The zinc in the 2 stroke oil will build up on the injector nozzles and affect the spray pattern and efficiency of the injectors and bhp will be lost . Maf sensor , and map filter cleaning , a clean air filter all very simple jobs but need the maf sensor cleaning spay as not to damage the sensitive parts, map filter can be cleaned by spraying carb cleaner then brake cleaner spay through till clean fluid comes through then blow through with clean air to get rid of any fluid, and a clean fuel filter , and egr clean will differently help . A full egr clean down through including inlet manifold is a full day job and very fidderly and messy if very dirty to say the least .
OK many thanks for that! I am almost certain that the sound is caused by vibration and involves plastic/sheet metal rather than engine parts as described in that thread! It is extremely specific to 1400-1600 rpm so that points very clearly to the air inlet ducting/wheel arch interface as described.
Been using a 1/200 mix in my 2003 LC4 for 5 years. Now on 150k and purring nicely. There has been lots of research by Merc. and BMW and as long as you use basic mineral low ash oil it has been proved to be beneficial.
There are pros and cons the use of 2 stroke oil was first started been used in diesel engines when most of the sulfur was removed from diesel for pollution reasons ,the sulfur added to the lubricant of the fuel, and old non direct injection diesels benefited from using 2 stroke low ash mineral oil 1/200 , now euro diesel which is used in all EU nations has a lubricant added to the fuel that more than compensates what sulfur lubricant had . 2stroke oil although low ash is relatively high in zinc which is well known that it fouls the injector nozzles on direct injection diesels . Fuel additives that are added to help clean injectors could go someway towards cleaning the injectors , but I don't know if it will remove the zinc from the tips of the injectors which will affect the spray pattern , If you google ,( the facts of the use of 2 stroke oil in diesel engines) you will find a lot of info on the subject . I purchased 10 litres of low ash 2 stroke mineral cheap I paid £28 for it, as I too was planning to use it in my 120 lc, but after studying the facts I decided not to . I now just use it in my garden tools so its going to last me a hell of a long time before I use it up .
You can get full synthetic 2 stroke oil with zero zinc which is not cheap like mineral 2 stroke , mineral 2 stroke is for low tec 2 stroke engines like small generators and garden tools , don't know if semi syn is zinc free best check with the maker , the cost of making it zinc free might make it have no savings in price against full syn which is a superior product , and as far as I know not all fully syn 2 stroke oil is zinc free, only the top spec oil for ultra spec 2 stroke engines . which make it not viable to put it in a diesel engine . Also it is said fully syn 2 stroke oil does not mix well with diesel fuel so its a bit of a catch two situation . Only direct injection systems suffer from the zinc problem because the injector spay tip is in the combustion chamber , non direct injection dont get the zinc baking on the injector tips as they run at a much cooler temperature .
