After nearly 2 years, I've finally replaced my AOS!
 

Well at about the 3rd month of ownership 2 years ago, I realized I needed a new Air/Oil Separator because of 2 reason; 1) Puff of blue smoke every month or so. 2) leaking lots of oil from the bellows tube/accordian tube at the rear of the engine.


Between the time i noticed and the day I finally replaced the A/O Separator I've had a bad vacum leak and idle became progressively worse as time went on. So I bought the newest A/O S and J-Tube... Reset the cars computer and started her back up and BAM....... smoothest idle I've heard & felt from this car in over a year. And i can feel alot of lost HP come back in the Hi RPM's that wasnt there due to the vacum leak. I've driven it 98 miles since i did the AOS replacement and no CEL's and idle is still smooth and always just acouple hairs below 800rpm mark on the dash.

I've also noticed that Im not blasting through fuel as quickly.

Replacement took me about 40 minutes counting placing the top in service mode and replacing all the covers when i was finished.... I also pressure washed all the year in a half of oil and dirt stuck to the right-rear side of the engine as a result of the leaky AOS.

Glad it fixed all of that for you!!

Sounds like a new car.

Carlos - any tips on how to do the job in 40 minutes? That's impressive!

First, Have a shop to your disposal that has a lift! Without that, your in for a fun time reaching under the car for those 2 bolts, hose clamp and lower AOS snap-on hose.


Also, i was trying to rush alittle so i can post a good time :D

wadda bastard- took mine to Porsche dealership in Burlingame- only cost $900 yay!

Ouch! I took my time and didn't have a lift and it only took me about 2 hours... maybe I should open up an independent shop? Sheesh.

My AOS was shot. Smoking got pretty bad and idle crept up from 600rpm to about a 1000rpm. After replacement all is good again. Cost was about $500 but had to replace oil filler tube that got broken in the process. Plastic was very brittle and a little piece broke and fell into the oil pan. Found a worm in the oil pickup screen. Very strange.

Where is this AOS located? Do you gain access to it from underneath the car or from on top? I thought I read somewhere that it was accessed from underneath?

Well you have to widdle your arm through the right rear suspension over and under the rear axle and remove 2x 10mm bolts, then unclamp the bellows/accordian hose from the engine, then unsnap the plastic hose that snaps into the side of the AOS.

Once your done with that, goto the top of the engine and unsnap the jtube and start pulling the AOS up out of the engine and move the wires and hoses out of the way with your other hand as you carefully pull the AOS up off the engine.

Dayum! talk about taking it up the @$$. You should've researched it on the forum before.

Can you replace the AOS with oil in the car or do you have to drain it out first? I just replaced the 9.75 quarts of expensive Mobil 1

-Steve

no need to drain the oil. The aos sits above the oil crankcase

I hope you meant to say you replaced the 9.25 quarts of expensive Mobil 1 oil. You don't want to over fill with oil lest you ruin your Cat's which are very expensive.

Thanks CJ. I'm planning on replacing mine in the near future - next several months.

Regarding the number of quarts. I fully drained my 2001 S and according to the dip stick it took 9.75 quarts to refill. The oil gauge on the dash was one tick below full which is what I read on this forum as the full mark.

Thanks,
-Steve

CJB - what other symptoms did you have before replacing the AOS? I have smoke at start-up and a bunch of other problems that may be AOS related. When cold, the car has no power and it stalls/backfires badly with acceleration. Only when it's warmed up a bit does it come get a little life? I've "cleaned" the MAF with no luck. The problem started slowly over the last few weeks and is pretty bad now. My nearest shop is 4 hours West! Any ideas?

The AOS is a topic we'll be covering in our instructional video series that we'll be shooting in February... No more 900.00 charges to do this job from Porsche! I'll show you how to do it in less than 20 minutes, go over tools needed and share a few tricks.

Same thing goes for brakes, oil changes and all the other service related items :-)

^ sweet. those are all items I would like to address on my own with the boxster.

CJ, Thanks for posting. I think I am going to pick up a new AOS soon and swap out to old one this winter.

Jake, will this be available through your web site? What other goodies have you put together or is it all yet to come? I do NOT like working on my cars, but will take on whatever I think I can figure out just to not feel foolish with my money. I crave information and instruction because otherwise I stare at photos and wonder what I am looking at and just where is the gizmo that I am supposed to be seeing. :)

On a side bar, what are your shop hours? I think it would be cool to come take a peek, but I probably wouldn't be able to get away during the week.

Hey Goose, I had those same problems early on as well. Before replacing my AOS i went ahead and bought a new MAF and that fixed the weak cold engine issue but it still wasnt 100% when cold. After replacing the AOS, the cold engine power was back to normal and my idle was perfect and didnt hunt around when my AC was turned on.

'FYI I had to replace my new AOS twice, The first one still caused puffs of smoke and the idle steadily got worse, the second AOS actually sounded like it had a 9mm bullet firing out of it and my idle steadily got worse. Of Course the dealer gave me new AOS for free since this is a defect in the AOS they giving me so keep a close watch on my AOS for oil leaks and little bits of exhaust smoke cause you may get a defective unit and you can only replace it free if you report it as defective 30 days from purchase.

Thanks CJ, I will order the AOS kit and change it out ASAP. I have to order cost effective parts from the US to get good pricing, so it takes some time to reach me. Funny thing though, I pulled the MAF plug off for the second time and this time let the engine run for about ten minutes. Turns out the blurping and popping in GONE! I'm ordering a new MAF with my AOS! Thanks for the support and advice. :cheers: