What are the reasons for a three-cylinder plunger pump having no pressure?
2 Answers
Below are the reasons why a three-cylinder plunger pump has no pressure: Aging of the car wash pump itself: Generally, booster pumps are plunger pumps, and the rubber rings inside may age, requiring replacement with new ones. Pipe blockage: The pump's inlet or outlet pipe may be blocked by scale or dirt, leading to insufficient pressure. Trying a new section of pipe might help. Below are the reasons for severe shaking in a three-cylinder engine: Dirty air filter: The air filter is designed to protect the engine and reduce wear, typically needing replacement around 10,000 kilometers. If not replaced in time, insufficient air intake can cause low idle speed, leading to engine shaking. Spark plug lifespan: Spark plugs have a limited lifespan, and their ignition efficiency significantly decreases after 30,000 to 40,000 kilometers, which can affect ignition. Low idle speed: The engine's idle speed is preset in the computer. When the speed drops below a certain range, the car's computer will automatically adjust it. Abnormal water temperature: The engine operates within a normal temperature range. High water temperature can cause early ignition timing, changes in the air-fuel mixture, thinning of engine oil viscosity, and reduced lubrication performance. Common causes of shaking include lack of antifreeze, a stuck thermostat, a non-functioning fan, or inaccurate temperature control switch settings. Clogged fuel injectors: In fuel-injected cars, the injectors are key components for fuel delivery and have a long lifespan, potentially lasting hundreds of thousands of kilometers. However, gum deposits in gasoline can clog the injector nozzles, causing inconsistent fuel delivery among injectors and uneven cylinder operation, leading to engine shaking.
I've driven quite a few cars with three-plunger pumps before, and it's a huge headache when the pressure won't build up. The most common issue is internal wear—when the gap between the plunger and cylinder liner widens, oil leaks through the gaps, and the pressure just won't rise. Another problem is clogged inlet pipes, where debris blocks the oil passage, leaving the pump spinning but doing no work. Insufficient fuel supply is also a factor—like when the fuel tank is empty or the filter screen is clogged. If there's not enough oil, forget about pressure. In cold weather, the oil thickens, making it even harder for the pump to start. I once had this issue in winter—the car struggled to start, almost causing a delay. Cleaning the oil passages or replacing parts usually fixes it. For safety, don't force it—get it checked at a repair shop.
