2007 BMW 335i High Pressure Fuel Pump Replacement: The Complete Owner's Guide

If you own a 2007 BMW 335i and you're dealing with long cranking times, rough idle, loss of power under acceleration, or an engine that stalls and won't restart, the high pressure fuel pump (HPFP) is almost certainly the culprit. This is the single most common and well-documented failure point on the N54 twin-turbo engine, and every 335i owner needs to understand what it is, how to spot the warning signs, and what replacement actually involves. The good news is that this is a known, solvable problem with clear symptoms, established repair procedures, and multiple replacement options ranging from OEM to high-performance aftermarket units. This guide walks you through everything you need to know, from diagnosis to installation to cost, so you can make the right decision for your car and your budget.

Understanding the Fuel System on Your 2007 335i

The 2007 BMW 335i uses a two-stage fuel delivery system that confuses many owners when diagnosing fuel-related problems. There are actually two separate fuel pumps working together, and knowing which one is failing saves you time, money, and frustration.

The Low-Pressure Fuel Pump (LPFP) sits inside the fuel tank, under the rear seat on the passenger side. It draws fuel from the tank and delivers it to the engine at approximately 72 psi (5 bar). This electric pump runs whenever the engine is running, and it also primes the system briefly when you open the driver's door or press the start button. On early production 2007 cars, the LPFP is a known weak point, and a failing LPFP produces symptoms similar to a clogged fuel filter: sputtering under load, hard starts, and eventually a no-start condition.

The High-Pressure Fuel Pump (HPFP) is the component this guide focuses on. It's mounted directly on the engine, near the intake manifold, and is driven mechanically by the camshaft. Its job is to take the low-pressure fuel from the tank pump and compress it to extreme pressures, up to 2,000 psi or more, so that it can be injected directly into the combustion chambers. The HPFP on the 2007–2010 N54 engines is notoriously problematic. The failure rate was so high that BMW issued an extended warranty covering this part for 10 years or 120,000 miles, and many owners went through multiple HPFP replacements under that coverage.

These two pumps work together in a precise sequence. When you turn the key, the LPFP primes the system for a few seconds. If the LPFP is weak, the HPFP can't build enough pressure to start the engine, resulting in extended cranking. Once the engine is running, the HPFP must maintain very high pressure at all times, especially under boost. If either pump loses pressure, the engine management system will throw a fault code, typically P0087 for low fuel rail pressure or 29F2 for high-pressure system issues, and may put the car into limp mode with reduced power.

The Most Common Symptoms of a Failing HPFP

The symptoms of a failing HPFP overlap significantly with LPFP failure, but there are some classic signs that point directly to the high-pressure unit. Recognizing these early can save you from being stranded and from overpaying at a shop.

1. Long cranking time before the engine starts. This is the classic HPFP symptom on the N54 engine. A healthy 335i should fire up within one to two seconds of cranking. If you find yourself holding the key for five, ten, or even fifteen seconds before the engine catches, the HPFP is losing residual pressure when the car is off. Over time, this gets worse until the engine won't start at all. This symptom is so well-known among BMW enthusiasts that it has its own acronym on forums: "long crank."

2. Rough idle and misfires. If the fuel pressure is unstable at idle, the engine will run unevenly, shake, or feel like it's about to stall. You may also see misfire codes for cylinders that are being starved of fuel. The piezo injectors on the N54 require very precise fuel pressure to atomize fuel correctly, and when pressure fluctuates, combustion becomes inconsistent.

3. Loss of power under acceleration or in boost. When you step on the gas and the turbos spool up, the engine demands significantly more fuel. A failing HPFP can't keep up with the demand, resulting in hesitation, stumbling, or a dramatic loss of power. In severe cases, the car will enter limp mode with a half-engine light on the dash.

4. Stalling and no-restart conditions. Complete engine stalls where the car refuses to restart are often a sign of LPFP failure rather than HPFP failure, but the two are closely related. A weak LPFP can't feed the HPFP enough fuel, causing the same symptoms. If your car stalls and won't restart, the problem could be either pump, and proper diagnosis is essential.

