[video] Smoking 996 -- fingers crossed for oil separator

Please tell me a broken AOS could explain this cloud of smoke! http://vimeo.com/9986373 It looks white enough to be coolant, but smells like oil. Coolant and oil levels are fine. No milkshake. Heard a bit of squealing as I was driving the last mile or so home -- no CEL or other bad behavior from the car. The following morning on start-up, huge plume of smoke. This video is the second start, a few hours later. No plans to start it again until it's at the shop. So: AOS? Or am I engine shopping?

How many miles do you have on your 2000 model year Carrera? Assume you to be the second owner. Any records from #1?

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Nice cloud of oil smoke. You're not engine shopping just yet. AOS would be my guess. Engine would have to be pretty sick to allow that much oil past something mechanical and I think you'd know something more serious wrong by way engine ran (if it ran at all) and sounded and acted. Do not start engine again. Get flat bed tow truck and be sure you stress engine can not be started, car is a non-runner. Tow truck operator might try to start and run engine anyhow.... they're all lazy and care nothing for preserving a car's engine so watch for that. You might consider safely disconnecting the battery or the engine start fuse just to be safe. Get car to dealer service department. Call ahead and let service manager know you suspect AOS and insist engine not be run until a proper diagnosis made. Service departments a bit more reliable and chances are high car will pushed into service bay once car dropped off by tow truck operator. My 02 Boxster is on its 3rd AOS. First one failed at around 80K miles, 2nd one failed at maybe 180K miles and engine now has over 229K miles on it. I may have the current AOS replaced this summer just as a preventative measure. The AOS can fail and be replaced and the engine no worse for the experience if you're aware of the dangers of continuing to run the engine when AOS (or something more serious) suspected. Sincerely, Macster.

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98k. No records of substance from previous owner, but last 40k were all mine -- saw it through the 90k service a bit ago. Garage always gives it two thumbs up.

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Thanks for sharing your experience. I will be personally escorting it onto the flatbed tomorrow AM. The shop is just a few miles away, so I will be escorting it off the truck as well. I'll certainly post an update as soon as I have one.

With earned respect to Macster above, if there are no noises coming from the motor I would start it again and let it idle for a minute. Assuming the smoke dissapates (burns off), rev it up a bit and drive it around to clear out the oil residue that infiltrated your motor via the AOS. If the smoke continues, or there's any unnatural noises then shut it off and follow Macster's advise above. If not you can keep driving it, but try letting it idle for a minute before you shut if off each time. They're only catastrophic when they completely fail and fill your cylinders with oil residue. It happened to my 3.4 at Laguna last August filling the garage with smoke. I let it idle then continued to race it all weekend letting it idle before shutting it off. It didn't smoke again all weekend though I changed it when we got home.... So yes, you need a new AOS and the sooner the better. There was a thread a few months back about costs to replace one. The spread from dealer to independent was all over the place. The part is only $110. or so, but the labor and how best to undertake the task vary. Call around and get 'firm' quotes preferably from someone who's actually done it before.... PS: Welcome to Rennlist....

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How'd you do that Dan?

WOW, 007 smoke screen. I have some questions: What does the AOS do and how does it work and whats it reason for being and what damage can come of running it like this?

A coolant leak into the cylinder will generally affect only one bank, so steam or white exhaust cloud will only be present out one side of the exhaust, not both. Yours seems to smoke equally out both, so more than likely AOS. This can oil foul your spark plugs, damage your cats and possibly your O2 sensors, and cause a CEL. That's why you shouldn't drive it. DIY if qualifyed or have it flatbedded.

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Thanks for the advice and the welcome. Years of lurking, just a few hours of posting. Hopefully I'll be able to give back with a well-documented account of this event. The AOS is also know as the "aerial occlusion system". The civilian models of the 996 must have a properly functioning AOS inhibitor -- otherwise they would be considered a mobile weapons system and barred from import. Here's a shot of the standard military 911 (the base platform from which all our cars are derived), before it's detuned and inhibited down to the civilian model:

I had a 996 smoke at start up every once in a great while after pulling in from a hotlap, and seen this happen on others also. AOS seems to be common and I've seen 2 other cars that needed them, I've yet to have one break on one of my cars however. BTW, from personal experience/contact with a few dozen people, RMS and AOS are the most "serious" engine issues I've come across. AOS would also cause what you're seeing (and worse). How did this start? How long has the car idled with this issue so far? If the answer is that you came back to start the car without any previous symptoms, and it's just smoked like this a very short time -without accompanying knocks or the like, I would second the suggestion to start it and let it idle for a minute to see if it will clear up on it's own.

Pull of the airbox and the e-gas throttle body and look for oil in the plenum. When my AOS went bad there was thick oil in the plenum. This was the source of the oil getting into the cylinders and causing all the smoke. This way you can check the engine without starting it again.

