A6 2.7 tdi quattro fuel pressure issue

[scruff]

Hello

Hoping to get some help on an issue I have with my a6.

A few weeks ago while driving the glow plug light began to flash constantly and the car went into limp mode. I pulled over turned the key off and on and away I went.

I called in to see my mechanic who plugged in his computer and it showed a low fuel pressure fault and a ash content full on the dpf. He cleared the faults and I tried the car again and it went back into limp mode and noticed the fuel line coming from the fuel filter was making a buzzing noise and when the engine was off an air bubble appeared in the clear fuel pipe just before the hpfp.

He plugged the computer back In and it only showed low fuel pressure fault, He suggested I change the fuel filter to see if that would cure the issue.

I replaced the filter but still the car goes into limp mode with the glow plug light flashing. I've since sent the injectors off to be tested 3 came back with an issue of not giving a calibration code??? My mechanic doesnt know what that means or do I.

When I spoke to the guy who tested the injectors he said refit the original injectors and replace the fuel reg which is on the back of the fuel rail to see if the issue has gone.

I've since put everything back on the car tried it and still the fault is there but also the dpf light is coming up on the dashboard.

Would a dpf fault cause the car to have a low fuel pressure fault? 

Sorry for the long post but really struggling to get the car fixed and don't have a fortune to spend on it

Cheers 

Gareth

 

[Rossi01]

Hi Gareth, I am in the same position. Did you ever get to the bottom of this.

 

Regards

 

[scruff]

On 5/31/2024 at 8:42 AM, Rossi01 said:

Hi Gareth, I am in the same position. Did you ever get to the bottom of this.

 

Regards

 

Yes, the low pressure pump in tank has a very fine mesh filter which was blocked just enough to put it into limp mode. Do not attempt to pull the pump apart like I did as it broke the plastic cup that the pump sits in and I had to buy a new one at a cost of £508!!!!! Main dealer part only.

Drain the fuel tank and give it a good clean if it is the same issue I had