Have you had faults with the V6 TDi fuel return system?

[gupsterg]

Hi ,

Any of you V6 2.7/3.0 TDi owners had faults with fuel return system? besides leaking fuel from the fuel pipes...



So red box is the pressure retention valve on the fuel return... red lines is the pipework...

Why I ask is Link:- A6 2005 3.0 tdi fuel return lines

TIA
G

[gupsterg]

So has no one had any issues/replaced ?

The tool required to test the pressure in the return system is a VAS6330 Link:- http://vw.snapon.com/SpecialToolsDet...=Fuel%20Supply

[gupsterg]

Whilst googling around found a great thread... only problem its in Russian ...

Link:- A6 C6 3.0TDI float turnover Link:- Translated

I'm finding Google Chrome with auto translation is best for viewing thread...

The thread seems live... on page 1 you will see a log of some errors concerning common rail sensors I don't have those...
I've registered to see if can get an answer, my Russian is not great ...

These are the sensors/actuating valves on the common rail...

N290 Fuel metering valve (Link:- the Q7 engine code BUG) located on high pressure fuel pump, been tested by VCDS module 1 "output test"...

N276 Fuel pressure regulating valve (Link:- the A4 engine code CAPA) located on the end of fuel rail bank 1, been tested by VCDS module 1 "output test"...

G247 Fuel pressure sender (Link:- the A4 engine code CAPA) located on side of fuel rail bank 2, been checked via VCDS module 1 MVB 22 & 23...

On this diagram you will be able to see some of the elements as well Link:- Fuel rail injection unit pressure pipes 2,7/3,0ltr. 3,0l. Fits: Audi | Jim Ellis Audi Parts

N276 = item 4 , G247 = item 3 , Fuel return system = item 36

The pressure retention valve has no wiring thus my assumption is that VCDS will not show a fault/wear with it in log/MVB...
If anyone has any info please post... after reading about wear in above thread and info in guide I think it could help my "idle issue" but not sure ...

The return system is around £175 which includes the pressure retention valve and all hoses... when I equate cost for diagnosis/travelling/time and knowing I have some surface cracks on piping I'm inclined to change "system" but hesitant to plough another £175 into car...

Related info also google for SSP 351 The common rail fuel injection system fitted in the 3.0l V6 TDI engine (pages 6 & 7)...

[motionpotion]

@gupsterg not sure it's the same thing you are referring to above but I've had some leakage from the fuel filter where on the top of the fuel filter a pool of fuel would accumulate. I'd then wipe it off and it would start over again. Eventually dirt and dust accumulated in the fuel on top of the fuel filter and mostly soaked the leaking fuel up. It's now not leaking at all but I haven't done anything to fix. It seemed to be coming out of the pipes connecting the top of the fuel filter.

[gupsterg]

Thanks for the response mate ...

My fuel filter has no leaks or fuel residue, I will add photo later to this post... Link:- Fuel filter 2,7/3,0ltr.. Fits: 2010 Audi A6 | Jim Ellis Audi Parts

My return system (bank 1 photo above) has no fuel leaks or signs of leaks...

Even if some on big bends bank 1 & 2 have surface cracks...



My query is the valve you can see in post 1 image... if that does not retain 10 bar pressure in fuel return system injectors do not operate correctly...

i) I either have test carried out using pressure gauge as VCDS can not check that valve, one place I rang did not have tools, last place will be Audi dealer...

ii) Replace complete return system, why I can't commit to buying yet is the idle fault happens intermittently so if pressure retention valve faulty would it not be happening all the time? but looking at how it work (ref SSP 351) varying return pressures could cause fault ...

[gupsterg]

I was so today when my inbox came with an email of an offer of a fuel return system for 1/4 of the main dealer price...

Only problem is that the revision of part meant it is a 6 bar valve ...

So far my investigations mean 059 130 218 D or F or H or Q or AF are appropriate as they are 10 bar valve...

The Russians also had a Bosch equivalent part no 0 928 402 061 ... available on Link:- Amazon.co.uk - Bosch 0928402061

I've also looked into tools to do pressure check at home... I can practically guess when it will do it at startup now...

Why I'm not thinking of taking it to someone is that a long drive can mean engine/parts are warmed up that then even after period of cooling it will not do issue...

It would be great if someone on the Russian forum who has replaced valve could give some more answers to my last post... even better would be to get someone from here to give some insight...

So as I'm hesitant to blow more £££ on the car I'm going to play the waiting game for cheap part/tools or info...

[gupsterg]

Right have found a Bosch P/N which is coming in at £75 , how?

First search in Bosch online parts catalogue, selected "Product search" then "External number" ...

My pressure retention valve has P/N 059130218D on it, I did a wildcard search ie 059130218?

Bosch Fuel return sysytem.jpg

VAG P/N 059 130 218 D superseded to F then to H
VAG P/N 059 130 218 J superseded to Q

Some googling then revealed 0 928 402 066 is appropriate now to contact seller for more info ...

[florin_bv]

Hi Gupster, I know that this is an old thread but I vas thinking you might be able to give me a bit of help. Do you know what the yellow circled part does, can it influence the starting process and what would be a part number for it as t was losing fuel a few months ago. I did manage to get it tight but still thinking it might be broken. Also how can you test the pressure retention valve ?

[gupsterg]

The item you have circled is a simple banjo bolt, it allows connection of the fuel return from fuel pump and injectors to the fuel filter.

In below image green line is return pipe from fuel pump, red line is return from injectors, purple line is return pipe to fuel filter.

Attachment 24973

The P/N for the banjo bolt is N 021 071 7 but I think your bolt will be fine and you need to replace the O ring on it, P/N: N 013 813 3

Method for testing the pressure retention valve is using a pressure gauge, VAG tool is in post 2. Here are images of it Link:- VAS6330 , I can not post the images showing it fitted but in that search 7th image.

You remove a fuel return pipe off injector then fit hose 1 in below photo to injector, hose 2 to fuel return pipe that you removed from injector, then start engine and view gauge, approx. 10 bar is what should be held is pressure.

Attachment 24975

Just as a side update to other members I recently found brand new Bosch P/N: 0 928 402 961 VAG P/N: 059 130 218 H for £65 Link:- BOSCH Hose, fuel overflow Common Rail (CR) (0 928 402 061) buy cheap online - AUDI, Volkswagen

[florin_bv]

Yesterday I've done an output test and all the values are similar or the same with the one from your video gupsterg ( Audi A6 V6 VCDS Engine output tests - YouTube ) except on Fuel pressure regulator Valve N276 even if the duty cycle is fine the pressure shows 0.0 bar and the same on Valve for fuel metering N290 Duty cycle fine but pressure 0.0 bar . On full scan I don't get any error . Any ideas please as I think this is the issue with my random weird start (like dead battery for a second or so) at hot