A4 TDI 110 IDLE ISSUE(Yes guys,another thread looking for help lol)

[Keithsri]

Hi,so thanks for all previous help giving when i ask questions...much appreciated,but heres whats bugging me now


Sometimes(very commen)if i let the car idle,it seems to run rough,and shakes the car,if i give it a rev ,it go's away..and idles normaly,and may or may not come back,i watched the rev hand,it doesnt seem to drop at all, itl just be sitting there,idleling fine,then it will instantly just run rough and shake and its louder than idle,it makes the whole car shake.... Its getting verrrrryyy annoying


Now,i have changed,air filter,fuel filter,took egr and inlet off and cleaned out loads of gunk from there, unplugged the maf,the car didnt drive well,plugged in again,it drove fine,checked for vacuum leaks... theres only 98 thou miles on it

What else is there????? as no1 near me has vagcom,im thinking about buying a cheap ebay lead and having a look myself? anyone recommend one?


Thanks for any help

 

[adamss24]

Seems to me that the duall mass flywheel its worn out. Does it do-it only when the engine is hot or is it doing it from cold also ? If its doing it from cold, then it could be a faulty injector or plugged EGR valve... I would check for fault codes first if none found then it's the flywheel.

 

[aragorn]

I have to say that seems a very big jump to me?

The flywheel on our 1.8T was completely knackered (after 195k), and at one point jammed making pulling away a horrible juddery experience, but it never made the car vibrate, other than when slipping the clutch. Similarly the flywheel on my mates volvo went it was juddery when slipping the clutch but fine when engaged.

 

[Keithsri]

Thanks for the replys..


More so when its warm,doesnt happen when cold useualy.... also When i let my clutch out i can feel it judder slightly,but doesnt make the car jump or shake at all,i assumed this was a flywheel,but i know plently of vags with the same issue,and no idle issues or flywheel issues for a long time yet,as its slight judder just..


I was thinking faulty injecter aswell,theres no way to check these is there?or can you by computer?? as said may go to a friends garage who uses snap on machine to see if they find any fault codes,but still gonna buy an ebay vagcom lead for fun lol!!


Thanks

 

[adamss24]

If the car iddles ok when cold and starts to vibrate when the engine is warm AND there are no fault codes, then the DMF is toast. The DMF have 2 axis on wich they can play. first from side to side (wich is it in your case)n and the other up/down wich will judder. Its because the flywheel has been abused at some point( towing, riding the clutch, drag starts) and the grease imersed springs inside the DMF boil thus loosening their elastic properties. When cold the engine turns slightly faster and the grease is denser hence the better feel. As soon as the revs drop(when engine warm) the innards inside the flywheel re-arange themselves thus causing the vibrations. On early tdi with DMF, the clutch disc also have dampening springs hence beeing less juddery on take-off, later PD tdi's have a solid disc plater and rely on DMF for dampening the vibration-hence the more common failures(in-built un-reliability) - and they are also much more torquey as well wich will wear the clutch in weird ways... I would take the car to a diesel specialist/good mechanic and if there are no fault codes, then i know where i would look. You can check smooth running iddle of the injectors with vag-com if they are within spec and under 200k i would leave them alone.

 

[manzi]

i think i have this problem

i have a facelift model but a none PD engine i think. done 187k now.

this a lengthy job? coz i'm gunna need to scrape the pennies together if so

 

[Keithsri]

That does sound like it adam,.. but why when i give it a wee rev would it go away and might not start til another 5/10 mins???? hmmm I think the answer lies withing vagcom anyway!! Need to start there.

Thanks

 

[AUDI-FAQ.COM]

Use vagcom to detect the errors. Without it all works are usual guessing.