Is it time to replace the fuel pump? The fuel pump is responsible for transferring fuel from the gas tank to the vehicle’s engine. With a malfunctioning fuel pump, the engine won’t have fuel to keep the vehicle running. If this necessary component is failing, it can cause severe drivability and performance issues and has to be dealt with if you want a reliable, driveable vehicle. So how much will it cost to fix the fuel pump? As per yourmechanic.com, a complete fuel pump replacement cost at a mechanic shop can land anywhere between $532.97 and $1,187.35 depending on factors such as the vehicle’s make and model and where the vehicle is fixed.
We will explain the types of fuel pumps, the signs of a bad fuel pump, and how a good mechanic will replace the fuel pump. We will also go through fuel pump repair cost breakdown.
How Much Does a Fuel Pump Replacement Cost?
As per repairpal.com data – “The average fuel pump replacement cost is between $834 and $874 with about 80% of the cost being the cost of the parts“. You may be able to find fuel pump parts for $50. Good quality fuel pump sets can cost between $200 to $1000. Labor costs are $150-$350. More expensive vehicles with complex designs can cost $2,500 to have a fuel pump replaced.
Here is a chart from YourMechanic.com that shows the average cost of fuel pump replacement for different vehicles.
|Cars||Parts Cost||Labor Cost||Average Dealer Price|
|2015 Subaru Legacy||$373.60||$163.97||$593.97|
|2009 Chrysler Aspen||$956.23||$171.97||$1187.35|
|2012 Ford Fusion||$379.11||$179.97||$620.98|
|2006 Mercedes-Benz ML500||$471.23||$235.97||$788.35|
|2006 Lexus RX400h||$216.31||$315.96||$640.93|
Types of Fuel Pumps
Automotive fuel pumps are either mechanically or electronically operated. Modern-day vehicles that require more pressurized fuel supply than mechanical fuel pumps can deliver will have an electronically operated fuel pump or fuel module that is mounted on or in the gas tank.
Fuel pumps have various components that work together to send fuel from the gas tank, through the fuel filter, to the fuel rail, distributed into the injectors, and sprayed into each engine cylinder combustion chamber. The pump must produce a certain pressure specified by the manufacturer.
1) Mechanical Fuel Pump
Older vehicles that have a carburetor will have a mechanical fuel pump with either a diaphragm or plunger-type pump. Automobiles with engines rated under 450hp work well with them. Mechanical fuel pumps may be the more convenient and less costly of the pumps to choose from. They can be easier to access and would, in turn, have a lowered labor cost.
Mechanical fuel pumps use a pulling force to get the gasoline through the different components. They are normally mounted on the engine block with the engine’s camshaft operating the pump. The fuel is regulated with an inlet valve closing when fuel in the float bowl of the carburetor is filled and opening when more fuel is needed.
Common issues of mechanical fuel pumps include fuel leakage from the diaphragm into the crankcase, vapor lock in the pump, faulty diaphragm spring, and too low fuel pressure.
2) Electric Fuel Pump
Modern vehicles with a fuel injection system have electric fuel pumps. These pumps do not have diaphragms or plungers that pull the gasoline but instead pushes gasoline through the different components with an electric motor.
Electrical fuel pumps can be mounted inside the fuel tank on a bracket that can be accessed from an access port on top of the tank. These pumps are designed to be submerged in gasoline. External electric fuel pumps sit outside the fuel tank.
Electric fuel pumps are powered and receive instructions from the Powertrain Control Module (PCM) and Engine Control Unit (ECU). It regulates fuel with pressure regulators.
Common issues of electrical fuel pumps include wiring issues, failed pressure gauge, overheating engine, and contamination.
Symptoms of a Bad Fuel Pump
Here are warning signs that can signify your vehicle needs a fuel pump repair and other culprits that cause the same symptoms. Rule out these other causes before paying for a fuel pump replacement that you may not need.
Difficulty Starting – Your car is having a hard time starting. For a car engine to run, it simultaneously needs air, fuel, and ignition/spark/combustion. Without these three, your engine won’t run.
Other culprits – Car is not in Park, bad battery, failing starter, no spark, engine vacuum leaks, no fuel, dirty fuel filters or fuel injectors.
Starter – No engaged starter when you turn the key. You hear nothing. You might also hear cranking. If you tap the starter and it seems to help, it’s more than likely the starter. To solve, get a new starter.
