Cold start issues on my Audi A4: Faulty spark plug replaced in warranty

The first issue was of the engine malfunction indicator light (MIL) flashing and the car slightly shaking at the same time.

BHPian amartya_bhp recently shared this with other enthusiasts.

I have been a proud owner of an Audi A4 PP+variant since Sep 2022 - a brand new car in Terra Grey Exterior and Beige interior. I have been loving this experience since I parted with my Vento TSi which served me well for about 65000 km and 6 yrs (had bought it new in 2016). Even I have got some mods done by BHPian Agam Bhandari and he helped me get rid of the speed chimes, turned on needle sweep and rear light DRLs. I have already traveled with this GEM of a machine to Kolkata, Vadodara and have already clocked about 8000 km since my purchase and loved the drives (experiences are upcoming soon in a future post, so stay tuned, please)

Off late though, my steed is in the garage with a strange fault and that is why I am putting this up here for your comments/feedback/suggestions. Hopefully, the experience in this forum will help in getting the problem resolved. So, here goes:

• The problem showed up during COLD START ONLY in the morning as of now(first observed on Nov 20). Note that I have always used XP95 fuel since Day 1.
• The first issue was of the engine malfunction indicator light (MIL) flashing and the car slightly shaking at the same time - had already visited the Service Center once on this issue the day on Nov 21, when some tests were run and faults were cleared by SA (Scanning showed random/sporadic cylinder misfire P0300 CODE - was advised that this is a random error and there should not be any issues).
• The issue was not resolved and the fault continued to show with considerable water coming out of the exhaust at the same time next morning onwards (note the AUTO START STOP function does not work even after the flashing stops and I start to drive).
• The above problems showed up every time at cold start till the Service Center picked up the car on Nov 28th afternoon.
• However, on Nov 28th, the drivetrain fault showed up on the MID and the car refused to start in the morning; after three tries, it did start but the same MIL light was flashing with water coming out of the exhaust.

As usual, service center guys at Audi Gurugram, first said that there are fuel contaminants, so they drained the fuel, cleaned the tank and changed related O-rings. But still the problem persists and the car is still with the workshop. They say that they have done engine endoscopy, compression tests and all related tests and the engine is fine. They then tested the fuel pressure and were waiting for feedback from Audi India Technical Team for the way forward.

The issue was traced to a faulty spark plug which was not doing its job properly in the cold. They have replaced the part under warranty and now everything looks good. My car is back and is running as smooth as silk.

Check out BHPian comments for more insights and information.