04 1.8T engine management light on! Advice please

[Ratha]

My girlfirend has a 1.8T 04 plate A4 cab. she started it the other day and the engine management light came on and it started to run lumpy, as in sounding like it was a cylinder down. I have checked the core/coil plugs and found that the number 1 cylinder wasnt working. i have replaced with a genuine VAG part and it has sorted the issue, as in all of the cylinders appear now to be working and when you remove all of the the core plugs you can see it sparking and hear them clicking etc. however it is still running very lumpy when idling. It appears to cure when you give it some revs partly. Any ideas?
​

 

[AU01 A4]

Crank Brather vale there a lot of threads on here about it

 

[AU01 A4]

here you go just get it scaned fist and post up the results
http://www.audi-sport.net/vb/a4-a4-...nning-lean-bad-idle-problems-after-remap.html

 

[Ratha]

cheers, gives me a place to start looking. I'll get it scanned.

 

[pj123]

Poor idle can be from any of the following:

MAF, Ignition Coil, Spark Plug, VAC Leak, O2 Sensor, Throttle Body or Temp sender.

Cleaning the TB is a cheap an easy place to start.
Unplugging the MAF tests if the MAF is faulty
Temp sender / o2 sensor you'll need to do a scan.
Vac leak, look for split hoses or data logging using vag com

Not sure if the 3 older coil packs are weaker in any way and could make a difference?

 

[CHRIS555]

Crankcase breather valve for sure - let ne kniw if you need the part numbers etc, its a £6 part and a DIY job

 

[itsmeagain]

I had the same problem on my cab, I replaced the valve and it cured the problem. Easy job to do