5. Fuel pressure fault codes. The engine management system is designed to detect fuel pressure issues. Common codes include 29F2 (fuel high-pressure system), 29F1, and 29DC. If you scan your car and see these codes, the HPFP is very likely the problem.

6. A whining noise from the rear of the vehicle. Some owners report a distinct whining sound coming from the fuel tank area when the pump is struggling. This is more commonly associated with the LPFP, but it can also indicate that the HPFP is demanding more fuel than the LPFP can supply.

The HPFP History and BMW's Response

The HPFP failure issue on the 2007–2010 335i was so widespread that it drew the attention of the National Highway Traffic Safety Administration (NHTSA). The agency opened an investigation in April 2008 after receiving complaints of stalling incidents in the subject vehicles due to HPFP failure.

The NHTSA noted that the 2007 335i is equipped with a high-precision fuel injection system that includes a high-pressure fuel pump driven by the oil pump chain drive assembly, which can achieve a maximum programmed fuel pressure of 200 bar. The investigation received multiple owner complaints, including accounts of sudden engine power loss while driving on the freeway, reduced power on subsequent starts, and eventual failure on every start.

In response to the widespread problem, BMW extended the warranty on the HPFP to 10 years or 120,000 miles. This was a significant move that covered many owners who would otherwise have faced expensive out-of-pocket repairs. However, that extended warranty has now expired for most vehicles, meaning current owners are responsible for the cost of replacement.

The latest version of the HPFP carries part number 13517616170. This is the most recent superseded version, and it's generally considered more reliable than the earlier versions. When replacing your HPFP, it's important to avoid older pumps with superseded part numbers, as these may have the same reliability issues as the original equipment.

Replacing the High Pressure Fuel Pump: What You Need to Know

Replacing the HPFP on a 2007 335i is a job that can be done by a competent DIY mechanic, but it's rated 3 out of 5 for difficulty on most scales. The pump is located on the side of the engine, typically under the intake manifold, which requires disassembling several engine components to gain access. The key danger is the extremely high pressure in the fuel lines, even when the engine is off. The system must be properly depressurized before attempting to disconnect any lines.

Tools you'll need: The replacement procedure requires a specific set of tools. According to a detailed DIY guide, you'll need an 8mm nut driver or socket, a flathead screwdriver, a 6mm nut driver, a 5mm Allen wrench, a 10mm socket with a 4-5 inch extension, a 17mm open-ended wrench, an 11mm socket with extension, an E12 reverse Torx socket, a Torx T-30 socket or wrench, and a 5mm Allen wrench cut down to about 3.5 inches for tight spaces. You'll also need a detach ratchet wrench and a standard ratchet wrench.

Step-by-step overview:

1. Disconnect the battery. This is very important and should not be overlooked. Anytime you're working with fuel, the last thing you want is any opportunity for a spark. The battery is located in the trunk behind the passenger side fender. Remove the access panel, loosen the negative battery terminal with a 10mm socket, and place the wire away from any metal.

2. Remove the cabin air cleaner and cowl. There are six 8mm screws that hold down the cabin air cleaner. Once removed, you'll need to take off the two access panel covers on either side of the cowl. The driver's side is trickier because there's a sensor that must be disconnected from its base. Use a pick or thin object to depress the lock pin and rotate it so it slides out of its housing. Then pull up on the two clips that secure it to the cowl.

3. Gain access to the HPFP. The pump is located on the side of the engine, near the firewall and the turbocharger. It's mounted directly onto the aluminum cylinder head. Accessing it requires patience and a methodical approach, often involving the removal of nearby intake components or even the upper engine mount to gain sufficient leverage. The pump is driven by a specialized shaft connected to the camshaft, ensuring its operation is perfectly synchronized with the engine's cycle.

