can anyone tel me what this hose is for and is it necessary

 

its the line that goes into the air intake hose (i have seen similar things on older cars where some of the engine exhaust was pushed back into the intake) never a fan of that

 

It's actually the return from the cam-cover pressure system. It goes from the right side of the engine to the intake between the air filter and the throttle body.
Check out threads on Oil Catch Cans--lots of relevant information.

 

ok so i have read up on it and it doesn't seem like its needed can you direct me to any posts that might say if there are hazards of not having it hooked up to the air intake???

 

You may pollute the atmosphere and harm the ozone by not having it connected. As far as harming your engine No. It is the breather non pressure side of the complete PVC system. If you choose not to keep it connected run a line to the lower part of the engine for venting and cap the CAI hose so you do not get any unfiltered air in the intake system. If you do not drive you Mini long enough to get a good operating temperature then this procedure is not recommended.

 

ok thanks that was very helpful

 

It is absolutely needed. DO NOT CAP IT OFF.

If not connected to the air intake do as Nitrominis says & add a filter, you don't need any contaminates in the top end ( even though it would not be much ).

 

Are you saying that the breather side draws air in? If it is on your Mini you got some internal engine problems going on. LOL you may want to check out your facts on how a PVC system works. LOL The breather side of the system does not pull air into the engine or crankcase. When you are under a load there is no vacuum and the PCV valve closes. The pressure in the crankcase is then relived through the breather tube into the intake system. Likewise when you are off the gas or idling there is a vacuum and the pcv open and allows the crankcase air to be pulled into the intake system. In some heavy duty and early year application of cars and trucks it was simply vented into the air. With emission regulation for most engines operated in the US they have to have a closed system. In my case I run an evac system into the header collector and do not even run a pcv system. But prior to that I ran a small K&N filter on the pcv valve and a clear tube on the breather side down the side of my engine. This is the tube you have in question.

 

right now i have an intake i installed and the tube is just hanging there
im not going to plug it

figured i dont want hot air forced back into the air system

 

this is my air intake

https://www.northamericanmotoring.co...d.php?t=147072

 

PM sent

 

Cap at intake hose not the breather tube. Extend the tube out the bottom of the engine compartment.



PVC side(right) looks like this.

 

The pic the OP posted Is not showing the PVC side. The nipple shown, pic, is the only fresh air source for the crankcase. I'll bet the PVC side has the OE in place.

Your setup deletes the need for both sides of the valve cover to vent.

Had to go out for a while before finishing this post.

The OE is still in place RE: post 10

 

now is there any advantage to having the little filter on there over stock?

 

If I had the same setup as Nitromini I would not get a state inspection sticker.

The nipple that you have, the picture in your first post, needs a filter on it or connect to your intake. You can use a small K&N like nitromini's