hi ive just been looking at a missfire on a vw polo 04 1.2 3cyclinder engine bmd,its looking like sticky or burnt out valves is this common,whys it caused and whats the best fix thanks in advance

 

Had one of these in, same symptom, turned out to be injector!

Is the engine management light on? What codes come up?

If it comes up saying what cylinder is misfiring, clear the code, swap a coil pack, see if the code moves onto the next piston. If it doesnt, do the same with an injector.

If that still doesnt clear anything up id say whack a full set of coil packs in it before you start playing with valves!

 

Had this and it was coilpack. Engine was vibrating like fook!

 

you need to determine if its sparking, getting fuel, (if not spark or fuel is the ECU sending signals to do so) and is the cam timing right, as they jump chains like fuck

there is nothing on these engines that is "most common"

i have seen more chains jump than coilpack failures and injectors (black with yellow band) are also just as shocking for failure, coilpacks are actually very reliable on these

 

Wasnt there a recall on the injectors?

 

I know the injectors are very common on these!!!

 

They do suffer from getting burnt valves last one I had to do was only 30k miles fsh was fine with a few revs but lumpy tick over/lumpy at low revs.

Wierd how it affects them as have had them at 100k and they've never had the head off and still running sweet.

 

Just do a leakdown test for the valve issue.