4. Depressurize the fuel system. This is critical for safety. The high-pressure lines contain fuel at up to 2,000 psi or more, and the system must be properly depressurized before you disconnect anything. The procedure typically involves removing the fuel pump fuse or relay and running the engine until it stalls, then cranking it a few more times to relieve residual pressure.

5. Remove the old pump and install the new one. Carefully disconnect the fuel lines, remove the mounting bolts, and pull the old pump out. Clean the mounting surface and connection points thoroughly before installing the new pump. When re-installing, it's essential to properly bleed the fuel system, or you'll face difficult startups or air in the lines.

6. Reassemble everything and test. Once the new pump is installed, reconnect everything in reverse order. Reconnect the battery, then prime the fuel system by pressing the start button with your foot off the brake. The system should prime to about 70 psi. Then start the engine and check for any fuel leaks. If the car starts quickly and runs smoothly, the replacement was successful.[^- 4]

The job can be done in about 3 hours by an experienced mechanic. If you're doing it yourself, budget for a full day, especially if it's your first time working on this system. There are many variables that can affect the procedure, including model year differences, the presence of non-OEM parts, and modifications that may have been made to the vehicle.

Cost of Replacement: Parts and Labor

The cost of replacing the HPFP on a 2007 335i varies significantly depending on whether you choose OEM, aftermarket, or used parts, and whether you do the work yourself or hire a professional. Here's what you can expect to pay.

New OEM HPFP: Expect to pay between $950 and $1,600 for a brand-new OEM pump. The latest part number is 13517616170, and this is the version you want to install. Several online parts retailers list this pump at around $1,210. This is the safest option in terms of reliability and guaranteed compatibility.

New aftermarket HPFP: These typically cost between $450 and $700, which is significantly less than OEM. When choosing an aftermarket pump, it's important to select one from a reputable brand. A high-quality aftermarket pump can be a cost-effective alternative, but a low-quality pump can lead to premature failure and further damage.

Used OEM HPFP: These can be found for $150 to $400, but they come with high risk. The HPFP has no reliable physical inspection method, and failure is internal. A used pump of unknown history is a gamble. If you're considering a used pump, save yourself the risk and skip it.

Shop labor: Labor costs range from $230 to $340 for professional installation. Some repair shops quote the total job at $1,896 to $2,100 including parts, with labor estimated at $146 to $215 and parts at $1,750 to $1,885. This range doesn't include taxes and fees, and it doesn't factor in your geographic location.

For most owners, a new or professionally remanufactured unit from a reputable supplier is a much safer investment than a used part. The labor to replace the pump is significant, and you don't want to do the job twice. Spending a little more upfront for a quality pump saves you money in the long run.

Choosing the Right Replacement Pump

When it comes time to replace your HPFP, you have several options. Here's how to make the right choice.

1. OEM pumps. OEM pumps are manufactured by BMW and are engineered to match the original specifications exactly. They offer peace of mind regarding fit and longevity. The latest version, part number 13517616170, is the most reliable OEM option. It's compatible with previous part numbers, including 13517585655, 13517592881, 13517594943, 13517596123, 13517613933, 13537537320, 13517616446, and 13517616194.

2. Aftermarket pumps. Reputable aftermarket brands can be a cost-effective alternative to OEM. The key is to choose a known brand with a good reputation. Some aftermarket pumps offer improved performance characteristics, which can be beneficial if your car has a tune or other performance modifications. However, keep in mind that the pump is the heart of the fuel delivery system, and a cheap pump can cause serious problems.

3. Remanufactured units. Professionally remanufactured units from reputable suppliers can offer a middle ground between cost and reliability. These should be inspected and tested to meet OEM specifications. This can be a good option if you're on a budget but don't want to risk a used pump of unknown history.

4. The KEMSO option. If you're looking for a high-performance replacement that won't break the bank, KEMSO offers fuel pumps designed as OEM replacements with performance-grade construction. KEMSO fuel pumps are built to meet or exceed original equipment specifications, and they come with a lifetime warranty. This makes them an attractive option for owners who want reliability and peace of mind without paying premium OEM prices. You can browse their full lineup at https://www.kemsoracing.com/. KEMSO products are available for a wide range of vehicles, from BMW motorcycles to Kawasaki jet skis to Subaru Imprezas, and they focus on delivering high-performance, durable fuel delivery solutions.

