MinerWilly

Morning all, my 1.4 tsi 62 plate (my taxi) developed about a month ago an ever so slight whistle when accelerating. I spend 10 hours a day in that bugger so noticed difference right away! Performance seems not too have changed but this week I twice had a had an engine misfire code P0304 and a P0302. Could be that spark plugs and or Coil Packs need looking at but because of the initial whistling thing I was thinking perhaps it's a vacuum leak. I don't want to spend a fortune and a lot of time on packs etc (selling it in 3 months) if it is just a vacuum leak. Not really sure which pipes I should be looking at but I did notice this splatter and wondered could this be the culprit and does anyone know where its coming from. Thanks all.