Big turbo TT

Probably injectors! They tend to act up when cold/idle more so than under load. I have replaced FSI injectors that idled badly but "drove" just fine. Yeah for modern technology!!!!
TFSI

Totally
Fecken
Sh**ty
Injection system!!
Just like DSG
Das
Sh**ty
Gearbox!!

JD15

I had TSB 2024812/4 performed today, which includes the following:

Software Update
Replace Pressure Regulating Valve
Replace Front Crank Seal

The dealer believes that this will fix the rough start issue and excessive oil consumption. At least the dealer performed the TSB without a fight and did not give me a "could not replicate" or "all A4s are like that" type of excuse.

CoffeeMonster

I've had this same thing happen three times in the past couple weeks. I have a little over 17,000 miles. No solution yet - will take it in next week. I thought I'd search here for "EPC" first. Good luck!

JD15

The TSB seems to have fixed both the rough start issue and the excessive oil consumption. The car has not started roughly since I had the TSB performed over a month ago and oil consumption has decreased from 3/4 quart in 800 miles to still reading full on the MMI after 450 miles. Hopefully, your dealership is receptive to performing the TSB.

JD15

Time to revive an old thread. While driving this afternoon, I accelerated from around 30mph and my car started shaking violently, the check engine light started flashing, and almost all power was lost. I immediately pulled into a parking lot and restarted the car, but the result was no better: The car shook violently even when idle and could not driven safely at any speed. The car is now sitting at the repair shop and will hopefully be diagnosed tomorrow morning. Based on my research, it appears that the following could be the culprit, in order of likelihood: fuel injector(s); fuel pump; POS plastic intake manifold.

Anyone have a similar experience?

pierreb

coil pack would be easily first guess.

JD15

Yes, it was a coil pack. I knew they were problematic in the B6 and B7 generations, but didn't expect to see them failing at 33k miles with the B8.

pierreb

yeah they fail often on both of my B8s. I believe tuned cars are even more prone to it.

Eduard I

I have had this issue happen to me while driving on the highway today. My car started shaking and losing power, EPC light came on then the Check Engine Light followed. Thankfully, the highway was busy and I was able to safely pull over without causing any traffic.

I was able to load some codes and they were relating to multiple cylinder misfires (1 , 3 , 4 , and 6 I think). I am out of warranty and was wondering if this is a problem that persists with the B8 S4? Worth it to sell? (Currently have 130000KM on my 2010 S4)

JD15

Check and see whether it is the coil packs. If it is, it is a fairly simple and inexpensive fix. It is bothersome that Audi does not include coil packs on the maintenance schedule.