Considering Direct injection petrol engines, as we now are here, a few years ago I'd have said "Yup, oil catch cans, definitely beneficial, providing you buy a properly constructed product" (there's a lot of cheap and poor product out there). Now though I'm not so sure. Oil catch cans will probably have some beneficial effect and slow down build up but I don't believe them to be the whole answer when considering this particular and unique
problem.
I'm very interested in this
problem and have been following up every clue I unearth. One of the best and simplest to understand is Andy Archer's article on the Oilem website. Look here:
https://www.oilem.com/blog/turbo-fu...irect-port-injection-carbon-build-up-problem/ I think you'll find it very interesting.
I'm not a great believer in additives generally - especially not oil additives - but I decided to give their Archoil AR6900-P MAX a go on the basis that "every little bit might
help". I buy it from Powerenhancer which seems to be their sales outlet (I've also had some excellent prices for quality oils from them too). I bought the
Ibiza new in spring 2016 and gave it 6 months (probably around 3,000 miles) of running before I started with the additive as I wanted it to settle in without possibly compromising anything. I'm now approaching 25,000 miles (and about half way through my third one litre bottle of the additive) and notice no difference in performance and general engine running when compared to when new. I'd been intending to remove the inlet manifold/charge cooler and inspect the inlet tracts at around 5 years/30,000 miles but she's running so well and returning exactly the same fuel consumption figures as when new that I'm probably going to wait until she turns 50,000 (I'm a great believer in "letting sleeping dogs lie"). I'm not expecting the product to completely stop carbon build up to occur but, for what it costs, if the product substantially slows down build up I'll be very pleased and consider my money to have been well spent.