4,2 TDI - juddering/hesitation at 1200-1600rpm

[centurion]

hi guys,

and i'm new to this Audi [having spent some time on other Audi related ones in the past].

i recently bought an A8 L and it's been a magnificent car for months only to notice slight judder/shudder [e.g. hesitance] recently. it is mainly manifested when eng temp is still relatively low in 2nd and 3rd gear when moving slowly through gears @ 12-1600 rpm. If one was to push the accelerator pedal hardly you won't notice anything.

i read several articles about g'box oil change but before i go down that route could anyone shed any lights what could be an issue... car has 140k miles on the clock and it has been maintained regardless of cost by the Audi main dealer.

i also have access to VCDS and have attached extract re only transmission related error...


Address 01: Engine Labels: Redir Fail!
Part No SW: 4E1 910 409 A HW: 4E1 907 409
Component: 4.2L V8TDI A000AGMª0070
Revision: --H01--- Serial number: AUX3Z0F0383728
Coding: 0011773
Shop #: WSC 00097 210 80549
VCID: 224B0C03FD3A2A0EA27-8077


1 Fault Found:
006217 - Please check DTC Memory of Transmission Controller
P1849 - 008 - - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 227660 km
Time Indication: 0
Date: 2015.02.05
Time: 00:00:07


Freeze Frame:
RPM: 0 /min
Torque: 3.9 Nm
Speed: 0.0 km/h
(no units): 0.0
Voltage: 6.54 V
Torque: 795.6 Nm
Bin. Bits: 11000000


Readiness: 0 0 0 0 0


-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 09E-927-156.lbl
Part No SW: 4E1 910 156 P HW: 09E 927 156 B
Component: AG6 09E 4,2lTDI RdW 0030
Revision: --H01--- Serial number: 0076614
Coding: 0000001
Shop #: WSC 02313 785 00200
VCID: 306FF64BA3D6889E243-8065


No fault code found.

[Architex_mA8tey]

Welcome to the forum

Looks like a stored fault from the transmission ECU from over 2 months ago - clear the fault and see if it returns. I would certainly check the gearbox oil level to see if you've lost any fluid, and then finally possibly change the oil and perform a gearbox adaptation to go with the change, which your dealer would need to do

[centurion]

will certainly give it a go tomorrow... any other hints as to what to look for in VCDS?

i also checked under the car while at the garage to replace worn tie rod ends and it has no sign of oil leaks or similar.

As for oil change any 'reputable' garage around London area that could do the oil change + adaptation?

Much appreciated.

[centurion]

quick update...

successfully cleared all faults however that hesitation/juddering is still present.

I will try and eliminate the combination of MAF + EGR over next couple of days by disconnecting the earlier and [manually] cleaning the latter [will be a weekend job i'm afraid]. i also planning to do the gearbox oil change regardless so all in all i hope that one of or combination of all listed options will provide the cure .

One other options in the 'quick win' book though... i ordered Archoil AR6400-D Pro PEA Concentrate Diesel Cleaner that does apparently help with removal of gunk/carbon in EGR and vacuum pipes/lines so hope that should give em at least an indication if MAF/EGR is indeed the culprit in this case or perhaps something else.

Fishing continues ...