aos replaced still smoke

[andrewamberleigh]

I replaced my aos on friday, car didnt smoke as much on startup, got on it this morning after driving for 45 minutes @ highway speeds, and a Massive cloud of smoke again. Is it just burning some residual oil that could have been in the system, or should I start looking for motors? It still pulls very very strong (for what it is) so I cant imagine that it needs a motor. I am just mildly concerned.

[N41EF]

Did you clean out the intake when you replaced the AOS? Seem to remember some saying the failed AOD let oil pool in the intake plenum, which would eventualy have to go somewhere.

[logray]

Check all your hoses, perhaps you missed one and it was dumping hot coolant all over the place causing smoke. Of course, the low coolant light would start to flash, followed by...

[andrewamberleigh]

no loose lines

no cel or coolant lights.

No anything, runs great, just a massive ploom of smoke at the top of second. Felt like it bogged at the shift a little then smoked.

[logray]

Hmmm..... reproducible? or just that one time... if just the one time I might agree with N41EF that this could just be residual in the system that got burnt off during a "spirited drive".

[stonedagain]

no loose lines

no cel or coolant lights.

No anything, runs great, just a massive ploom of smoke at the top of second. Felt like it bogged at the shift a little then smoked.

Probably oil still lying around in the exhaust systen, mine was the same for a couple of days but it's fine now.

[kbrandsma]

I think a little white smoke for a while is typical. It is also a good idea when replacing the AOS to replace the "J" tube that connects from the AOS to the throttle body.

[andrewamberleigh]

I think a little white smoke for a while is typical. It is also a good idea when replacing the AOS to replace the "J" tube that connects from the AOS to the throttle body.

I replaced the oil fill tube, and the j-tube. After work it smoked more than ever on startup. Its really embarasing.

[andrewamberleigh]

At least it didnt break during a drag launch like my gtr did. That was totally embarassing. And I heard a loud echoing " I told you so" from my wife.

[Jager]

White smoke or blue smoke??

Test your new AOS, maybe it's bad... Happened to me.

[andrewamberleigh]

what is the best way to test the new AOS???

[logray]

Bad AOS =

Tons of oil behind throttle body.

Very difficult to pull oil filling cap off while engine running.

Edited August 23, 2011 by logray

[Jager]

what is the best way to test the new AOS???

As mentioned by Logray the cap is difficult to remove while the motor is running. Also after removing the oil fill cap the idle will drop and the motor will almost die if the AOS is bad (make sure the motor is warm when you run the test)... If the idle goes up the AOS is probably good.

Edited August 24, 2011 by Jager

[andrewamberleigh]

Well, my replacement AOS is faulty!!! its a shame. I am looking at the design and thinking about makeing a replacement from scratch. I think I can pull it off. We will see.

[Jager]

Well, my replacement AOS is faulty!!! its a shame. I am looking at the design and thinking about makeing a replacement from scratch. I think I can pull it off. We will see.

What is your oil level... Is it well above the full mark?

[logray]

These might be interesting reading for you...

http://forums.pelicanparts.com/porsche-996-997-forum/571188-i-eliminated-my-aos.html

http://www.pelicanparts.com/techarticles/Boxster_Tech/09-ENGINE-Air_Oil_Separator/09-ENGINE-Air_Oil_Separator.htm

[andrewamberleigh]

like the first post, I have also been an engineer for a long time. I am currently an engineer for eaton. I am looking at a couple different styles of check valves and the combination of baffles internal to the current aos frame. I am also considering a couple inline aos that are available in the after market. I understand the theory behind the aos and have had cars that I had to design kiys for. I have even looked at pressure activated pumps (i used a pump on my mustang to releive crankcase pressure). I have also wondered what the simple addition of a couple screens would do. I have alot of ideas and much of the equipment to bring them to life.

Sorry if my post is a little broken up, I generally reply from my phone.

[logray]

Since you have a Boxster I would go with the larger Motorsports version.

[Jager]

Well, my replacement AOS is faulty!!! its a shame. I am looking at the design and thinking about makeing a replacement from scratch. I think I can pull it off. We will see.

What is your oil level... Is it well above the full mark?

Have you had a chance to check your oil level? I wonder too much oil in the motor causes AOS failure??

[RFM]

The oil level should always be at the right level, before starting examination concerns excessive oil consumption/smoke. I would do that first, then do a test drive, the exhaust should be very hot since he is completely contaminated inside with oil residues, and take a look if the smoke is reduced. A bad new AOS is rather exceptional, the cause of the problem may be elsewhere.

[andrewamberleigh]

The oil level is in the middle. I checked my new j-tube that I replaced at the time of the aos swap, and it was full of oil. The aos diaphram is also completely coated in oil. What else would cause the failure? Excess crank case pressure? The car has absolutely no leaks, I would assume excess crankcase pressure woild cause rms failure, and other leaks elsewhere.

[andrewamberleigh]

The car never overheats, has no oil in the coolant or visa versa, does not consume any coolant, has no check engine lights, and idles relatively smooth. There have been no metal particles in the oil. Never been in an accident, has good compression accross the board. Car really runs awesome.

[logray]

Check this out, I don't know if you installed the replacement replacement unit yet, but this might help diagnose your CCV.

I think you have to contribute here to see it though (well worth the money).

[andrewamberleigh]

Can you give me the jist?

[andrewamberleigh]

Ok, I can make that in no time. I will attempt, but I think that I will try the new aos first.