Ok, my little Ibiza ST has the 1.0 litre 3 cylinder CHZB 95 hp engine. As many will know this is one of the new generation of Direct Injection Petrol power units. It seems quite well established now that because no petrol travels through the inlet tract on this design of engine and therefore the detergent and cleaning additives in the fuel have no access to the inlet tract, carbon (from the oil in the breather and carbon in the exhaust recirculation systems - I'm talking generically, I don't think the CHZB uses EGR?) can, and does, build up in the inlet ports and accumulates on the back of the inlet valves to the general detriment of the running of the engine.
It seems likely that this problem cannot be totally eliminated without feeding fuel into the inlet ports (some VAG engines have 2 sets of injectors with one set injecting into the ports which seems to stop this) But I'm wondering if anyone has experimented with an oil catch can in the breather system to reduce the quantity of oil getting dragged into the inlets? If you have have you think it's had any very noticeable effect?
It seems likely that this problem cannot be totally eliminated without feeding fuel into the inlet ports (some VAG engines have 2 sets of injectors with one set injecting into the ports which seems to stop this) But I'm wondering if anyone has experimented with an oil catch can in the breather system to reduce the quantity of oil getting dragged into the inlets? If you have have you think it's had any very noticeable effect?