When choosing a replacement pump, make sure to verify the part number matches your vehicle. If you're not sure, send the OE number together with your vehicle model, chassis, or VIN to confirm compatibility. The HPFP for the 2007 335i mounts directly to the engine and plays a crucial role in maintaining pressure for fuel injection. A reliable HPFP is vital for performance and efficiency, as it directly impacts fuel flow to the engine.

Diagnosis: Making Sure the HPFP Is Actually the Problem

Before you spend money on a new HPFP, it's essential to confirm that this is actually the source of your problem. Fuel system failures can have multiple causes, and misdiagnosis is common. Here's how to properly diagnose your 335i.

Check fault codes. The first step is to scan the engine computer for stored diagnostic trouble codes. Codes like 29F2, 29F1, and 29DC are classic indicators of a failing HPFP. A misfire code for a specific cylinder may also point to a fuel delivery problem, but it could also be caused by spark plugs, ignition coils, or fuel injectors.

Test fuel pressure. The most definitive test is to measure the actual fuel pressure at the rail using a mechanical gauge. Connect the gauge to the Schrader valve on the low-pressure rail in the engine compartment, then press the start button with your foot off the brake so you don't start the engine. The system should prime to 70 psi. Then turn off the car and watch the gauge. Pressure should stay at about 70 psi for 20 minutes without dropping. If it spikes to 70 psi when you press the button but doesn't hold the pressure when the pump is off, you're not getting the flow rate you need to keep the car going. This points to the fuel pressure regulator rather than the HPFP itself.

Check the fuel pressure regulator. On the 2007 335i, the fuel pump sits on the passenger side of the car. On the left side of the tank, there's another access port that houses the fuel pressure regulator. The regulator is connected to the fuel pump by hoses inside the fuel tank. These hoses have a tendency to slide off, and if they do, fuel just circulates back to the tank and line pressure drops. Before you order a new HPFP, open the fuel pump access hatch and inspect the hoses. If they're still connected, then you may need to replace the pressure regulator rather than the high-pressure pump.

Check the LPFP control module. There are three points that commonly fail: the EKPS (fuel pump control module), the fuel pressure regulator, and the fuel pump. The low-pressure pumps themselves rarely fail. The proper way to test the system is to use the ISTA or INPA software with the interface cable, which is available for about $30. With these programs, you can see the pump run and test out the fuel pump control module. If you've tested everything else and the LPFP is receiving low voltage, the control module may be the problem.

Visual inspection. A visual inspection for fuel leaks around the pump and its fittings is essential. Look for signs of fuel seepage, which can indicate a failing pump seal or a cracked housing. The pump is a robust piece of engineering, but it operates under extreme stress, and physical damage is possible.

Other Common Issues on the 2007 335i

While the HPFP is the most infamous problem on the 2007 335i, it's not the only one. Understanding the other common issues on this car helps you put fuel system problems in context and avoid misdiagnosis.

Fuel injector problems. The piezoelectric fuel injectors on the N54 engine are prone to leaking or clogging, which can cause misfires and fuel dilution in the engine oil. Symptoms include rough idle, especially on cold starts, a fuel smell, and a rich running condition. The updated index 12 injectors are the current replacement, and they typically cost $250 to $400 per injector, often replaced in sets.

Turbo wastegate rattle. The stock N54 turbos often develop wastegate rattle or even complete turbo failure over time. This presents as a rattling sound on deceleration, loss of boost, and underboost codes. Replacing the turbos costs $2,000 to $3,500 for parts and labor, and the job is substantial.

Water pump and thermostat failure. The electric water pump is another well-known failure point on the N54. When it dies, the engine overheats quickly, and the car should be stopped immediately. Symptoms include overheating, the cooling fan running at full speed, and warning lights on the dash. Replacement costs $800 to $1,200, and it's recommended to replace the thermostat at the same time.

