Vibration/wobble on tickover

[A4 nut]

Hi my father in laws 2003 a4 avant 1.9 tdi has devloped a kind of wobble on tickover its not miss firing could it be an engine mount or gearbox mount gone any ideas?

 

[simon.m]

i had this on mine some one on here said to clean the injector harnes witch i did and has been good so far but i think ill need a new one soon any way could be that mate with mine it was a lumpy kind of thing very strange the hole car was well just lumpy like the engine was bobing up and down

 

[Rigla]

Mine is doing this aswell, it only does it when its warm and its worse if the car is on a incline and decline. I'm geting it diagnosed on Thursday but i'm 80% sure its the Injector wiring loom

 

[simon.m]

i get it some times after a good run

 

[scottie 81]

I get that too

 

[Phil.MC]

I thought it was just a characteristic of the 1.9 PD 130 engine? I've had this on my last two Seat Ibiza PD130 cars.

 

[simon.m]

oh right well im sure it should not be there as its rather annoying and dose not do it all the time but would make seens as it dose not show up on a scan

 

[ian-r]

Hi all,

Mine does this as well. whole front of the car jumps about when warm. Been looking and had it on vag com and suspect i need to the the hammer mode the reset the injector quantity as mine is out of parameters. Looks easy to do, have adjusted but cant get it close enough. See this link - TDIClub Forums - View Single Post - injection pump repair, fuel quantity

Ian

 

[simon.m]

that is way over my head ;-) and have to say i dont no how it would adjust its self to be out if they have not been changed buy some one but like i say thats way over my head so i may be wrong

 

[deanski]

mine also does this. local garage reckoned its the hydraulic engine mount but i'll look into the injector thing. anyone got a link as to how to clean it and are they expensive to replace?

thanks

 

[simon.m]

the harnes you just take the rocker cover off and you can see the wiers give them a clean and pop them back on i did it to mine help but think if it starts up again ill just buy a new one im told under £50 pounds

 

[Garfie]

Mine occasionally suffered from this too. I just adjusted the tickover speed slightly with vag-com to a speed where it idles smoothly.

 

[simon.m]

good idea as if i blip the revs a weeeeee bit it gose

 

[ScottyP45]

mine is exactly the same, and a blip to 1k rpms smooths it out, but mines a Bosch VP37 distro pump unit, TDi 110.....it is in my case, I think, a small fuel leak from one of my injector pipes. Holding 1k instead of 850 idle makes the fuel pressure rise, and picks up the dragging cylinder thats getting the low pressure. Idle fuel is the equivalent of a tiny drip of diesel, around 1cc or less, so if a drip falls, thats the drip that would have got pushed thru the injector on that line.

On a common rail unit it could be a faulty injector that isnt opening with the tiny idle pulse it receives, or the rail pressure may be near the low limit. Check the difference in fuel pressure on vag com between idle and 1k rpm and see if its within spec. Should be close but if way differnt then either the pump is worn or the fuel pressure sensor may be duff.

And check for fuel leaks, even tiny ones. Also your IAT may be giving the wrong idle air temps to the ecu, but you would be able to pull a fault code for this if its open circuit or shorted, wrong values however will cause wrong fuelling, and may contribute with no code to see.