94T/A5.7LT1

iTrader: (1)

Can anyone tell me what its purpose is besides vent the crankcase? it seems to be leaking oil where it connects to the valve cover and where it connects to the throttle body, dont know if its suppose to have oil in it or i got other problems. thanks

trilkb

iTrader: (4)

pretty common problem, its an emissions thing. I capped my TB and put a breather on the valve cover. The tb in theory should suck on that line and then the line will act like a vaccum. With nothing sucking on it, id say your ok.

Never made sense to me though why one side needed one and the other didnt though, not to put down GM's awesome name (take that how you want to), but i dont think the lt1 was designed and engineered to direct crankcase pressure all to one side of the engine lol.

RamAir95TA

iTrader: (2)

The tube is not there to provide a vent for crankcase gases. It is designed to allow suction for the PCV system. The PCV valve pulls out crankcase gas while fresh air is supplied via the hose from the throttle body to displace the removed gas (similar to the fuel tank vent valve - it allows air to escape when you fill the tank and there is less volume of air).

It does not always work this way and is engineered to work both ways. At times of low manifold vacuum (WOT, etc.) the PCV valve cannot keep up, and crankcase gases reverse through the tube and deposit into the intake manifold. This feature ensures that all of the crankcase gas is recombusted. However, upon reversion the gases bring with them a fine oil mist (which is what you see most people complaining about when they take off their throttle body and are surprised to see oil). The valve cover is baffled to help prevent this, but some oil still gets by. This is why we invented catch cans (you can use on both the fresh air supply line AND the PCV hose (early models need to make their own, or convert to a 95+ line).

One could also make the argument that the air supplied by the tube is MAF-metered, so removing the tube would have a very small, negligible impact on PCM calculations, but this has never been proven or dis-proven.

If the grommet is leaking, just replace it.

shbox

Obviously, you don't know how the system is supposed to work. Joe's explanation should help.

trilkb

iTrader: (4)

obviously, you are correct. I probably shouldnt have responded.

94T/A5.7LT1

iTrader: (1)

Were can I get a replacement hose? Mines all cracked at the connection ends. I thought about just getting some rubber hose but it has formed bends in the original one. Thanks everyone for the replys.

FormulaJoe

iTrader: (5)

What effects would just slapping on a filtered breather and closing the TB nozzle have? If any?

RamAir95TA

iTrader: (2)

This was mentioned in my first post. The only benefit is if you're looking for a quick fix for a leaky hose or fitting (or if you think oil in the throttle body is harmful). If the system works there's no need to change it.

wrd1972

iTrader: (12)

I have a little filter (forgot the name) that snaps into the valve cover and then connects to the hose running to the TB. It can be had at any parts house for about $5.00 and is well worth it. It keeps all of the oil out of the top of the TB. I also have a catch can on the other side and it reduced the oil in the plenum a great deal but not completely. The PCV system has merit and should not be deleted on a regularly driven car IMO. It reduces moisture and oil break down within the engine.

wrd1972

iTrader: (12)

Looks decent to me. I am running the one from WS6store.com