Ive had my octavia 110 tdi since nov 08 and no probs till now the engine has started to miss fire in low revs and ive noticed as it miss fires the exhaust throws out alot of black smoke. Im really stuck as theres no engine management light coming on and now the the car is staring to make some strange noises. Can anyone help please???:confused::confused:

The black smoke is simply un-burnt fuel, there could be several reason for it being un-burnt, timing out, bent valve etc

As Gizmo says, black smoke means the engine is over-fuelling. There are any number of possible reasons for this.

Your best first bet would be to try disconnecting the MAF sensor (wiring plug on aircleaner to trubo pipe) and see if that sorts it. If so, replace the MAF.

After that, try removing the air cleaner element, and then if that doesn't help go on to VCDS.

thanks i will give that a go. and keep you posted

:Ohi all just disconnected the air flow meter the black smoke has gone (woo hoo) but now the car has lack of power on the top end!!! Any suggestions anyone would be greatfully recieved

The disconnection of the MAF has proved that the MAF is faulty, you now need to get a new one to replace it and reconnect the wire, then all should be back to normal.

Source a new MAF, and that should give you the top end back. The reason the trick works as a test is that the disconnection forces the EMS onto a default fuel/air ratio, instead of feeding the injectors rubbish data on fuel requirements.

just put a new MAF on the car a very big thnxs to all that helped me the car is running a sweet as now what a head ache it was trying to figure it out. thnxs again trish x

Edited 2 October, 200916 yr by triton0143