2.0 Tdi 8p1 Engine Judder On Idle

[A3-BEN]

HI ALL,

I NOTICED AFTER A WEEK OR SO AFTER BUYING THE CAR THAT THERE IS A JUDDER WHEN THE CAR IS IDLING. IT DOES IT ABOUT 80% OF THE TIME BUT ONLY IN NEUTRAL OR PARK NOT WHEN ITS IN DRIVE. THIS ONLY HAPPENS ON IDLE AND THE REST OF THE TIME THE CARS FINE. IT KIND OF FEELS LIKE A SHUDDER THROUGH THE WHOLE CAR. ANYBODY ELSE HAD THIS?

 

[DJ_26]

Does the car feel like it's shaking when in Neutral or Park and when you select Drive, the shake is less noticeable? Also there doesn't appear to be a fluctuation in revs whilst there is this shaking? Sounds like the dual mass flywheel is worn, it's quite a common issue. You might even here a faint pop each time you give the engine a rev.

 

[A3-BEN]

Yeah it shakes the whole car but only in park or neutral. When it's in drive it goes completely. It doesn't happen all the time though. It's intermittent and There is no fluctuation in revs but when it happens it sounds like the engines is missfireing. There is no pop at all when you rev it. I don't think it's the dual mass due to the sound that comes from the engine when it does it. It's exactly like a miss fire sound. Weird

 

[Rideen]

Check your fuel injectors. My 1st fuel injector is bad and I have exactly the same sympthoms.

 

[A3-BEN]

How do I go about checking my injectors? Is yours an intermittent fault?

 

[Rideen]

Hey, yes, it happens sometimes, not all the time. I got mine checked at dealership with Delphi diagnostics which show injector fuel rate in real time and my 1st injector gives - 3.00mg/H whereas the rest give between 0.7 and 1.2mg/H.

Edit: Can someone explain what mg/H means and what are normal values. Also, how can an injector have a negative value of mg/H?

 

[A3-BEN]

i'll give my local dealers a phone and see what they say. how much did it cost you?

 

[Rideen]

15 Euros

 

[SmithyAG]

The mg/h is fuel flow correction, so mg/H iirc is milligrams per stroke. It is the amount the injector has varied it's flow to keep it running as smooth as possible. So a negative amount just means it has allowed a little less fuel through to smooth it out, and a positive the opposite.

 

[Rideen]

Thanks a lot for the explanation Smithy!

 

[Jackx1]

Adjusting the idle revs can help, mine does it but when i turn the air con on its stops. Bizarre :/

 

[A3-BEN]

ive tried putting my foot on the accelerator to increase the revs slightly and its still the same. i wonder how much it will cost my at my local dealers in england

 

[Rideen]

ive tried putting my foot on the accelerator to increase the revs slightly and its still the same. i wonder how much it will cost my at my local dealers in england

Same here mate. It disappears only after ~1200rpm.

Fuel injectors fixing costs 600 Euros for all 4 injectors here.

 

[A3-BEN]

Does the car feel like it's shaking when in Neutral or Park and when you select Drive, the shake is less noticeable? Also there doesn't appear to be a fluctuation in revs whilst there is this shaking? Sounds like the dual mass flywheel is worn, it's quite a common issue. You might even here a faint pop each time you give the engine a rev.

Just phoned the company that I got the car from as I've only had it 3 weeks and have 3 months warranty and they said it is most likely the DMF. Taking it to them tomorrow for them to check it out. Does anyone have any idea how much it would be for a garage to change the DMF roughly? I'm covered for upto £1000 so hopefully it will fall below that