wtf is this ??

[img=http://img176.imageshack.us/img176/5765/d1915jz5.th.jpg]

 

im thinking it's the EGR ... but ive heard that it was something about coolant ?? which makes no sense to me ..

 

I believe its the PCV = positive crankcase ventilation. Some of the combustion gases escape past the piston rings and end inside the engine. Those gases are vented back into the intake for another shot in combustion. This reduces emissions and releases the excess pressure build up.

 

i believe you are correct and this is where you would place a breather filter (my understanding for higher mod'ed cars not the fit)
this is an article i was showed someone please correct if i'm wrong

The Positive Crankcase Ventilation (PCV) system ventilates the air in the cylinder head to equalize the pressure built up in the engine crankcase. The fumes are vented into the intake system to be burned up along with the air and fuel mixture. Although this improves the car's emissions, this results in three problems. 1) The crankcase gases enter the engine along with the air and fuel, cutting down on the amount of fresh, clean air the cylinders receive. Although there's a very small amount, it's always better for fresh, clean air to enter the cylinders rather than engine gases. 2) The engine gases are hot, and will increase the temperature of the air in the intake manifold. Remember, for every 10° increase in intake air temperature, you'll lose about 1% of the engine's horsepower. 3) Worst of all, the fumes contain vaporized oil which coats your intake manifold. When the piston rings begin to wear, blow-by increases and will cause a back up, resulting in the fumes exiting out the fresh air breather tube... where air is normally suppose to enter. The oil in the blow-by fumes will be blown through the intake and coat everything from the breather tube inlet to the throttle body with an oily film. If you have a turbo, this will include the intercooler and turbo. As the oily film builds up, a substantial decrease in performance will occur, including engine problems such as low idling and stalling. Many Probes with over 100,000 miles on them suffer from excessive blow-by. After cleaning out my GT's intake system of a coating of oil and soot, I looked for a solution to this problem, short of replacing the piston rings. Although a higher flowing PCV valve is usually recommended at this point, it's not a cure. The solution turned out to be reverting the engine to a PCV system from older cars. Older cars took in fresh air through breather tube filters. Removing the breather tube intake from the engine's intake system and placing a filter on the end instead meant that the oily gases would no longer be able enter into the engine's intake system.

 

Its just a crank case vent hose. Its off the valve cover. In short, that hose is using the sucking force of the motor (air intake, TB, and so on) to relieve pressure from the crank, rods, piston rings.... You know.

You do not want to plug that house. Also do not add pressure/air going INTO the hose. For NA (Naturally Aspirated) cars you can either add a breather filter or plumb it back into the intake.

Turbo cars can run a breather, catch can, or some sort of vacuum system that actually sucks the pressure from the block out. Adding vacuum (NOT pressure) is good for a boosted motor. Way less stress on the internals.

 

Nexus, fithouston and Mx6GT89 are absolutely right.

 

Yes, it's fresh air comming to valve cover and the pcv is connected from pcv valve to intake manifold directly for having a suction(vacuum) in the IM when idle.