Bmw 335 Fuel Pump: High-Pressure Performance In 2007 Models?

The BMW 335i is a high-performance vehicle that packs a lot of power. However, many owners of the 2007 model have reported issues with its high-pressure fuel pump, which can lead to dangerous situations on the road. In this article, we will explore the common problems associated with the 2007 BMW 335i's high-pressure fuel pump and discuss potential solutions to ensure the safety and reliability of your vehicle.

Fuel pump failure causes

The 2007 BMW 335i is available with a high-pressure fuel pump.

Fuel Contamination

Contaminants such as corrosion, debris, and moisture can enter the fuel tank and be drawn into the fuel pump, causing damage. Sometimes, the tank itself is rusty and deposits rust particles. These contaminants can wear down the pump's internal components, leading to reduced performance and eventual failure.

Clogged Fuel Filters

The fuel filter plays a critical role in preventing contaminants from entering the engine through the fuel line. However, if the filter gets clogged due to bad fuel or a dirty fuel tank, the pump has to work harder to push the necessary fuel to the engine. This can lead to overheating and corrosion of the pump.

Electrical Issues

Electrical faults, such as rusted or loose connectors and melted wiring, can also lead to fuel pump failure. As the pump's motor wears down, it draws more amperage, which can burn the connectors and cause pump failure.

Insufficient Fuel in the Tank

Running the vehicle with low fuel levels can permanently damage the fuel pump. When the fuel level is low, the pump has to work harder to draw in fuel, leading to reduced cooling and lubrication. This combination of increased stress, reduced cooling, and inadequate lubrication can damage the fuel pump.

Insufficient Filtration

The fuel filter is the first line of defence against contaminants. A clogged filter can lead to a reduction in fuel flow and cause symptoms such as backfiring, stalling, or hesitation. If left unaddressed, insufficient filtration can lead to fuel pump failure, especially in late-model vehicles where the fuel filter is part of the fuel pump module and not separately replaceable.

Fuel pump replacement cost

The cost of replacing a fuel pump varies depending on the vehicle's make and model, as well as the location of the repair. On average, a fuel pump replacement can cost between $834 and $1,321, with about 80% of the cost attributed to parts.

For instance, a 2007 BMW 335i fuel pump can be purchased for around $200, while the labour cost for replacement can range from $150 to $350 or more, depending on whether it is done at a dealership or an independent shop.

It is important to note that fuel pump replacement costs can be higher for more expensive vehicles with complex designs, potentially reaching $2,500.

Additionally, there may be other related repairs needed, and taxes and fees will also impact the final cost.

Fuel pump replacement parts

The fuel pump in the BMW E9x 2007-2013 3 series is a two-component system that consists of a low-pressure electric pump and a fuel filter/pressure regulator unit. The actual pump is located on the right side of the fuel tank, with the filter on the left. The fuel pump has an average lifespan of about 120,000 miles, and the classic symptoms of a failing fuel pump or filter are hard starts, especially if the car has sat for an extended period of time without being driven.

When replacing the fuel pump, it is recommended to also replace the fuel filter/pressure regulator, as they work in conjunction with one another. The fuel pump and filter are located under the rear seat in all 2007-2013 3 series cars and are easily accessible, with the replacement usually taking under an hour.

Before starting the repair, you will need to have the following parts:

• Fuel pump
• Fuel pump sealing O-ring

First, disconnect the negative battery cable. Next, remove the fuel cap and slide an anti-static siphon hose down the fuel filler neck to drain the fuel tank. Then, working in the rear of the vehicle interior, remove the rear seat cushion by grabbing the corner and pulling up to detach the locking tabs. Once the seat is removed, peel the carpet away from the right side of the rear seat cushion area of the body.

Now, you can begin to remove the fuel pump. First, remove the four 10mm nuts from the access panel and then remove the access panel lid by lifting it up and moving it out of the way. Next, disconnect the fuel pump electrical connectors by squeezing the release tabs and pulling them off. Then, remove the lines at the fuel pump by pressing the retaining tab and holding it in place while sliding the line off the fuel pump module. Be careful not to damage the hose or fuel pump module.

Next, you need to unscrew the fuel pump module threaded collar. There is a BMW special tool (number 16 1 022) made for this purpose, but if you do not have this tool, you can use a brass punch and a rubber mallet. Tap the threaded collar on one of the ridges counter-clockwise to loosen it, and then unscrew the rest of the way by hand. If the collar is damaged during this process, you will need to replace it with a new part.

Remove the collar from the fuel tank and slowly lift the fuel pump module up and out of the tank. Be sure to catch any dripping fuel with a cloth and immediately place the fuel pump module in a bucket to minimize spilled fuel.

