DIY bmw fuel pump repair

In detail: do-it-yourself bmw fuel pump repair from a real master for the site my.housecope.com.

We will show you how to replace a fuel pump in a BMW E39 car with your own hands. It is quite simple to do this, the main thing is to observe safety precautions. We take out the sofa of the rear passengers, the technological hole will be on the right, unscrew the 3 screws securing the top cover with a Phillips screwdriver. Disconnect the pump power supply chip.

Video of replacing a fuel pump in a BMW E39:

Backup video instruction:

The direct functions of the car's fuel system are both storage and further supply of fuel to the timing (stands for the gas distribution system of the car), as well as its filtration. The design of the fuel supply system consists of the following set of devices:

  • Gas tank;
  • Fuel filter;
  • Gasoline pump;
  • Fuel level sensor;
  • Valve on the fuel filler cap;
  • Hoses, connecting pipes;
  • Balance tank.

Signs of damage to the fuel pump or fuel filter can be as follows, each point is a separate anticipated situation:

  1. Unable to start the car, the candles are dry. Very little or no pressure in the fuel line. No buzzing of the gasoline pump when the ignition is turned on / the starter is rotating. There are no flashes in the cylinders when rotating by the starter.
  2. Unable to start the car, dry candles. The pressure in the fuel line cannot be determined without a pressure gauge.
  3. At idle, the car works quite steadily, the candles are black. But if you press the gas pedal, the engine immediately stalls. Any attempt to move the vehicle will cause the engine to stall. The sound of the fuel pump may change.
  4. The vehicle starts up, in states of rest and movement, one can observe the following situations: in the first case, the engine picks up high revs quite quickly, but in the second case, you can observe some "twitching" at medium and high speeds. It is possible that the car does not pick up speed after reaching a certain value. The candles are usually white in such cases.
Video (click to play).

It is worth saying that the above situations do not necessarily manifest themselves in full, and there are many other signs. In any case, you need to listen to how the gas pump works. Also, monitor the quality of the fuel used, because when using low-quality hot fuel, there is a high probability of damage to the entire fuel system of the vehicle, the cost of overhaul of which is clearly greater than the difference in the price of gasoline.

The filter is located on the front of the no-tank, so the car will have to be lifted anyway.

Remember! Fuel is pressurized in the system, so be sure to be careful when removing the filter.

In general, your actions boil down to the following algorithm, which is simple to execute:

  1. We substitute a specially prepared container for draining.
  2. We unscrew one of the fastening clamps, carefully release the pressure in the system, while twisting the hose. We remove this clamp.
  3. Remove the second clamp.
  4. We remove the filter itself.

It should be noted that the new filter must be installed in a specific direction, as indicated by the arrows on the element housing. Do not forget to check the tightness, for this you only need to start the engine and inspect the connections for possible leaks.

To carry out repair work to replace the fuel pump of a BMW e34 car, of course, a new pump, a screwdriver (Phillips), a small number of metal clamps, a vacuum cleaner, pliers.

The first thing that needs to be done right away is to remove the terminals from the battery, to exclude a short circuit and ignition as a consequence is not worth it. Next, remove the carpet and spare tire in the trunk. You should see something like the one in the photo below. You should be interested in a black plug secured with five screws.

Removing the cover, we see a large amount of sand inside. The power plug secured with a metal clasp must be removed. Vacuum up any accumulated sand.

Image - DIY bmw fuel pump repair

Image - DIY bmw fuel pump repair

Now is the time to carefully remove the fuel pipes. Let me remind you once again that the gasoline in the fuel supply hose is under pressure, so be careful. For ease of reassembly, it is recommended to mark all removed hoses. In this case, screeds with certain marks were used.

After opening the gas tank, unscrew the locking ring. Now carefully pull the entire device out of the fuel tank, including the level sensor. Note that the structure is connected by two pipes to the fuel pump. With your hand inside the tank, feel for the 2 plastic clips on the pump housing. Now you can get the entire unit completely out of the fuel tank. Prepare some rags as a small amount of fuel will still remain in the pump.

Image - DIY bmw fuel pump repair

Image - DIY bmw fuel pump repair

It remains to dismantle the old pump, attach a new one, if necessary, cut off the old power contacts and solder the new ones; perform all operations in reverse order. Then turn the ignition key several times (5-6) to the second position, then back. Why do this: with each turn of the key, the fuel pump turns on for exactly 1 second, and as a result, the required pressure is restored in the fuel system, air is removed.

