austin9111

Hi all.

I have a 1998 2.5 Boxster manual with 76,000 miles.

It smokes on startup (modestly, not like some of the plumes I see in some videos) and is leaving oil on the garage floor.

It has the original(?) AOS with the horizontal diaphragm body.

I am replacing it with a newer style(?) Uro with the vertically positioned diaphragm.

I have seen conflicting information on whether my original air intake-to-AOS hose also needs to be replaced because it will be too short for the newer style AOS.

When I compare my air intake-to-AOS hose to those for sale online, they appear to be the same. See the picture of my current hose below.

So, do I need to get a new hose?

I would hate to get the new style AOS installed, then discover I also need a new hose.

Any advice/insight on my hose situation would be most appreciated.

SilverFarmer

When I replaced mine, a 98 also, the part numbers were:
AOS 996.107.023.04
lower hose 996.107.147.55
upper hose 996.107.145.06.
I replaced the lower also as it was original and members on here suggested changing it as it gets brittle with age.
Hope this helps!

austin9111

Have the AOS, ordered the upper hose and the "preloaded" hose clamp, but not the lower hose.

Where does that lower hose terminate on the engine? It looks tough to get at on the AOS end, can't imagine what it's like at the other, buried end.

Starter986

About the lower hose... I do know that it can be a PITA. Thus, when I replaced my old AOS version with the new one I thought I could fabricate my own "new" hose". It worked, but looked like ****. I purchased the new hose, all good.

I do remember when removing the old AOS the lower hose connection to the AOS was kind of a pain. It is here where you'll want to exercise patience for if you break that lower hose you'll really be having o exercise patience putting in the new lower hose.

Slow and steady wins that race.

austin9111

Yes, definitely slow-and-steady.

I learned that the hard way recently on my wife's Buick Encore, which has the craziest PCV setup I have ever seen (and which failed): 1/3 of the PCV valve "function" is literally molded into the cam cover, another third is molded into the intake manifold and the last third is in a hose from the turbo to the intake. If it fails you need to replace the cam/valve cover AND the intake manifold AND the turbo-tointake hose, if you break it, which I did. And it was brittle after only 6 years old, not like the 26 year old hoses on my Boxster.

But as no one's commented on whether I need a new upper hose when going from the original 2.5L horizontal AOS diaphragm to the newer vertical style, I went ahead and bought one just to be safe.

Nickshu

The hose I would be most concerned about is the long one that goes from the AOS, under the intake to the left front corner of the engine. This one is most often cracked. It's very difficult to replace with the engine in the car, but can be done. The intake must be removed.

austin9111

thanks for the further warning.

I all the videos I've watched, the potential brittleness of the hoses -- upper and lower -- didn't seem to be an issue, but given my recent experience with my wife's car, I will be extra vigilant when approaching the lower connector.

austin9111

I will keep my antenna up on this one . . .

twolilsnails

Yes, to answer the question you actually asked. New hose is required... the original one is going to be ever so slightly too short to reach.

austin9111

Thanks. Once I get the new upper hose (going to be careful and assume I don;t break the lower hose), I am going to jump in