[chittychittybangbang]

Comment I received regarding the 2009 fuel filter change procedure. http://www.myturbodiesel.com/1000q_how_to/a5/09Ffilter.htm Can anyone verify?

chittychittybangbang,
I have yet to find a 2009 or 2010 (CBEA or CJAA engine) that the fuel pump cycles on for a second or two when the key is cycled.

It seems everyone assumes that they do, similar to the earlier PD engines. I also made this assumption, and when I could not get fuel to squirt out while cycling the key, I initially assumed I had a failed fuel pump. Not so. Both of the electric fuel pumps run when cycled with VCDS.

But the fuel pumps do NOT cycle on when the key is first turned on, on any that I have tried, or for other folks who have done a definitive test.

A definitive test is to put the fuel filter inlet hose into a jar and cycle the key.

 

[Stefan2006]

Which one is the feed line? It doesn't say in the writeup.

 

[chittychittybangbang]

Pic added. DanG144 figured out the routing

 

[chittychittybangbang]

Well I tested this today and I can confirm that the common rail engine does not run the fuel pump when you turn the key to ON but not start. I removed the fuel line coming from the fuel tank and had the key ON but not a drop of fuel came out. Will edit the how to change the fuel filter article for 2009+ Jetta and Golf TDI to reflect this.

 

[chittychittybangbang]

Well another fact found. VW must have had lots of old fuel filter canisters left over because they have started using the "B" style 1 hole narrow mouth filters again on 2010 VW Jetta TDI. This means that during the production of the mk5 Jetta, they switched from one style, to the next, back to the first, and finally brought back the other one for 2010.

Here is proof from a 2010 Jetta. I also added some screenshots of using VCDS to run the electric fuel pump.

If anyone has a 2010 Audi A3 TDI or 2010 VW Golf TDI, please let me know which style of fuel filter you have:

 

[tokendog]

Is it possible that all those fuel pump failures mentioned are linked to the pump not running at startup? Or maybe a specific filter type? Maybe they have a loose clamp somewhere which is letting in air bubbles, causing problems in the fuel pump? A few air bubbles aren't a problem in the AHU or ALH but mine was always tight.

 

[chittychittybangbang]

I had a closer look at a 2010 Audi A3 TDI fuel filter. I'm not 100% sure of the part number but older TDI engines (not available in North America) used 3c0 127 434. I thought they used the 2 hole wide mouth filters but I will look into this further. The housing uses smaller torx bolts and one of the fuel lines points the other way. I have no idea why.