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View Full Version : Shudder while driving (again), no fault codes & VCDS question



Lizard_Of_Bodom
01-04-2024, 03:54 AM
Hi all
For the second time since I got the car I experienced the power loss yesterday when driving. First time happened like month ago, ignored it "to observe" but yesterday it happened again, this time when cruising 110kmh on 4th gear @3000RPM (DSG in Manual mode). Car just lost power & reaction to gas pedal for about second, maybe 2. It felt like fuel supply was cut off or something similar (just describing the feeling). No engine light, no errors on dash, also no codes stored after checking with VCDS.

130k kms on the clock, 2012 S4 B8.5, fully serviced since I got it at 120k kms (all fluids, spark plugs etc). Have the car since August.

- If that happens again (and I have feeling it will) - what can I do to pinpoint the issue further? Is there any way to retrieve any useful data if no fault was stored? I understand VCDS would retrieve freeze frame fault info if there was fault stored but otherwise is there any data I can look for anyway?
Not gonna drive with VCDS conencted & logging (for now) as it happened only twice within last 10k kms, so far.

- any pointers what I can observe visually when that happens again? I already excluded DSG issue (first time happened on acceleration, thought it could be gear change hesitation), yesterday it was on steady cruise. Fuel was way above reserve, coolant temp in the middle, car was warmed up atleast 30mins.

- do you recommend using injector cleaning fuel additive to clean up the system a bit in case its related to fuel? Using 95 (E10) in Ireland.

many thanks for any tips.

MrFunk
01-04-2024, 10:57 AM
Sounds like almost a traction control fault.

Lizard_Of_Bodom
01-05-2024, 02:46 AM
Sounds like almost a traction control fault.

Didnt even think of it, thanks for input. Although I would expect TC icon to flash on the dash?
Regardless, if/when it happens again ill try to check if switching it off makes any difference, thx

MrFunk
01-05-2024, 01:16 PM
It very well could be something else, but the symptoms remind me of when traction control cuts power...
Fuel pump? Injectors?
Have you asked the Dealership to check codes?

Lizard_Of_Bodom
01-07-2024, 11:00 AM
It very well could be something else, but the symptoms remind me of when traction control cuts power...
Fuel pump? Injectors?
Have you asked the Dealership to check codes?

As I mentioned, there was no codes stored at all, I checked with VCDS.
Yesterday though the codes DID appear but after misfire and cylinder deactivation (created separate thread (https://www.audizine.com/forum/showthread.php/985955-Cylinder-misfire-EPC-light-ok-after-restart-Error-codes-included)about it ) and Im not sure is it related or just stupid coincidence as it just behaved compeletely different to original fault I was reporting.