Cylinder 3 ??? Polo 1.2

[ihendry76]

Hi ALL
Polo 1.2s 54k 2006
I've had engine management light on and the car spluttering.
I changed 3 x coil packs and plugs
then compression test revealed #3 down - very cracked burnt valve, had the valves replaced.
back together but still spluttering same - changed injector, but still same.
then changed the ECU today ..... and STILL the same.

when spluttering, I remove the #3 coil or injector wiring and nothing notable changes. (fuel and spark all Good)

Anyone with any ideas Please ???

[iichel]

Go to a proper garage?

[RUM4MO]

Well, if that garage has removed the cylinder head and refurbished that assembly so that it is now in good condition, then that might suggest a wiring problem to either the cylinder 3 coil or its injector.

I just hope that that cylinder head assembly is still serviceable and not just got a new set of valves in it, the holes in the cylinder head wear a lot I've heard in these engines, so was the observed wear in spec and acceptable - or did they just replace all the valves and now they are "flapping/wobbling" around in valve stem holes that are too big for them - and that is why one of the original valves failed or ended up with damage?

What sort of garage are you using for this work?

[ihendry76]

thanks the work has been all been carried by a senior VW technician, albeit from his own garage during the evening,
All valves, guides and seals changed.


wiring has all been checked out by Auto electrician with diagnostics.