Fuel pump (gasoline pump).
Replacement instructions.
What is it for?
How much pressure should the fuel pump generate?
What is a check valve and what is it eaten with?
What are the types of gas pumps?
Which manufacturers should you choose?
Cost of replacing a BMW fuel pump?

Self-replacement of the BMW fuel pump. Attention! This manual is unified and fits most BMW vehicles.
This instruction is not a motivation for action and all independently performed work and their consequences are performed at your own peril and risk.
It is better to entrust the replacement of the BMW fuel pump to specialists.

The fuel tank of BMW series cars is located under the rear seat and "consists" of two halves. In the middle of the gas tank there is a recess for the propeller shaft.
There are only three elements in the gas tank itself, which sometimes require repair or replacement.
1. On the passenger side, the fuel pump itself and the fuel level sensor are located.
2. On the driver's side there is an additional fuel level sensor.
3. On the driver's side there is also a transfer pump (not always electric), it serves to equalize the fuel level in both compartments of the gas tank.
The recommended interval for replacing the BMW fuel pump is 150-200 thousand kilometers.
Masters BMWpitstop, recommend to carry out work on replacing the fuel pump with an empty tank (for example, when the fuel lamp is on).

Required tools and equipment:
- Gloves;
- Small flat screwdriver;
- Large flat screwdriver;
- Pliers;
- Clamps;
- A vacuum cleaner;
- Dry rags;
- Good mood;
- Beer;)

First of all, we must remember. The gas tank contains gasoline and highly toxic vapors. Replace in the street, summer cottage, or in a very well ventilated area.
Remember that the slightest spark can ignite gasoline vapors. Move away matches, lighters, etc.
Be sure to disconnect the battery terminals. Think about safety. Common sense comes first.

Step 2: Prepare your work environment

Move the front seats forward and create the conditions for quiet work and movement inside the cabin.
Remove the bottom of the rear sofa. As a rule, they are fastened with two clips 20 cm from the edges. Pull the seat up, first on one side, then on the other (don't be afraid to apply some force).
Release the seat belt buckles and slide the seat to the side.
The fuel pump is hidden under a dark sound-absorbing mat. Throwing it back, you will see the plugs holding the fuel pump.

The metal plugs are attached to the body with four bolts. Remove these screws and metal covers to expose the pumps and sensors.
Since the gas tank is technically on the outside of the body, it is likely that a lot of dirt has accumulated around it. Before unscrewing the stick caps, be sure to remove any dirt around it.
Use a vacuum cleaner if necessary. Do not allow dirt to get inside the gas tank.

Step 4: Remove the plastic locking ring

Each block is held in place by a large retaining ring. Unscrewing them is quite difficult, so arm yourself with a screwdriver, hammer and patience.)
Press the screwdriver into one of the lid ridges and unscrew it with gentle hammer blows. Be careful not to break the cover.

Step 5: Disconnect all connectors

Make sure the battery is disconnected and disconnect the connectors from the fuel pump unit.

Step 6: Disconnect the hoses (careful!)

This part of the job requires a lot of attention.
Remove the suction / sensor hose first. Look closely at the hose clamps and replace them with new ones if necessary.
Check the hose where the clamp is attached for scuffs and cuts.
Remove the hose carefully. Although the plastic of the pump unit is resistant to the effects of aggressive media, it can be very fragile at runs of 150,000 km (5-8 years of operation).
Use a small screwdriver to "peel" the hose off the plastic. Note that there may be fuel in the hose.
Therefore, use rags when detaching. It will be very difficult to erase the smell of gasoline soaked in the skin)

Step 7: remove and replace the fuel pump

Now that the hoses and connectors are disconnected, you can remove the retaining ring and pull out the gas pump a little. Keep in mind that a hose (suction) coming from the second part of the tank is also connected to the bottom of the fuel pump.
Using a small screwdriver, disconnect the suction hose from the bottom of the fuel pump. Pull out the fuel pump and try not to sink the suction hose, hold it.

Step 8: Replace the pump assembly

It's time to install a new fuel pump unit. Connect the suction hose to the pump until it clicks. Make sure the connection is secure.
The position of the pump during installation is also important. BMW engineers helped us with this and the pump is difficult to install incorrectly.
Some BMW models have special alignment marks that need to be aligned.
Change the gasket under the pump cover.

Step 9: Connect electrical connectors and hoses

Make sure you have correctly connected all connectors and hoses. Screw on the retaining ring. Connect the battery and turn on the ignition several times. After that, check the fuel pump cover for possible leaks.
Re-seal the pump if necessary.

