What's A High-Pressure Fuel Pump And Why Should You Care?
ShareYou probably know that your car needs a fuel pump to get fuel from the tank to the engine, but did you know that most cars have two pumps? Your fuel injection system has two separate but equally important jobs. On the low-pressure side, it needs to pump fuel from your tank to the engine. On the high-pressure side, it needs to dispense vaporized fuel into each cylinder.
The high-pressure fuel pump (HPFP) provides the pressure necessary for your fuel injectors to do their jobs. You may not be familiar with this component since the low-pressure pump typically fails on most vehicles. Unfortunately, HPFP failures are surprisingly common on certain late-model BMWs, making this a part worth caring about if you own one of these cars.
Affected Models
There's no definitive list of models affected by HPFP failures, and this part can potentially fail on any car, but N54 engines seem to suffer the most. The N54 engine is a twin-turbo straight-six that BMW used on a range of models from the mid-2000s and on. Examples include the E9x 3-series cars, including the 335is produced up until 2013.
The newer, single-turbo N55 engine found in F30 335s uses an updated model of HPFP that's less likely to fail. While these cars are less likely to suffer HPFP issues, it's still a good idea to understand the symptoms of failure and watch for potential signs that yours may be on its way out.
Common Symptoms
The HPFP provides the necessary pressure for the fuel injectors to supply an even stream to each cylinder. As a result, common symptoms are similar to those you'd see with clogged or failing fuel injectors. A weak HPFP is likely to produce uneven or inconsistent power, rough idling, hesitation, or even hard-starting conditions.
As with low-pressure fuel pump failures, your HPFP symptoms are likely to get progressively worse over time. Although you might initially experience only a minor loss in power or fuel efficiency, you may eventually find yourself unable to start your car or even stall on the side of the road.
Repair Options
The good news is that a failing HPFP is unlikely to cause damage to your engine or result in more expensive failures over time. Unfortunately, problems with the fuel pump will eventually reach a point where your car will become undrivable, potentially leading to more inconveniences and the cost of a tow.
If you believe you're experiencing early symptoms of HPFP failure, it's generally a good idea to take your car to a shop that specializes in BMW repair as soon as you can. Promptly addressing a failing HPFP will help you restore your car's performance while also allowing you to avoid a roadside breakdown.
Contact a local repair service, such as a BMW auto repair service, to learn more.