Turbo Timing... not needed in Nissan Silvia (nissansilvia.com) Posted July 21, 2003 Ok, the oil wont cake, but those few weeks before your service, what about all the crap and sh*t thats in your oil. All the carbon + crap thats gotten past your rings into your oil will cake on your bearings. Its interesting you brought up that point. These external sources, mostly water vapour and tiny particles are trapped by the oil. The oil then starts to lose its lubricating properties with more buildup. The only way to combat this is to change your oil regularly and keep a nice and fresh oil filter in your car. Also the "crap" is burnt off with higher temperatures which is one of the ways the engine actually relies upon (heat) to get rid of water vapour. Synthetic oil is great...... but its not immortal. You must change your oil and oil filter often. The more often the better.