Step 10: assembly and test drive

Reassemble everything in reverse order. And take a test drive.
Do not be surprised if the car does not start right away, the pump needs to pump out the air that has got there, and this may take some time.

Step 11: Open the beer)! Everything is ready! You are well done))

Image - DIY bmw fuel pump repair

Image - DIY bmw fuel pump repair


Which manufacturers should you choose?
Gas pumps from various manufacturers are used in modern cars.
Below is a list of the most common and quality manufacturers:
1. VDO-Siemens;
2. Pierburg (MS Motorservice International);
3. Bosch;
4. Walbro;
5. Magneti Marelli;
6. AIRTEX;
Cost of replacing a BMW fuel pump?
On almost all BMWs, the replacement cost starts from 2000r and is accurately calculated individually according to the car's wine code.
BMWpitstop specialists will always help you with replacing your BMW fuel pump.

The main element of the fuel system of a modern car is the fuel pump, the main function of which is to transfer fuel from the gas tank to the engine. This is one of the most capricious parts of a car, requiring constant monitoring and maintenance.Diagnostics, repair and replacement of the fuel pump can be carried out independently, without resorting to the services of a car service.

The main function of a fuel pump or a gasoline pump is to supply a certain amount of fuel under pressure to the carburetor (carburetor type motors) or to injectors (injection type motors). The fact is that the gas tank is in the back of the car, and the power unit is in the front. Therefore, fuel can flow to the engine only under a certain pressure, which is created by the pump.

The fuel pump starts supplying fuel when the engine starts. Inside the pump, due to the movements of the diaphragm, the inlet valve opens. Gasoline begins to flow, which in the next cycle of movement of the diaphragm through the exhaust valve under pressure is supplied to the engine.

On modern cars, two types of gas pumps are used - mechanical or electric... The former are used in carburetor engines, the latter in injection engines.

The mechanical pump is usually installed on the body of the gas tank, the electric one is inside the tank. Some car manufacturers use both types of pumps at once.

The mechanical fuel pump is quite large. Its main elements are:

diaphragm return spring;

When power is supplied to the gasoline pump, the lever begins repeated up and down movements. Due to these movements, the diaphragm is displaced, and gasoline enters first into the pump, and then into the engine.

This is how fuel is supplied in carburetor-type engines. Since the distance between the carburetor and the fuel pump is usually small, such devices can supply fuel even at minimal pressure.

Electric petrol pumps are small in size and simple in design. Inside the pump housing are:

diaphragm return spring;

The core of the electric pump is the core. Due to the additional valve, it reciprocates and opens the valves for the inlet and outlet of fuel. Such a pump works only at high fuel pressure in the system and heats up very much while the car is moving. For more efficient cooling, it is usually mounted in a gas tank.

Image - DIY bmw fuel pump repair

The electric fuel pump is small in size and simple in structure.

The fuel pump is powered by the power unit. At the moment the engine starts, the on-board computer signals the fuel system to supply fuel. Electricity is supplied from the engine to the fuel pump, and a small motor inside the pump creates the necessary pressure in the system. In the first few seconds after starting the car, you can hear the gas pump humming, pumping gasoline.

A certain amount of fuel enters through the inlet valve into the pump chamber, then through the outlet valve into the fuel filter. There, the fuel is cleaned of dirt and impurities and sent to the engine. The fuel pump turns off automatically, together with the engine.

In cars with an injection-type engine, the fuel pump is located inside the gas tank, and in the case of a carburetor engine, under the hood or near the gas tank. On some models, two fuel pumps are installed at once: one on the gas tank, and the other on the engine. The exact location of the pump in your car can be found in the service book or operating manual.

The technology for diagnosing, repairing and replacing a fuel pump is usually not very difficult. If there is a desire, time and a minimum set of tools, all work can be easily performed independently.

In order to remove the fuel pump, it is proposed to perform a series of sequential steps.

Locate the device on the engine that is connected to the fuel supply system.

Image - DIY bmw fuel pump repair

The fuel pump is connected to the fuel supply system

Disconnect the plug with wires from the fuel pump.

Image - DIY bmw fuel pump repair

When dismantling the fuel pump, disconnect the connector with wires and fuel supply hoses

Disconnect the fuel supply hose.

Disconnect the collet and remove the four mounting bolts.

Gently pull the fuel pump out of the socket by hooking it onto the rubber gasket.

  • Clean the device from oil, dust and dirt.