Engine knocking, or "pinging," is the bane of any engine owner's existence, and indeed a bad fuel pump can be the cause of this no-start condition. This pump is used 1) to transport the amount of fuel required by the engine away from its gas tank, and 2) to do so at high pressure. This pressure must remain within a specific range to work as intended for most modern vehicles, typically between 40 and 60 psi. A faulty fuel pump could lead to inadequate fuel supply, thus the air-fuel blend becomes too lean. The fuel is not combusted well and the mixture turns leaner resulting in engine knocking.
One of a real-world example for this can be observed through Nissan 2021 recall of more than 400,000 vehicles due to defective fuel pumps causing poor fuel delivery thereby raising engine knocking and in certain cases are leading to the engine stalling. Unfortunately, these incidents are not isolated. They drive the crucialness of a fuel pump in sustaining vehicle performance and highlight the risk of not tending to such issues. The first signs of a failing fuel pump letter can be loss of power under acceleration, poor gas mileage and—on rare occasions—an engine knock.
You can face some severe repercussions through a bad fuel pump if you leave it unchecked. Take AAA's 2020 vehicle maintenance report, for instance, which found that engine knocking from fuel delivery problems can lead to higher rates of engine wear than is normal and might even shorten an engine's life span by up to 20 or 30%. Continued knocking can eventually break pistons and damage cylinder walls — a $1,000 to $3,000 repair. On the other hand, if fuel pump problems are detected early many of those thousands can be saved and engine life preserved for much longer.
Many car owners might ask whether to change fuel pump in any way. Most fuel pumps should last well over 100,000 to 150,000 miles in most cases. If your car is knocking most times when you accelerate then it is vital to have the fuel system examined by a mechanic. As car expert Scotty Kilmer likes to put it, "Worst case scenario is you drive the thing until the engine knocks and by then it's too late."
The fuel pump under the hood is an unlikely suspect to blame when drivers allude to why they're experiencing engine knocking, he explains, as many are prone to immediately run through a mental checklist that includes everything from running low-octane fuel in a high-octane tank or - if driving an older vehicle - possibly maintaining carbon buildup on one of the pistons. Studies and industry reports show that the problem increases with newer vehicles, those where fuel delivery is closely monitored by an electronic control system.
To sum up: engine knocking can be produced by several causes, but one of the most frequent bad guys is a failing fuel pump. The pump fails to deliver adequate fuel pressure thereby unbalancing the air-fuel mixture causing combustion before the spark plug ignites – hence, knocking noises. For example, it is important our customers recognize the maintenance they need to have in their car since a damaged fuel pump can severely damage engine equipment if not corrected promptly. Visit Fuel Pump for more info on fuel pumps and how they can affect your engine.