2011 Octavia vRS morning rough cold idle

[Anowak]

Hi people, bought this car in Feb.

Done over 11k miles so far and as the cold is coming in I've noticed it struggles to "Find" idle and stay there for the first 30s-50s after morning start up. Seems to run on 3 cylinders when this occurs, I'm thinking coils personally. The car shoots up drops to 1100rpm then starts to drop lower and lower violently till it struggles to idle but doesn't stall. I can rev it a bit to keep it from doing this if I stay above 1000rpm for the first 20s.

2.0 TSI

Recent Spark plugs

Pulls amazing once warmed up and idle is steady at 770rpm

Starts & idles fine in temps above 3C - 4C

 

No Lights on dash and no codes  when this occurs. (Need to check for them again)

Doesn't burn oil

Averages 32-35 mpg

140k Miles

Allegedly had a new engine + turbo at 116k

[brown_d9]

Possible inlet valves / throttle body all gummed up with carbon?

 

 

[TheClient]

Almost certain intake port and valve carbon build up. 

[brown_d9]

This is what mine looked like before and after. Around 90k miles of gunk.

[Anowak]

9 minutes ago, brown_d9 said:

This is what mine looked like before and after. Around 90k miles of gunk.

How easy is the intake manifold to take off? and what did you use to clean these?

[brown_d9]

Its a fiddly job to replace the manifold, particularly the lower bracket bolt but all do-able on the driveway. (need special tool and seals just in case any fuel injectors come out during)

 

Dental picks and Mannol intake valve cleaner... its hard work but doable. I wouldn't do it this way again, I would go the walnut blasting route.