996 AOS again?

Last month I decided to treat myself with a little early 19th birthday present. I sold my 2004 Mercedes SL which I had for about two years that was in perfect shape and had no issues with to get a 2002 Porsche 911 Cab with 62k miles. It had the ims done with the updated and bought it from a dealer in Dallas who had a Ferrari 458, Bentleys, all that good stuff. I drove back to KC where I live and RIGHT when I get back 5 mins away from my house at 2 am it looked like everything was on fire. I didn't know what the Air-Oil separator was at the time but it went out and the next two days I got the genuine Porsche AOS and put it in. It's been a month, maybe a month and a half and I haven't seen ANY smoke at all since until yesterday. It smoked a ton on start up and then a minute later it was all clear again. I drove to dinner and after it smoked a little again. It also smoked this morning after sitting in the garage over night but not as bad as it did the first time yesterday. I know when my AOS was replaced a month ago it did smoke on start up for the first 2 days to get all the residual oil out. My question is could my AOS go bad in a month and a half again? Or could it just have dumped some oil into somewhere and it's kinda a once in a while thing? Yesterday I did drive it hard for a minute hitting 120 on the freeway. By the way there is no sign of oil in coolant.

I had an OEM AOS fail almost immediately out of the box if that helps

When it failed was it smoking horribly or just on start up? The job took me about two days to do and do not want to do it again.

I know you don't want to do it again! It is such a PITA job..been there, done that. However, if you read the many AOS threads on here you will find - replaced and has worked great for years, replaced and it failed again in XX months/miles, replaced and it failed out of the box. If you are smoking out the tailpipes, it has failed, or is about to fail again sorry to say. That said, it is a critical component and can wreak havoc on your engine, flooding it with oil or hydro-locking the engine with coolant. Best to get it replaced again. There is a way to test for a failing AOS with a manometer and modified oil cap. Look it up because you might want to do that first. https://rennlist.com/forums/996-foru...-question.html

I will see what it does today and tomorrow. Runs and drives great. My last AOS failure had 0 signs of failure saw no smoke at all at the dealership or the 7+ times I started it up at gas stations, restaurants, etc. on the way home it happened just driving completely normal and all the sudden BAM blue/grey smoke covered everything in view behind me. I know these cars do smoke on occasion and I am just hoping for just a weird kinda random scenario. Does anyone know what causes these to fail? The 911 is the best daily driver sports car to own imo (so I thought) so far I have done the AOS, strut bearing started making creaking noise so did that, occasional sticking lifter noise, and convertible top cylinders started leaking so now digging into that. Its only been a month and has not been the best to me.

When you replaced the AOS, did you check the inside of the two intake manifolds? They could hold like 1/2 quart of oil there. Any residual oil there could got sucked into the cylinders when you drive aggressively despite a new AOS. The manometer test is still the only reliable test to verify the AOS, regardless of its age.

Do the manometer test. They're cheap. I got one on Amazon for like 35 bucks. Nice tool to have in your toolbox too! I thought I would need to replace mine until I did the test and it tested fine. My car is actually running beautifully right now and since I posted a thread about this issue, I haven't had any smoke on start up. I even parked at the nose down incline at my golf club yesterday to test it and no smoke yesterday! These cars are expensive to own. I've done so much maintenance to my car since I got it in Jan 2017. Just to name a few of the things that don't include the basic maintenance: Water pump went bad so changed that and the thermostat and of course changed out all the coolant while at it and also changed the drive belt. Coolant tank started leaking so changed that and the coolant cap. Alternator bearing died so put in a new alternator. The big one was remove and rebuild the tiptronic transmission. Fix an oil pan leak. I'm now dealaing with a clunking from the engine. I narrowed it down to the exhaust, right bank exhaust where I can reproduce the rattle/klank. Looks likes it coming from the cat. Don't want to deal with this and there is nothing but the annoying rattle so I'm going to leave it alone until it causes a check engine light or something. An oil comsumption. I'm at around 1/2 quart for 1000 miles. I know this isnt' a big deal, but it bugs me as my other cars don't consume a drop of oil. The car is driving amazing and I'm just going to play golf and enjoy it.

Oh, and I've got the very small leak issue from the EVAP system which is really annoying but not a big deal and I'll have to get that sorted out eventually.