16785 - EGR System: Insufficient Flow

[chrisgeary]

Hello,

I have a 3.0 Tdi reporting:

16785 - EGR System: Insufficient Flow
P0401 - 002 - Lower Limit Exceeded
Freeze Frame:
RPM: 2037 /min
Torque: 187.2 Nm
Speed: 114.2 km/h
Duty Cycle: 51.8 %
Duty Cycle: 20.9 %
Mass Air / Rev.: 581.6 mg/str
Duty Cycle: 58.4 %
Mass Air / Rev.: 405.4 mg/str

I cleared this yesterday and it came back today. Not sure if the car is down on power or not, it feels pretty ok to me.

What might be the cause?

[Dpanic]

Might be the valve, but check the hoses to and from the valve - for any sign of splits.

Have you lost power?

Regards rob

[chrisgeary]

I don't think it is down on power. Feels good, nominal levels of soot from the rear under full throttle, I'll check the hoses, no other engine fault codes that I might expect with a split hose. I guess if it isn't bring up an alarm on the dash and there isn't a power loss, perhaps I should just ignore it?

[GRBspeedster]

Might be worth taking valve off and cleaning out. it is an easy job. My daughters was vitually blocked when i checked it

[chrisgeary]

Thanks... I'll investigate.. just need to find a handy how-to now

[GRBspeedster]

At local GSG noted they sell spray EGR cleaner , worth a try

[coolraj003]

I had to clean mine on my last car a few times and i used the brake cleaner spray, its mostly carbon/soot build up that causes the valve to jam. Once cleaned and plugged back in its good to go until it gets jammed again. hope you get it sorted out but there isnt a sure shot way to resolve this issue as it will come back again as the carbon builds up in the valve. Luckily it doesnt have any negative impact on the performance of the car other even when it did bring up the Engine Management Light on the dash but that was my experience on the other car. Shouldnt be too different from this one.

Raj

[a8 tech]

check the intake flap as this sticks

your info shows egr is on and should be off at this rpm, as the airmass is high but I would check the intake throttle housing and make sure via output test it shuts off fully and opens fully first then output test the egr and check it opens in accordance with the duty cycle %

Remove the intake throttle housing and check the egr ports inside, if blocked clean them then check the egr is not sticking open as your values suggest clogging/egr leaks

the tell tale is the airmass isnt liking the values

Duty Cycle: 51.8 %
Duty Cycle: 20.9 %
Mass Air / Rev.: 581.6 mg/str
Duty Cycle: 58.4 %
Mass Air / Rev.: 405.4 mg/str