3.0 TDI - Fuel filter check

['WG']

Apparently the fuel filter can be checked visually for possible signs of contamination. Im my case this is for oil, since i have a suspected faulty injector. Is this simply a case of removing the split pin on the circular return line fitting at the top of the filter, and pulling it off to have a look? If so will this trigger any EML/MIL lights, or codes, or air locks? Will it reseal ok afterwards? WG.

[gupsterg]

Chris's guide on fuel filter change, Link- VW Audi Forum - The #1 VW Group Community

Yes you can reuse valve.

If you do drain FF into a container I'd refill it on refitting, this will make starting easier and reduce impact of air in fuel system.

IIRC I didn't get a EML/MIL as refilled FF, if you do happen to get one after x starts/detection fault is not re-occurring it should go away IIRC.

You should be able to see a date stamp on FF, I'd probably replace it if doing what your doing unless already newish/no contamination in contents.

I got genuine VAG ones off ebay cheaply for last 2 changes.

['WG']

It was Chris's guide that gave me the idea, that perhaps since the only way oil is likely to enter the FF is via the return line and the fact that oil will float due to its lower specific gravity, any oil might easily show in the hole just under the return valve. That would save all the trouble of removal, testing in a glass etc. Not as thorough, but easy peasy.

I'll have a look on eBay, thanks for the info.

[gupsterg]

Indeed you may well see it through the return valve hole , so that's way I said "If you do drain FF..." .

['WG']

I might give that a go then - thanks Gup' .

[gupsterg]

No worries .

The injection system is self bleeding of air from what I read in the official VAG service guide.

Like I said in the PM if you don't have VCDS to switch fuel relay on cycling the ignition up to cranking and then back, then removing key and reinserting should make the relay kick in again.