Originally Posted by O2Form
Think about it, why do engines use a PCV system.
Now tell me where the coldest part of the engine is?
the primary reason is pressure will build up in the crankcase, and that pressure has to go somewhere otherwise you'll blow out the front and rear main crank seals. Prior to emissions regulations you just vented it to the atmosphere.
The pcv valve allows the crankcase pressure to be directed back into the intake where it can be reburned which is more environmentally friendly.
The fact that you pull out combustion gases from the crankcase is more of a perk, the pcv system wasn't designed solely around that. And you could also make the case that since you are contanstly sucking air out of the crankcase you need a vent to allow air back into the crankcase, in doing so you're constantly supplying fresh air (oxygen) to the oil which actually helps oxidize it and that fresh air also constantly introduces moisture into the oil.
the coldest part of the engine is the inlet to the water pump, after the coolant has cooled in the radiator.
dude, the heads are one of the hottest places in the engine, that is why you see on sludge & varnish prone engines all that muck under the valve covers. It's also why the coolant temp sender is installed into the water passage in the head.