>> I understand all of this -- makes sense to me. But >> where does the evaporated moisture then GO to? I >> mean, it probably never really leaves, does it? >> The point is then to just always get your engine >> hot to prevent the water from staying in the oil >> and emulsifying with it, right?
>> I think they make oil additives to reduce water in >> oil, yes? Are these worth it, or just frequent >> enough oil changes to avoid water? This is a subject that should have no particular revelance to the 2.7L engine. All internal combustion engines will exhibit this crankcase moisture problem. The moisture actually comes from combustion gasses leaking past the piston rings -- a normal phenomenon. H20 is a byproduct of combustion. Wonder where that moisture dripping out of your high efficiency furnace is coming from? Its the same concept. With today's much more advanced engine controls, its not as much of a problem, but typically an engine runs much richer when its cold, thus burning more fuel and producing greater amounts of water. Probably 99.9% of it goes out the exhaust pipe, but that last .1% leaks past the piston rings where it will stay until it evaporates. Unburned gas also joins that mixture. In addition, when its below zero outside, the moisture within the hot combustion process condenses instantly on the cylinder wall, which is still very cold yet. The piston rings come up, grab a little bit, and pull it into the crankcase. We're talking very small amounts, but it all adds up. An engine just sitting there with moisture accumulated in the crankcase (an almost-perfect airtight seal) will never allow that moisture to escape or simply dry up. Water also settles to the bottom, so it isn't gonna dry up very well like that. So, via simple physics, that moisture (and gas!) will dry up (vaporize) MUCH faster when the engine is hot, and since the engine is burning much more efficiently, there is less moisture being produced. Where does it evaporate to in this almost air-tight seal? It is evacuated via the PCV system. Its constantly creating a small flow of air through the crankcase to expel the harmful combustion byproducts. The original purpose of the PCV system was to allow the engine to suck hydrocarbons into the intake to be burned rather than vented to atmosphere. It sucks the gaseous form of water, too, and expels it. Also, hydrocarbons make engine oil acidic, and it will literally eat things like bearings. FYI, I have yet to see a single 2000 or older 2.7l engine without a collapsed / deteriorated PCV hose. Which means the pcv systems were not working. Contributing to failure? maayyyybeeee. Hence the reason for 3 mo. or 3,000 mile oil changes, whichever comes first. For most people, if you don't drive 3,000 miles in 3 months, it means there's a lot of short trips involved and lots of impurities in the engine oil. Quality lubricants will help combat these negative factors. Avoid oil additives, and just use quality engine oil like valvoline. Great engine. You just have to do the regular maintenance like you're supposed to with anything. Oil is cheap. Engines are espensive. Its a quiet engine. If its making noise, get it checked out right away. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------ Yahoo! Groups Sponsor --------------------~--> Everything you need is one click away. Make Yahoo! your home page now. http://us.click.yahoo.com/AHchtC/4FxNAA/yQLSAA/46t0lB/TM --------------------------------------------------------------------~-> Web: <http://groups.yahoo.com/group/dodge_intrepid> Subscribe: <mailto://[EMAIL PROTECTED]> Unsubscribe: <mailto://[EMAIL PROTECTED]> Moderator: <mailto://[EMAIL PROTECTED]> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dodge_intrepid/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
