burns 1 Posted February 23, 2014 Report Share Posted February 23, 2014 (edited) Afternoon all. Sorry for long post, but I'm hoping someone can help.Running a 56-plate Mk2 TT V6 S Tronic. Recently serviced (mid January) and had new spark plugs.In the last couple of weeks it's started intermittently running like crap. This can start from cold or can be when it's getting up to temperature, or when it's warm. Literally any time. It misfires, runs rich, runs lean, snatches gears, feels like it's about to stall when slowing to a stop, occasional dark emissions, and smells like an old car.Had it scanned three times.First time: two faults on post-cat lambda, one saying running lean and one saying running rich.Took to garage, had second scan: both of the above plus misfires on cylinders 1 and 3. Tech says not coilpacks and says let's see what else it chucks up, so reset codes. Runs fine for 24 hours, then it starts again.Third scan: misfires on THREE cylinders (1, 2 and 3), plus running rich and lean again. Two coilpacks in stock so replace 1 and 3 (I'll be honest - I just wanted new bits in the car for peace of mind!). Car drives like THE BUSINESS immediately after and for a couple of days. Now it's back to playing up a little (albeit not as badly as before). Now got slight spluttering and switching between running rich (14mpg) and running lean (34mpg). I don't want to replace another coilpack if it's just going to mask a greater problem - I'd rather find out what's actually wrong and get it sorted.Gonna book it in for a couple of days of data logging but wondered if anyone has any pointers please? My technician is seriously talented and has suggested it might be a one-way valve sticking open, but it would help save time if anyone has encountered something similar.Again, sorry for the long post, and thanks to anyone who can help! Edited February 23, 2014 by burns burns 1 Link to post Share on other sites
mattvr6 133 Posted February 23, 2014 Report Share Posted February 23, 2014 Maf sensor is a probable cause will also make ur gearbox act funny Sent from my iPhone using Tapatalk Link to post Share on other sites
burns 1 Posted February 23, 2014 Author Report Share Posted February 23, 2014 Thank you for that. He did suggest that and said it might cause the faults that have been logged. Will get it booked in and ask that That's the first point to investigate - cheers! Link to post Share on other sites
mattvr6 133 Posted February 23, 2014 Report Share Posted February 23, 2014 No probs id also scan the gearbox make sure there's no faults logged for that aswell Sent from my iPhone using Tapatalk Link to post Share on other sites
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