Battery – Same as starter. You can clean the battery terminals to ensure a good connection and check the charge of the battery for confirmation. To solve, jump-start the battery and get a new battery.
Overheating and Stalling – Your car shuts off on its own for no obvious reason while driving or at a stop. As with starting, your car will continue to need air, fuel & ignition to continue running.
Other culprits include engine vacuum leaks, EGR valve, MAF sensor, MAP sensor, low engine compression, Spark plugs, gasoline type.
Engine vacuum leaks can be confirmed with a loud hissing sound from the engine. You can spot a leak by spraying water on the vacuum hoses, intake manifold gasket or throttle body and see any bubbles indicating a tear.
The exhaust gas recirculation (EGR) valve can also stall your vehicle. With this issue, you would also experience rough idling and misfiring.
A bad mass airflow (MAF) sensor can also create a stall and sputtering right after starting. Other symptoms will include the hesitation from the engine on idle and engine hiccups. Cleaning the airflow sensor may relieve you of these symptoms.
Low engine compression can be ruled out with a compression test and a cylinder leak down test.
Sputtering – While trying to accelerate, the engine starts sputtering. Engine sputtering sounds like humming or purring from under the hood. This happens when there is not enough fuel pressure or inconsistent amount of fuel reaching the combustion chamber. Slow acceleration may be felt, too. This is a sincere sign there is something wrong with the fuel system. The fuel system includes the pump, fuel filter and injectors.
Other causes of a sputtering engine include faulty spark plugs, vacuum or intake leak, dirty or damaged mass airflow sensor, faulty catalytic converter, and faulty oxygen sensors.
Whining Noise – If you hear a humming or whining noise from the fuel tank. Electric fuel pumps are mounted on the gas tank in more modern vehicles.
Other culprits include contaminated fuel or not enough fuel.
Low Gas Mileage – Less miles for your gas. If the relief valve in the fuel pump is not opening at the right time, your engine will be getting excess fuel and thus you will have lower fuel efficiency.
Engine Surges – the vehicle speeds up and slows down despite pushing a constant pressure on the gas pedal. You can see this surge on the tachometer will fluctuate from about 500 rpm and feel jerking motion.
There are a wide variety of issues that cause an engine surge. Common culprits include spark plugs, ignition systems, injectors, and transmission lock-up issue.
Check Engine Light – You get a warning engine light on the dashboard. The check engine light can respond to multiple engine issues. It’s best to have it checked out to know what error code it is reading.
What causes Fuel Pumps to Fail?
There are three common reasons why fuel pumps fail.
Contamination – Rust, dirt and debris can enter the gas tank from pumping gas and clog the fuel filter.
Driving regularly on a low tank of gas – While driving on an empty gas tank, the fuel pump can overheat and cause it to run dry. This stresses out the fuel pump and can cause it to malfunction.
Age – Time does not help rejuvenate anything, even fuel pumps. Over time there will be an accumulation of contamination and wear and tear. Fuel pumps can start hiccuping around 7 or 8 years old or after 100,000 miles.
How to Diagnose the Fuel Pump Yourself
Check the fuel pressure. Look up the figures for the year and model of the vehicle and connect the pressure gauge to the fuel system. First, measure the pressure with the vehicle turned on but the engine off. Then get a second pressure reading with the engine idling. For a healthy fuel pump, you should get a reading near specifications and then see a drop of 4 to 6 psi when you start the engine.
Fuel Pump Replacement Process
A good mechanic will go through a few extra procedures apart from just replacing the fuel pump. With other replacement parts, these extra charges are necessary for the new fuel pump to run efficiently.
- The mechanic will first ensure the fuel pump is actually malfunctioning.
- The mechanic will try to remove the fuel tank without lowering the fuel tank.
- If the fuel tank must be lowered to access the fuel pump, he will drain the tank first.
- Hoses, electrical connections, and the like are removed and re-connected with the new fuel pump.
- The fuel tank straps and fasteners are replaced if there is excessive corrosion.
- If an in-line external filter is present, it is replaced.
- A test run is done to ensure no leaks are present.
How to Make Your Fuel Pump Last Longer
Keep your gas tank at least a quarter full. This will cause less stress on the fuel pump. Ensure your gasoline has no impurities. Avoid getting dirt and debris in or around the gas tank opening. Less contamination equals less fuel filter blockage.