GDI Engines and Coking Valves

[SRGTD]

Yes, those leasing for a period of three or four years really won't find this concern at the top of their list.

For those who have bought, or are buying, with their own cash, I'm surprised that nobody's really saying much about it.

Maybe they’re unaware of the potential issues. Or alternatively, if they’ve given it any consideration, they may just accept the cost of a potential engine decoke at around 30-40k miles as ‘just’ another maintenance cost (a one-off cost for most, based on average UK length of car ownership - see link below), in the same way that changing a cam belt and water pump would be, and is more likely to affect the second or third owner of a car.

https://www.am-online.com/news/mark...ownership-now-less-than-two-years-says-tootle

For some, the symptoms of carbon build up might not be pronounced, and owners’ cars displaying only mild symptoms of some or all of the tell tale signs (rough idling, hesitation on acceleration, intermittent misfire), may not bother to do anything about it, or in the throwaway society we live in, they might just sell their car and buy a new(er) one!

 

[RUM4MO]

I think that I've said this already, but once again, these turbo charged petrol engine will cover up a lot of the effects of coking that people are liable experience due to the forced induction, yes there will be a loss in output slightly but probably not enough over say 60K miles to cause uneven running.
The main sort of GDI engines to suffer have always been the normally aspirated ones, from my VW Group motoring forum reading, that means the 4.2FSI engine etc in RS models of Audis - demanding lots of the output potential from them as they get older has left some owners feeling a definite drop in output and they have had to get the walnut shell treatment carried out at higher mileages.

I'd still rather have a spot of port injection though to stop this happening.