Evil, thanks for posting back with some more info. Sounds about right. Direct injection engines can suffer a bit more from this as the exhaust valves do run a bit hotter than indirect injection. That means tolerances in the valve guides are pretty slim and could be a problem for some engines if that isn't fully taken into account. I suspect the new head has valve guides that have a bigger clearance to allow more lube and tolerance to the high heat. Problem solved.

Edited 5 July, 201312 yr by Estate Man

Yes it's likely the last we'll need to wory about it with this car, but if you google TSI and burned /burnt valves you'll find there are plenty of Polos with the same engine and the same issue. maybe it was the early iteration of the engine - I don't know. This car is a low mileage 08 year model. Could be it is long ago sorted except for the earlier engines that are running about. I have no idea when the engine came into use. Anyway - new head means latest valves and guides.

 

Thinking about my 1.4 TDI PD model - I'm thinking that diesels will have cooler running valves theoretically, since the extra expansion extracts more work out of the combustion gasses before letting it out. I am hypothesising that diesels will be less prone to valve failure, albeit that the PD engines need careful oiling with the narrow cam lobes etc. All engines will have their own failure issues. 

 

I had been thinking he'd be well off with the chain driven cam shaft on the TSI. I'm sure he will be now. )

Yes, the diesels engines run around 25-30% cooler at combustion. Exhaust gases are considerably cooler too than in modern petrol engines. The cam rockers have rollers on the end to reduce friction and wear so dont' worry about those. As long as you stick to the fully synthetic 505.01 or 507 spec oils you can't go wrong and the engine will live long and prosper. I thought the TSI engines came out in 2009, but I may be wrong. It wasn't available in mid 2008 when I bought my first Skoda Fabia 1422cc PD diesel estate.