1999 Boxter smoking after starting
#2
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Sounds like your AOS may need some attention. Try here: Inspecting the AOS.
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#3
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Agree with comment above, most likely your AOS (Air/Oil Separator) is on the way out. My 1999 Boxster Base exhibited the same symptom, blowing white smoke upon startup or after a spirited drive. Changed the AOS, no more smoke.
#4
Rennlist Member
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FYI: AOS is a fiddly, but manageable DIY. There are some good YouTube videos about it.
#5
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True, the Boxster AOS replacement is somewhat of a PIA. particularly the hoses/clamps at rear bulkhead, but at least its not as dastardly as the 996.
The following 2 users liked this post by Weazer:
Cheekybird (10-06-2021),
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#6
Racer
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Could someone point me to a good video or DIY thread on replacing the AOS on a 986. Everything I'm seeing on Youtube shows guys breaking stuff and the videos are incomplete. I've got the job started and it's looking like a real PIA. Also, the videos are not consistent on what needs to be moved out ot the way and how to do that without breaking stuff, in order to do this job.
#7
RL Community Team
Rennlist Member
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Another problem with AOS DIYs is the early M96 AOS is different than later M96/M97 AOS.
In the 996 the change was 2002. (996.1: M96.01-M96.02 to 996.2 M96.03)
I'm not certain when the change happened in the Boxster.
My 2005 Boxster M96.25 had the newer style AOS.(Similar to my 996.2 M96.03)
The AOSes are similar oil & coolant hose-wise, but they attach differently to the block and head.
In the 996 the change was 2002. (996.1: M96.01-M96.02 to 996.2 M96.03)
I'm not certain when the change happened in the Boxster.
My 2005 Boxster M96.25 had the newer style AOS.(Similar to my 996.2 M96.03)
The AOSes are similar oil & coolant hose-wise, but they attach differently to the block and head.
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#8
Racer
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Another problem with AOS DIYs is the early M96 AOS is different than later M96/M97 AOS.
In the 996 the change was 2002. (996.1: M96.01-M96.02 to 996.2 M96.03)
I'm not certain when the change happened in the Boxster.
My 2005 Boxster M96.25 had the newer style AOS.(Similar to my 996.2 M96.03)
The AOSes are similar oil & coolant hose-wise, but they attach differently to the block and head.
In the 996 the change was 2002. (996.1: M96.01-M96.02 to 996.2 M96.03)
I'm not certain when the change happened in the Boxster.
My 2005 Boxster M96.25 had the newer style AOS.(Similar to my 996.2 M96.03)
The AOSes are similar oil & coolant hose-wise, but they attach differently to the block and head.