Go Back   986 Forum - The Community for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical Chat

Post Reply
 
LinkBack Thread Tools Display Modes
Old 07-28-2014, 01:22 PM   #1
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
Throttle Response and Failing AOS

Last week I had some time to get into my engine for a few things. I had the left and right plenums open and noticed that they are wet with oil and the pooling in the right maybe up to 1-2mm depth. I would assume that the AOS is on its way out from this.....especially when I was I there attending to an oil filler tube leak. Oddly, last time I checked I had very little suction on the oil filler cap. No smoke. The thing seems to be stealthily failing..

Would this situation affect proper throttle response from 3-4K ? I would think it would if you trying to combust too much oil/vapour. I have been chasing this problem and I think this maybe it.

Is there currently a better motorsports AOS that can go in a 2000 S ?

__________________
986 00S

Last edited by jaykay; 07-28-2014 at 06:50 PM.
jaykay is offline   Reply With Quote
Old 07-28-2014, 03:24 PM   #2
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,709
Garage
Quote:
Originally Posted by jaykay View Post
Last week I had some time to get into my engine for a few things. I had the left and right plenums open and noticed that they are wet with oil and the pooling in the right maybe up to 1-2mm depth. I would assume that the AOS is on its way out from this.....especially when I was I there attending to an oil filler tube leak. Oddly, last time I checked I had very little suction on the oil filler cap. No smoke. The things seems to be stealthily failing..

Would this situation affect proper throttle response from 3-4K ? I would think it would if you trying to combust too much oil/vapour. I have been chasing this problem and I think this maybe it.

Is there currently a better motorsports AOS that can go in a 2000 S ?
No MS AOS is made for the 2003 up style AOS engines.

AOS diaphram degrades & begins to tear. Oil in cylinders begins to foul the spark-plugs.

Check your plugs starting on Passenger side.
__________________
OE engine rebuilt,3.6 litre LN Engineering billet sleeves,triple row IMSB,LN rods. Deep sump oil pan with DT40 oil.
BYprodriver is offline   Reply With Quote
Old 07-28-2014, 06:48 PM   #3
Registered User
 
Join Date: May 2011
Location: Miami florida
Posts: 1,591
Hmm. A bit of a poser. I have the same year. If there's not a lot of vacuum at the oil filler, I don't think it's the AOS. Ive had lots of oil when i took off the plenums, so I don't think that's the problem.

Any codes? Get back to me if you have a dura metric, there are some values you can look at to check for common problems.
__________________
Current car

2000 Boxster 2.7l red/black

Previous cars

1973 Opel Manta
1969(?) Fiat 850 Convertible
1979 Lancia Beta Coupe
1981 Alfa Romeo GTV 6
1985 Alfa Romeo Graduate
1985 Porsche 944
1989 Porsche 944
1981 Triumph TR7
1989 (?) Alfa Romeo Milano
1993 Saab 9000
san rensho is offline   Reply With Quote
Old 07-28-2014, 06:56 PM   #4
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
No cel and no codes stored on the last durametric (enthusiast version) scan. I would have thought the wet plenums would mean improper air oil separation.

Please let me know what values to check....maybe MAF and O2 just to start ....would need to know the acceptable ranges
__________________
986 00S

Last edited by jaykay; 07-28-2014 at 07:00 PM.
jaykay is offline   Reply With Quote
Old 07-28-2014, 07:02 PM   #5
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
Quote:
Originally Posted by BYprodriver View Post
No MS AOS is made for the 2003 up style AOS engines.

AOS diaphram degrades & begins to tear. Oil in cylinders begins to foul the spark-plugs.

Check your plugs starting on Passenger side.
Okay I had a feeling I was out of luck with my year...will pull a plug

Thanks !
__________________
986 00S
jaykay is offline   Reply With Quote
Old 07-30-2014, 09:21 PM   #6
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
Okay I have just finished about three hours running time: highway, country and gridlock......yah TO has it really bad right now

I pulled the oil filler cap to check for suction and there is enough to hold the spring loaded oil filler funnel until I knocked it against its upward stop....so perhaps approaching the suction force of an old worn out vacum cleaner and I can get a hissing noise happening by hold the cap close. Is this normal suction? I would say no myself...

Also covering and uncovering the the filler funnel a few times disrupts the idle of the engine and one can feel the engine react to the vacum change. Again, not knowing the inner workings of the AOS, it feels like the AOS is packing up. Anyway it's odd that most only see the smoke screen and then they know

How would this AOS condition affect throttle response??
__________________
986 00S
jaykay is offline   Reply With Quote
Old 07-31-2014, 03:33 PM   #7
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
Oil Separator (High Performance Version)
- Boxster S Special Edition Convertible (2004) Note: Also use (Qty.) (1) 996 107 947 00 line.
- Boxster and Boxster S Convertible (2000-04) Note: Also use (Qty.) (1) 996 107 947 00 line.
Brand:
[More Info]
Rating: Part Number: 996-107-926-00-M100

It would appear that a high performance AOS is available for from Pelican and if you check it out the listing seems to indicate that it will fit the above. Is this correct??
__________________
986 00S
jaykay is offline   Reply With Quote
Old 08-05-2014, 08:27 AM   #8
Registered User
 
Brad Roberts's Avatar
 
Join Date: Aug 2004
Location: Alta Loma, CA
Posts: 1,334
The performance AOS *only* works on the Boxster 03 and up engines. It has to do with the oil return tube Porsche installs in the engine. The earlier 97-02 blocks? the AOS has a penis that goes into the block. 03 and up is completely different.
__________________
Engine Builds, Transmission Builds, Engine Conversions, Suspension Installs, Suspension Tuning, Driver Coaching, Data Acquisition, Video, SCCA/PCA/POC/NASA/GRAND AM/ALMS.
We have worked with amateur and professional drivers for over 26 years. In house machinist, In house fabrication. Our cars, our parts, our engines, our transmission's run nationwide at events every weekend. We work side by side with industry names developing parts.
Brad Roberts is offline   Reply With Quote
Old 08-05-2014, 12:53 PM   #9
Registered User
 
jaykay's Avatar
 
Join Date: Sep 2009
Location: toronto
Posts: 2,668
Okay, thanks! Now I know for sure the listing put some doubt in me. Errrr em.... If the penis does not fit it usually means things are not going to work as they should

__________________
986 00S
jaykay is offline   Reply With Quote
Post Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 04:08 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page