Fuel filter questions

Bosun

Member
Joined
Aug 7, 2013
Location
Saint John, NB, Canada
TDI
Golf Sportwagen
It’s time to fuel filter change on 2015 CRUA TDi, is anybody experience do that?

1 Q: Do I need purge air from fuel system? If so, what is you use, VCDS? On PD MK4, I didn’t, and fuel pump primed by self after start, but I don’t know on CRUA.

2Q: Did somebody used Liqui Moly Diesel Purge on this MK7 CRUA? I used it periodically on PD with good result. Can I use Diesel Purge during fuel filter change, just fill fuel filter with it and start engine, run on idle till it will gone, usually 5-10 minute?
 

hskrdu

Top Post Dawg
Joined
Oct 17, 2003
Location
Maryland and New England
TDI
2003 Golf GLS 4D 5M, 2015 GSW SE 6M
I've changed the filter as part of routine scheduled maint. Remove tiny torx screws, remove the top cover, old filter out, new filter in, add fuel or additive to the new filter until full, replace top cover. Some notes: It may be helpful to have some replacement torx screws on hand (IDParts sells them); The top cover is in close proximity to the rubber on the top of the fuel filter, so removing the cover quickly will splash diesel around- it's best to remove carefully and have some rags ready; I drain fuel from the old filter into the new filter, and then top off with LM DP; As always, have a receptacle ready for the old filter (or 4 hands); Have a narrow funnel on hand for filling the new filter. I did not do any air purge or VCDS operation for the filter change, and mine started easier than some ALH changes I've done. I do not sit and idle after the FF change, just start up, visually inspect, and move on. The few ounces of DP in the filter will soon be mixed with the rest of the fuel. HTH.
 

JM Popaleetus

Veteran Member
Joined
Mar 15, 2010
Location
Connecticut
TDI
Signature.
You can use VCDS to prime the pump. I do because I have it readily available and don’t bother buying Diesel Purge.

But the easy method: Remove old filter, insert new filter, fill with fuel or Diesel Purge, and tighten all five screws to 5nm. Done.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
diesel purge will be dispersed through the tank way faster than doing any benefit to the injectors.

remember Diesel Purge is a product of a different era, not really needed on modern injectors with ULSD.

I usually top up with Power Service and call it good, too lazy to prime and this counts as my once every 20K fuel treatment/injector cleaning.
 

brew1

Veteran Member
Joined
Dec 18, 2004
Location
Richfield WI
TDI
15 GSW SEL TDI
This weekend i'm ditching the OEM filter setup and converting to the Nicktane setup using Baldwin BF7633 2 micron filter.

The Baldwins are cheap enough to replace at the same time as the 10,000 oil/filter change.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
whooa wait? you're doing 10K oil changes?

that's sadistic, do you not love your TDI? Get with the program change the oil every 3k, change the fuel filter while your at it too.

As you said, filters are cheap.
 

brew1

Veteran Member
Joined
Dec 18, 2004
Location
Richfield WI
TDI
15 GSW SEL TDI
Yep, every 10,000 miles or once a year whether it needs it or not.

Gotta luv folks that support oil companies with 3,000 mile oil changes.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Or people supporting fuel filter companies and 10K filter changes ;)

Say you get 40MPG that a fuel filter ever 250 gallons of fuel, say you fill up every 12 gallons, that's one fuel filter per 20 fill ups. Almost sounds as crazy as 3K oil changes.

Buy your right filters are cheap.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
i think injectors are the least of your worries ;)

Maybe i'm just lucky to have access to quality fuel. QC of ULSD seems to have dramatically improved since 2006.
 

brew1

Veteran Member
Joined
Dec 18, 2004
Location
Richfield WI
TDI
15 GSW SEL TDI
ROTFLMFAO
Another good one 740 GLE.
Your constructive criticism is much appreciated.
You are just a wealth of valuable information.
 
Last edited:

Smithmsdjsx

New member
Joined
Apr 29, 2021
Location
Tacoma, WA
TDI
2012 Jetta TDI, 2015 Jetta SE TDI
You can prime with OBDeleven also.
Have you performed the steps for activating the fuel pump? Where is that function? Been looking for it on the OBDeleven? Any suggestions would be greatly appreciated, thanks!
 

brew1

Veteran Member
Joined
Dec 18, 2004
Location
Richfield WI
TDI
15 GSW SEL TDI
I used the Ross Tech program on my pc via the OBD port. Filled the filter with Power Service then cycled the pump a few times with the program and then started it right up.
 
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