. Use a thin metal wire or a nozzle cleaning kit to clean the inside thoroughly.
- Nozzle orifice size is crucial for maintaining the correct water flow and pressure. Refer to the manufacturer’s recommendations for the appropriate nozzle size.
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Ensure the nozzle is not worn out, as this can lead to a decrease in water pressure and cause surging.
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Pump Packing:
- Inadequate pump packing can cause surging. Check the water supply and ensure the pump gets enough water from the source at the minimum GPM (gallons per minute) required.
- The minimum water supply for most pressure washers is typically 2-4 GPM, depending on the model and engine size.
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Ensure the water inlet filter is clean and free of debris, as a clogged filter can restrict water flow and lead to surging.
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Air in the Pump:
- Trapped air in the pump can cause surging. Check and remove air from the pump and hose.
- Bleed the air from the pump by running the pressure washer with the gun open until a steady stream of water flows without any air bubbles.
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Check the pump’s inlet and outlet connections for any air leaks and tighten them if necessary.
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Dirty Inlet or Discharge Valve:
- Clean or replace dirty valves that may not open and close properly, leading to irregular water pressure.
- Inlet and discharge valves should be inspected for wear, cracks, or deposits, and replaced if necessary.
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Valve clearances should be within the manufacturer’s specifications, typically ranging from 0.004″ to 0.008″ for most pressure washers.
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Faulty Pressure Regulator:
- Replace the regulator if it is damaged or malfunctioning, as it controls the water pressure.
- Pressure regulators are typically set to maintain a specific pressure range, often between 1,500 to 3,000 PSI for residential pressure washers.
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Ensure the pressure regulator is functioning correctly and not stuck or worn out, as this can cause pressure fluctuations.
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Worn Pump Seals:
- Replace worn or damaged pump seals that allow air to enter the pump, causing pulsations.
- Pump seals should be inspected for wear and replaced according to the manufacturer’s recommended service intervals, typically every 100-300 hours of use.
- Ensure the pump seals are compatible with the pressure washer model and the type of water being used (e.g., cold, hot, or chemical-laden).
Diagnosis and Repair Steps
- Check the Spray Nozzle:
- Ensure the nozzle is clean and not clogged. Attach another nozzle to see if the surging problem persists.
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Measure the nozzle’s orifice size and compare it to the manufacturer’s recommendations to ensure it is the correct size for your pressure washer.
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Check the Unloader Valve:
- Ensure the unloader valve is not blocked or worn out. Adjust the valve slightly to increase washer pressure, but be cautious not to exceed 10% pressure spikes.
- Unloader valves are typically set to a specific pressure range, often between 1,500 to 3,000 PSI for residential pressure washers.
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Refer to the manufacturer’s instructions for the proper adjustment and maintenance of the unloader valve.
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Check the Hose and Filter:
- Ensure the hose is free of kinks and restrictions. Clean the hose and filter thoroughly.
- Measure the hose diameter and length to ensure it matches the pressure washer’s specifications. Longer hoses or smaller diameters can restrict water flow and cause surging.
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Clean or replace the water inlet filter if it is clogged, as this can also lead to pressure fluctuations.
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Check the Water Supply:
- Ensure the pump gets enough water from the source at the minimum GPM (gallons per minute) required.
- Measure the water flow rate at the pump’s inlet using a flow meter or by timing the fill of a container with a known volume.
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Ensure the water supply is not restricted by any valves, kinks, or obstructions, and that the water pressure is within the recommended range, typically between 20-100 PSI.
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Check for Air in the Pump:
- Disconnect the hose from the pressure washer and let water flow until only water comes out. Reconnect the hose and check if the surging issue persists.
- Inspect the pump’s inlet and outlet connections for any air leaks and tighten them if necessary.
- Ensure the pump’s inlet strainer is clean and free of debris, as a clogged strainer can allow air to be drawn into the pump.
Technical Specifications and Safety Precautions
- Safety: Always disconnect the pressure washer from the power source before starting repairs. Wear protective gear, including gloves and safety glasses, to protect yourself from potential harm.
- Maintenance: Regularly clean the exterior of the pressure washer and check its components for any signs of wear and tear. Ensure all parts are functioning correctly and replace any that are worn out or damaged.
- Storage: Store the pressure washer in a dry, protected space to keep it safe from the elements. Protect the pump from freezing temperatures during winter months.
Reference
- Bison Industry. (2023, November 2). Pressure washer surging/pulsing (How to fix it?). Retrieved from https://www.bisonindustry.com/news/pressure-washer-surging-pulsing/
- BobIsTheOilGuy. (2022, April 25). Pressure washer surging issue. Retrieved from https://bobistheoilguy.com/forums/threads/pressure-washer-surging-issue.354158/
- Bisongenerator. (2023, November 3). Pressure washer is surging/pulsing: An in-depth comprehensive guide. Retrieved from https://www.bisongenerator.com/Blog/pressure-washer-surging-pulsing.html