grads132

if the ecu doesnt light up could there still be a fault with the engine especially regarding rough idle

recently bought a fabia2 1.2htp fantastic car except no warning light on dash and had 2 mechanics take a look using there diagnostic machine and cant find a fault.but here is the problem, when i come to a stand still the revs go from 800 rpm down to 500-600 rpm then back up and it will go up and down until i apply a little accelerator then it stops,sometimes it wont do it one day and then it will do it 3 or 4 times in a one mile run it also does it when the engine is cold and hot but more when hot i would say.somebody has told me to take it to a skoda dealership and let them stick it on there diagnostic computer and others say i would be wasting £80 as it will sill say there is no fault till the ecu light comes on dash.it has 3months warranty with asecond hand dealer so it is more for peace of mind than anything else,has anyone else experienced something similar and what was it.any advice would be appreciated.

hi all,i recently bought a skoda fabia2 2007 1.2htp,the car is a fantastic car except for one niggly thing. when you are in neutral or are coming to lights,stationary traffic etc and slowing right down or are at a standstill the revs will go from 800rpm down to around 500 or so(not enough to stall)and then go back up and it will keep going up and down until you put your foot on the accelerator a little.it doesnt do this all the time sometimes it wont happen for a day and then it will happen two or three times in a 1 mile run.it happens with a cold and hot engine but more when hot.i have three months warranty with the engine and gears it has been to two mechanics and put on there diagnostic machines and checked over(dont know what type machines)and because the engine management light isnt on they say that they cant find a fault.my friend who is a mechanic said that a skoda dealership will be able to find the fault using there computer diagnostic as it is better than a basic diagnostic machine used by mechanics.where as the second hand dealer i bought it from says that the mechanic he uses used a top of the range diagnostic machine,and paying skoda £82 for a diagnosis is a waste of time they might not be able to find a fault either which skoda agreed when i rang skoda.has anyone any ideas what the problem could be and how to rectify it just want peacer of mind thats all.many thanks