Carbon buildup on intake valves. Because the N54 uses direct injection, the intake valves aren't cleaned by fuel spray, and carbon deposits accumulate over time. This causes loss of power, poor throttle response, misfires, and rough idle. The fix is walnut blasting, which costs $400 to $700 and should be done every 50,000 to 60,000 miles.

Oil filter housing gasket leaks. The OFHG is a notorious leak point on the N54. If left unchecked, oil can reach the serpentine belt and cause serious damage. Symptoms include a visible oil leak at the front driver side of the engine and low oil warnings. Replacement costs $300 to $600.

Ignition coil and spark plug failure. Coils and plugs degrade with age and turbo heat, often causing misfires under boost. Symptoms include misfires, poor fuel economy, and the check engine light. BMW recommends replacing all coils and plugs every 50,000 to 60,000 miles, and this costs $200 to $400.

Battery and IBS sensor problems. The Intelligent Battery Sensor can shut down electrical systems or cause no-start conditions. Symptoms include electrical glitches, random warning lights, and hard starts. The fix is to replace the battery and IBS sensor and register the new battery, which costs $250 to $400.

Tips for Preventing Future Fuel Pump Failures

While HPFP failure on the 2007 335i is largely a design issue that you can't completely prevent, there are steps you can take to maximize the life of the replacement pump and avoid other fuel system problems.

1. Use quality fuel. Always use premium fuel with a minimum octane rating of 91. Low-quality fuel can leave deposits and cause the pump to work harder than necessary.

2. Don't let the tank run low. Running the fuel tank low on a regular basis puts additional strain on the in-tank LPFP, which feeds the HPFP. Repeatedly running the tank to empty can shorten the lifespan of both pumps.

3. Change the oil regularly. The N54 is hard on oil, and contaminated oil can affect fuel dilution and overall engine health. Change the oil every 5,000 miles using high-quality synthetic oil.

4. Replace related components proactively. When you replace the HPFP, consider replacing the fuel filter, spark plugs, and ignition coils if they're due. This ensures you don't have to go back into the engine bay again soon.

5. Use updated parts. When replacing the HPFP, make sure you get the latest version, part number 13517616170. Avoid older, superseded part numbers that may have the same reliability issues as the original equipment. If you're replacing injectors, use the updated index 12 units.

6. Get a proper diagnostic scan. Invest in a BMW diagnostic tool like ISTA or INPA, or find a shop that uses them. This helps you catch fuel system issues before they become catastrophic failures.

7. Consider a KEMSO fuel pump. If you want a high-performance replacement that comes with a lifetime warranty, KEMSO provides OEM replacement pumps built with performance-grade materials. Their products are designed to handle the demands of high-performance engines and come backed by a warranty that gives you peace of mind. Visit https://www.kemsoracing.com/ to see their full range of fuel pumps and other performance parts.

Final Thoughts

The 2007 BMW 335i is a driver's car through and through. The N54 twin-turbo engine delivers impressive performance and a driving experience that has earned it a dedicated following. But the HPFP is a known weak point, and if you own one of these cars, fuel pump failure is a matter of when, not if. The key is to recognize the warning signs early, get a proper diagnosis, and choose a quality replacement pump.

Whether you decide to tackle the replacement yourself or hire a professional, the information in this guide gives you the knowledge you need to make informed decisions. The cost of replacement can range from around $700 for a DIY job with an aftermarket pump to $2,100 or more for a professional installation with an OEM pump. By understanding the symptoms, the diagnosis process, and the replacement options, you can save yourself money and avoid being stranded.

If you're looking for a high-performance replacement option with lifetime warranty coverage, be sure to check out KEMSO fuel pumps. They offer OEM replacement pumps designed for high performance and reliability at competitive prices. Visit https://www.kemsoracing.com/ to learn more and find the right fuel pump for your 2007 BMW 335i.