Diesel filter change - caution

   #1  

Roks200

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Greetings fellow VW/Audi lovers,

First of all, I have no intention to mock VCDS or discourage anyone from doing a filter change but i’d like to point out that the VCDS’s fuel pump priming might not work the same on every car.

Yesterday I was doing my major service on my 1.6 CAYC and found that my car wouldn’t start due to air lock. Just in case anyone is wondering, the solution was to bleed the injectors one by one using a spanner.

Perhaps someone can guide me on how to do it in the future so that bleeding wouldn’t be necessary as I believe I’ve done everything as per instructions: 01 Engine>basic settings>test electric fuel pump> 30 seconds intervals.

Thank you
 
   #2  

Uwe

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I have not done this myself, and I have certainly not done it on on a 1.6 (because they don't exist on this side of the pond), but I'm wondering...

Air at the injectors is on the high-pressure side of the system. The filter is on the low-pressure side. How is it possible that changing the filter got air into the high-pressure side? I wouldn't expect that to happen at all.

-Uwe-
 
   #3  

Jack@European_Parts

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Air at the injectors is on the high-pressure side of the system. The filter is on the low-pressure side. How is it possible that changing the filter got air into the high-pressure side? I wouldn't expect that to happen at all.

-Uwe-
It really won't and if it did it would self bleed right at recirculating weeps in first commencement of injection since CR.
 
   #4  

BOBSER1

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i have had this on my 2.7 if air gets into the line at all while changing the fuel
filter i have had to bleed the lines on each cylinder .pain in the .... . there is no prime function
on mine either .next time fill the line to the pump with diesel an fill the filter should be fine then...
 
   #6  

naushad2982

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Out of curiocity are you using Output tests or basic settings?? i usually cycle between the 2 if one doesnt work

you shouldnt need to bleed air from a system that runs from 280Bar (start of injection) to 450 Bar (idling) to 2000Bar at full throttle.

we usually crank it for about 20 seconds and they start right up!

to answer Uwes queston the common rail does not maintain Fuel pressure when the engine is switched off. the pressure regulator opens up when de-energized to release the pressure on the high pressure side.
 
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   #7  

Jonesy

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Fill the filter housing with fresh (clean) fuel when changing the filter and it will fire straight up without any bleeding 👍

I've done 100s and never had an issue.
 
   #8  

den9112

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Ive done 4 filter changes(and 4 new injectorrs ) on my CAYC 1.6tdi and always use the tail lift pump and have never had a issue.
 
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