| Re: Got a small but pesky timing cover crank seal leak so says my shop |
Subject: Re: Got a small but pesky timing cover crank seal leak so says my shop by bogus on 2010/12/8 20:18:03 oooh... I see some misunderstandings on what PCV does... Positive Crankcase Ventilation was one of the first emission controls placed on engines come 40 years ago. The idea is simple, close off the internal engine vapors so that the gick doesn't just float into the atmosphere. All the vapors, from combustion gasses to the vapor off the motor oil itself are captured and burned off. Fresh air is introduced, under vacuum pressure, to draw the gick through. When the PCV is blocked, the pressures can rise, creating leaks. Also, because engine vacuum is used, it can cause run-ability problems when an external leak is created. Make sure all the vacuum lines are good and that the hoses that run the system are good. Oh, and the valve itself! If you are running synthetic oil, it does not mix with gas in the same way dino oil does. It kind of encapsulates it and it gets trapped in the filter. The vapor isn't strong enough on its own to harm the oil, but during startup, the fuel that blows by the rings or what sits in the combustion chamber will do damage. And it is that which is captured by the synthetic oil, deposited in the filter and once the engine reaches op temp will ultimately get burned off. Dino oil will simply break down over time, some fuel will get burned off, but for the most part, the fuel will bond with waxes and thin down the oil. This is one reason why synthetic oils are really better. Oh, and just so you all know, the real difference between synthetics and conventional oils is the absence of the wax. Get rid of the wax, good things happen! Those gasses are VERY toxic, and the act of burning them off has been very instrumental in clearing our air pollution problems. |
