04 1.8T engine management light on! Advice please


Registered User
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?
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Had an 8L S3, a B5 RS4 now I have a B8 S4
Hi man - welcome along!

Do you access to VAGcom or a scanner to check what fault codes are showing up? that's the easiest way to tell.

Apart from that Is it getting up to 90 and staying there?

If so does the lumpy idle fade when the car has warmed up?

Has the Mass Air Flow sensor been recently changed?

you could have a boost leak... the list goes on and on lol.

Get in scanned and you should know alot more.


Registered User
Cheers for the quick reply. I will get it scanned then as a start, as you say it should give me a steer in the right direction. Not to sure on the other answers as its my GF's car. thanks for the help, appreciated.