How to replace the fuel filter on a TDI VW or Audi diesel

Changing the fuel filter on VAG TDI diesel engines is not as easy as it may seem. Firstly, it is important to know when to change the fuel filter, and secondly, you need to choose the right filter for replacement, and there may be several of them. Thirdly, it is highly advisable to pump the power system with an OBD II scanner during replacement.

When to change, tools for replacing the VW TDI fuel filter

Turbo-diesel engines of the TDI (Turbodiesel Direct Injection) family are rightly considered one of the most efficient modern diesel engines. They are installed on many models of Volkswagen (Passat, Jetta, Bora, Caddy, Golf, Polo, Sharan), Audi (A3, A4, A6), Skoda, Seat and even Ford Galaxy, Volvo 840, Mitsubishi Grandis, Lancer and many other VAG models and more.

Regardless of the engine size and its index (EA827, EA188, CBAA, BLS, CFGC, etc.), the fuel filter is changed using the same technology. There are some differences in spare parts and features of the fuel system, but this does not affect the essence of the matter too much.

According to the VAG regulations, the fuel filter in TDI diesel engines should be changed every 30,000 km. However, if you refuel not at a trusted gas station, but who knows where, then the regulation should be reduced to 20 thousand km. The quality of diesel fuel at gas stations is not always the same.

In addition to the filter element itself, the filter housing cover seal must also be replaced. In addition, the official VAG technology card requires the replacement of five screws for the cover. Reputable spare parts manufacturers, by the way, sell the filter complete with screws and a gasket.

In general, you will need a fairly simple list of tools to do the job:

However, if it is not possible to connect to a scanner, in our case, sometimes you can do without it.

How to choose a VW TDI fuel filter, types of filters

The principle of operation of the fuel purification system is the same on all VAG TDI turbodiesel engines. However, the filter configuration may differ slightly depending on engine size and year of manufacture.

An important clarification is that Mann and Meyle supply fuel filters to VAG assembly lines, so you should not worry about the “non-original” origin of the filter from these manufacturers, as they are mostly original, just without the Audi, Seat, Skoda or Volkswagen logo.

For example, on the left is a filter Mann PU 936/2, the filter on the right is an original filter VW/Audi 1k0 127 177 A (interchangeable with 1k0 127 434 A).

After 2009, TDI engines use 2 different fuel filters. 2009-2010 Jetta TDI’s built until about 8/2010 used the wide-mouth, 2-hole filters (1k0127434 or 1k0127434A).

2010 VW Jetta TDI built after 9/2010 and 2010 Golf TDI should use the 1-hole narrow-mouth filter 1k0127434b. The difference in the part number is the absence of a suffix, an “a” or a “b” suffix.

The difference is in the details – narrow neck with 1 hole (B filter) or wide neck with 2 holes (filter without suffix and A). They use different housings, and the wide-mouth filter with 2 holes is taller.

The difference in filters was due to changes in supply and availability of parts during production. VW would switch from one type of filter to another, then return to the first. During transitional periods, the part that will be installed on a particular car can be as random as the guy on the assembly line taking something from the left or right bin.

Although the engine and basic chassis of the 2010 Audi A3 TDI are the same as those of the Golf and Jetta TDI, it can also be installed in a different body.

For the engines of the 2009 VW Jetta sedan and Audi A3 TDI, the code name CBEA is used. All others have CJAA engines. Fuel filters do not depend on the type of turbo diesel engine.

If the fuel filter housing is shown in photo #1 or #2, it is a wide-mouth filter with 2 holes (they are interchangeable). If the filter housing is shown in photo #3, it is a narrow neck filter with 1 hole. Filter #3 is shorter than the others, so it is not interchangeable.

Filter No. 1 – catalog number of the filter element, VW 1k0 127 434 or 1k0 127 177. The instruction manual says that a little fuel should drain from the drain hole with a Torx screw thread, but most likely there will be no water there.

Filter #2: catalog number VW 1k0 127 434 A or 1k0 127 177 A.

If the fuel filter housing is shown in photo #3, the filter element number is VW 1k0 127 434 B or 1k0 127 177 B..

How to replace the fuel filter on VW/Audi TDI engines

Changing the fuel filter on any TDI engine is usually a simple matter. You do not even need to remove the fuel hoses from the fittings on the housing cover. If the cover has a condensation drain plug, you can use this before removing the cover screws.

In general, the procedure for replacing the fuel filter of VAG turbocharged diesel engines is as follows.

If there is a condensate drain plug (1), unscrew it and drain the condensate. But usually, in 90% of cases, there is no condensation there. Because of this, later designers abandoned this plug.

But if there is a plug, after pumping it out, replace its seal and tighten it with a force of 3 N∙m.

Loosen the screws securing the filter housing cover by two turns in a crosswise pattern.

Loosen the screws completely and pry the housing cover with a flathead screwdriver.

Carefully remove the cover together with the hoses and move it aside so that it does not get in the way.

Remove the filter element from the housing.

Pump out the remaining fuel from the housing and wipe it dry with a clean cloth.

Remove the old seals of the housing cover.

Wipe off any dirt on the lid and install a new seal.

Set a new filter element.

Replace the cover and tighten the screws crosswise with a torque of 5 N∙m.

Now you need to remove air from the power system and fill the filter housing with diesel fuel. To do this, you usually use a diagnostic scanner and programmatically start the fuel pump.

This is done in four steps, as shown in the photo below: select the engine control module in the VCDS program, select the basic module settings, then select the activation of the fuel pump. Start the pump using the button in the fourth photo for 40-70 seconds, and then turn off the fuel module programmatically.

Check the fuel filter housing for leaks, wipe it dry and start the engine. Make sure that the engine is running normally and that the filter is tight.