What are the 2 quick connect hoses from the AOS lead to?
 

I am replacing the AOS in my 2001 Boxter and the bottom flex tube cracked in the elbow. It see it running across the intake but can't see the other end. Just got the car a week ago, and it the hose already had electrical tape around it.

That hose snakes under both intake manifolds and plugs into a fitting on the left side (drivers) of the engine near the front. It is really hard to see. If you take off the engine cover behind the seats you will see it under the a/c compressor. The photo shows the other end tagged with a postit note. http://986forum.com/forums/uploads02...1520267476.jpg

Yikes! Does it have stays holding it in? I ordered the replacement, but not sure what I'll have to remove to access it. is it a vent hose? What is it's purpose?

The connectors release by squeezing them. Once you receive the new hose you will see how they work. I know some who have broken the connector at the AOS have opted to cut off the hose somewhere near the AOS and splice in a section of hose and connector rather than replace the entire hose.

It goes to a positive crankcase pressure relief checkvalve

Yes I am familiar with the connectors, just wondering if there is anything attaching it in place. It is broken at the connector elbow at the AOS as well as the flex pipe where it attaches to the hard tubing under the manifold. Not sure if I can splice it.

So, does it release pressure into the AOS? I'm assuming the pressure is low since it is a fairly delicate plastic hose?

The rigid part of the hose is pretty tough stuff. Not sure if it is held in by any attachment under the manifolds. I'm also not sure whether there is pressure vs vacuum in the hose. I thought vacuum but not 100% sure.

I believe the hoses will be subject to either vacuum or pressure, depending on situation.

Under throttle if you have some blowby, you will pressurize these tubes. The vent valve this therefore intended to vent that. Typically though, the hoses should be under vac.

You should replace both hoses, they get brittle with age. And trying to splice them is the half as-sed way to go. Do it right or go home.

You will need to take the plenum cross overs off to get to the hose that goes to the left side. The crossovers are pretty easy to remove, you will need to remove the snorkel and some other stuff off to get the rear crossover out.

Get at least two cans of brake clean and clean out the crossovers, they will be oily. And a can of carb cleaner for the throttle body. Nothing seriously difficult if you don't break things as you take them apart. I have a vacuum diagram if you need one. (a really clear one.) I would budget a day for start to finish, tho it can be done in a lot less.

Brian, do you know which way to disconnect the end that goes to the front? I can't fit my hand through from behind the seat, and the air filter housing blocks the other direction. Any tips would be greatly appreciated.

Can you please share the vacuum diagram?

see if you can get to it from under the car. I recall being able to reach it from below.

Also helps if you have a friend who can push/pull on the hose while you pinch the fitting.

Thanks, I was wondering if that was the best way, or removing the fender liner.

you bet! Click the thumbnail:


https://s10.postimg.org/ysv3hgvmt/va...1480905094.jpg


A. I don't recall what it's called.
B. Vacuum tap on the left side of the front plenum.
C. Fuel pressure regulator.
D, E, F. Vacuum reservoir, junction, and diaphramed fitting in front of the AOS
G. Three way junction on manual trans cars, 4 way junction on Tip. with the additional hose going back to an electric vacuum switch for the trans coolant control
H. Vacuum check valve. Must be attached in that particular orientation.
I. Three way junction.
J. Electric vacuum control switch.
K. Resonance Valve on left bottom of the front crossover.
L. Vacuum source on the front, left crossover boot.

I don't recall where I got this diagram. I did not do the original work, tho.

I did mine while the engine was sitting on a pallet. I would suspect that undoing the motormount and lowering the engine might give you enough access. If you're replacing the hose & you can get a flat screwdriver under the retainer, you can break it to get the hose loose.

I've lost count of how many times I've lowered the engine in the past 3 months. Can do it in my sleep. Helps to drain and disconnect coolant hoses from the front of the engine. You can get to the motormount bolts with a 15mm deep wall, and extension and a ratchet. And if you decide that while you're in there to replace the motormount itself, you can get the back half off the engine with 15mm box end ratcheting wrench

That corner of the engine is a b-itch tho.

Thanks! useful info!