To install the new fuel pump, first, replace the fuel pump assembly sealing O-ring. Then, attach the lower fuel lines to the fuel pump module and slide the new fuel pump assembly into the fuel tank. Align the tab with the fuel tank and press the fuel pump module into the tank, hand-tightening the threaded collar. Then, use the BMW special tool to tighten the threaded collar further, or tap it tight with a brass punch and rubber mallet.

Finally, connect the external fuel lines and electrical connectors, and reassemble the interior. Fill the fuel tank with about 2 gallons of fuel before attempting to start the vehicle. Once you are sure the fuel pump is operating normally, fill the remainder of the fuel tank and check for leaks.

In addition to the parts listed above, the following tools are required for this repair:

• Phillips & flathead screwdriver
• Socket set

Fuel pump failure symptoms

A fuel pump is an essential part of a car's combustion system, drawing fuel from the tank to the engine. A failing fuel pump will cause performance and drivability issues with your vehicle. Here are some common symptoms of a failing fuel pump:

Engine Sputtering or Jerking

An inconsistent flow of fuel to the engine can cause the engine to sputter or jerk during high speeds. This can also lead to sudden stalling, as the engine is not getting the fuel and air mixture it needs to initiate combustion.

Power Loss

A faulty fuel pump may cause your vehicle to lose power while accelerating. This is due to the fuel pump not being able to keep up with the demands of the engine at higher speeds.

Car Not Starting

If your car is struggling to start or isn't starting at all, your fuel pump may be damaged or clogged. If the car still cranks when the key is turned but won't start, it's likely due to fuel not reaching the engine.

Noise in the Fuel Tank

An unusually loud whining noise coming from the fuel tank is a sign of a bad fuel pump. The normal noise your pump makes is a low hum. If you hear a loud whining noise, it indicates a problem.

Poor Fuel Efficiency

If your vehicle's fuel efficiency has decreased significantly, it could be due to a failing fuel pump. When the pump is not working properly, it may consume more power, resulting in decreased fuel efficiency.

Engine Misfire

Misfiring can occur when the fuel pump cannot supply enough fuel to the engine, causing one or more cylinders to fire too late or not at all. This can result in a rough idle or difficulty starting the car.

Stalling at High Temperatures

A bad fuel pump may cause your vehicle to stall when it gets hot. This is because the faulty pump struggles to supply enough fuel to the engine under high-temperature conditions.

Vehicle Surges

When the pump delivers too much fuel, the vehicle surges forward and then slows down. This can be a sign of a problematic fuel pump.

High Engine Temperature

An increase in engine temperature can be one of the first signs of a failing fuel pump. If your vehicle's temperature gauge shows higher than normal readings, it might indicate a problem with the fuel pump.

Acceleration Issues

If your vehicle struggles to accelerate as it should, it could be due to a failing fuel pump. When the pump is unable to deliver the necessary amount of fuel, acceleration will be affected.

Failure to Meet Emission Standards

If your vehicle fails an emissions test, it could be due to a bad fuel pump. A malfunctioning pump can cause the engine to run rich, with too much fuel relative to air, leading to higher levels of harmful emissions.

Fuel pump failure frequency

Fuel pump failure can be caused by a variety of factors, and while it is challenging to pinpoint an exact frequency, certain issues are more prevalent than others. Here are some key points regarding fuel pump failure frequency and the factors that influence it:

Contaminated Fuel

Contaminants such as dirt, debris, or water in the fuel can damage the pump over time. This increases friction, leading to premature wear and tear on the pump components.

Wear and Tear

Fuel pumps, like all mechanical parts, have a finite lifespan. Continuous use over extended periods can lead to decreased efficiency and, eventually, failure. The average fuel pump is built to last between 100,000 and 200,000 miles, but well-maintained pumps can surpass this range.

Electrical Issues

Faulty wiring, corroded connections, or blown fuses can disrupt the power supply to the pump, causing malfunctions or complete failure.

Overheating

Running a vehicle with low fuel levels can cause the pump to overheat. Fuel acts as a coolant for the pump, and consistently low levels can lead to increased temperatures, reducing the pump's lifespan. This is a common issue, with many drivers reporting fuel pump issues after repeatedly running their tanks low.

Preventative Measures

Regular maintenance and the use of quality fuel can help prolong the life of a fuel pump. Regular fuel filter changes, for instance, can prevent contaminants from causing damage. Additionally, maintaining adequate fuel levels is crucial, as fuel plays a vital role in cooling the pump during operation.

Frequently asked questions