Blueish smoke when driving AOS? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

suburban99 · 03-12-2022, 08:16 PM

Just about got this car back on the road. Been off the road since 2013.
In a nutshell
No smoke on startup
Idles good.
No CEL
Drives very good
Doesnt seem to lack power.

Smokes under load. I mean alot of smoke. Had to pull over to put the paper bag over my head so my neighbors didn't recognize me...turn off car for a minute or 2 and restart...no smoke.

I am thinking the AOS is shot and allowing oil into the intake. Car runs too good for it to be a major issue, and does not smoke on startup...oil fill cap has alot of suction..

JFP in PA · 03-13-2022, 09:25 AM

Aos...............

safesaxbdd · 03-15-2022, 10:55 AM

Def seems like AOS could be culprit, though mine only smoked a **************** ton when it had already failed. Prior to failure it just would smoke a bit on startup.

john12312 · 03-17-2022, 10:26 AM

AOS. Mine smoked like a MOFO when it happened. Good news is it shouldn't be difficult to replace it yourself.

suburban99 · 03-21-2022, 07:51 AM

Changed AOS on the weekend. Stretched the J tube to make it fit using a heat gun. Will order new J tube.
Car runs good, drove it for about 20 mins. Got on the throttle a little and had a small amount of smoke. I am considering pulling the intake to clean it. If I don't pull it how long does it usually take for the residue to get burnt off?

A side note. When installing the stock hose clamp on the bellows..if you squeeze the lower bellows clamp all the way open you can tie it with mechanics wire. Then slip the unit over the port on the engine tighten bolts and snip the wire with your sidecutter to release the clamp.

FoFoJoe · 03-23-2022, 07:56 AM

My AOS went out within a couple months of buying the car, what a gut punch that was seeing the dash lights go spunky while I smoked like a high school bathroom.

Careful on that small tube that connects to the top of the AOS. I cracked mine when we swapped it. Easy to buy a replacement if that happens though.

suburban99 · 05-18-2022, 08:15 AM

Replaced AOS with a cheaper off brand version...
Car is better, but still smokes a small amount when I get on it.
Removed intake no oil in intake, but small amount of oil in J-tube. (there was oil in intake before I changed the AOS to the new one)

Apparently I am not the only one that has this problem with this particular part.
Also think the lower AOS hose (plastic) is leaking. I guess i need to order the Porsche AOS and the J-tube and the lower hose..?

dghii · 05-18-2022, 05:18 PM

+1 Need OEM AOS. This job is enough of a PIA to try to save a few $ on aftermarket. Same for coolant tank....

Rob175 · 05-19-2022, 05:46 AM

Define "AOS" please for some of us who don't wrench. thx

JFP in PA · 05-19-2022, 06:42 AM

Air Oil Separator

suburban99 · 05-25-2022, 11:50 AM

Porsche AOS installed including new J-tube and the lower AOS hose plastic tube piece..
A real PIA to change the lower hose/tube. It is Threaded thru the legs of the intake manifold...Airbox/ intake manifolds/throttle body etc all needed to be removed.
AOS is not to bad to change.
So far good! No smoke at all. Hopefully that's the ticket! Thanks for all the input.

JFP in PA · 05-25-2022, 12:56 PM

Quote:

Originally Posted by suburban99

Porsche AOS installed including new J-tube and the lower AOS hose plastic tube piece..
A real PIA to change the lower hose/tube. It is Threaded thru the legs of the intake manifold...Airbox/ intake manifolds/throttle body etc all needed to be removed.
AOS is not to bad to change.
So far good! No smoke at all. Hopefully that's the ticket! Thanks for all the input.

Next oil change, lower your oil level two bars below the full mark (around 1/2L), which will help even more.