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No early symptoms; after exiting the highway, ~1mi from home, I noticed a squeal which was present at idle but disappeared after 2-3k RPM or so. The oil light flashed briefly (just for a second) as I was turning onto my street, but the level & pressure looked within expected ranges at the time. I smelled something amiss upon exiting the car, but didn't re-start until the following morning. I certainly hadn't been driving hard. As soon as I detected the plume I powered down, so it hasn't idled for any appreciable time. Given the relatively low cost of a few hours of attention from the shop (compared to a new engine), I'll probably wait to fire it up again until it's in their hands.

AOS...is similiar to the pancake valve on the audi....like a breather for the engine once it develops a leak the air and oil arent seperated anymore and the engine intakes oil. The pancake and engine bretaher lines on an Audi can be replaced in about 45min unlike the multiple hour process these engines take due to lack of space. I had an oil/air seperation issue on my big turbo A4 avant...and it looked very similiar to this mess, once the vacuum lines and pancake valve was replaced it was fixed. Looks and sounds like an AOS Failure, I wouldnt sweat it, doesnt appear to be anything catstrophic, It looks worse than it is. If you heard metal bouncing around and crunching coming form the engine Id be worried. Basically the AOS prevents the engine from breathing directly into the intake manifold and burning oil and massive amounts of oil vapor.

Yes, in that case sounds like an AOS. Keep us updated.

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I would have to disagree with your advice. While running the engine may prove to be harmless there is a risk and I would not advise anyone to accep this risk cause catastrophic engine failure is possible. The risk is too great for the possibly benefit. As Jake Raby points out and it is very good advice when the engine makes noises and I'll add when it smokes heavily, avoid running engine at all and get it to qualified shop for diagnosis and repair. In most cases no good comes of trying to run the engine. The 1st time my car's AOS failed service manager advised me to avoid driving the car. I was around 40 miles from dealer and seeking to avoid spending any money I didn't have to -- I was out of work. Cost me I forget how much to have car flat bedded and to make matters worse I had to start car and back it out of garage and through snow drifts -- got it stuck! -- on to street to position it so flat bed operator could get car on truck. I was quite concerned engine would blow at any time, especially as I was rocking car back and forth to get it unstuck. At the same time as my car was acting up another same color car owned by another person started acting up. When I talked to my service manager he told me he gave same advice to this other owner and he insisted on driving the car. Engine suffered hydraulic lock and I believe engine was ruined. I believe this car was under warranty still. Mine was not obviously having nearly 80K miles on it. Attached is pic of my car smoking with bad AOS. This the 2nd one. This time car was as it turned out 90 miles away from dealer (same dealer that fixed 1st AOS). $150 tow bill later car at dealer's for repair. Sincerely, Macster.

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Plate number tells us a lot. http://www.bar.ca.gov/pubwebquery/Ve...PubTstQry.aspx Once you do a look up I can see model year. I also noticed that the car started out its life in a different area from where it is now--a good indication of an ownership turnover.

Looks like AOS failure. I would not drive or start the car. You can damage the cats, O2 sensors or worse. Yes, you can hydro lock the engine if the oil in the intake runs down the intake runner.

Update from the always-wonderful Carrera Motors : Definitely AOS failure, ~6 hours to replace, ~$840 total parts+labor. Dropped off the car at 10A, it's ready to pick up now. I'll scan & post the invoice once I have it. Suggestions for what I should do with the other $13k I didn't have to spend on a new motor?

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Good for you. Looks like you did okay on the cost to repair as well.

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Bank the money, just in case! Seriously, I had $15K set aside for the last 5 years or so. Finally put it towards a new 2008 Cayman S then a used 03 Turbo. So far haven't need the money and the car and on its original engine (and clutch) rolled over 229K miles a few weeks ago. Driver's side floor mat worn out though. Crap German floor mats! Sincerely, Macster.

Glad to hear it was a "minor" Repair!!!

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My car does that now upon initial startup for 10 seconds, blue smoke but goes away when driving. Actually it only does it when its cold out. +15degree C and it doesn't. Just wondering if you had the smoke and it went away, after driving. I have brought it to a really good independent, actually 2 of them. One thought they knew what it was before they looked at it and then were dumb founded as to the cause. I figured they did the AOS check where you take off the oil cap and cuase the engine to stall out from suction but my car runs fine without one. Then again the 996 GT3 forum, its quite normal for blue smoke startups.

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Good one, Mac!

I'm glad it was only the AOS. I had a similar thing happen to me on Sunday with my '03 C4s, but I suspect is maybe worse and have a cracked cylinder liner. A hugh plume of white smoke came out of only one exhaust and the check engine light came on. I promptly shut it down and had it flatbedded over to the repair shop. I'm keeping my fingers crossed. BTW, the cost of a remanufactured 996 3.6L engine is almost $19k now with a core charge of $3k, a total of $22k just for the engine. Add in labor and taxes and you are looking at $24-25k. Needless to say I won't go that route should I need a new engine. Anyone know of any good salvage engine dealers?

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Yikes, $25k!!!

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few people here looking for a blown engine donor.... but, Im sure your motor can be rebuilt if its a cracked head...

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you numbers are too high

Two dealers gave me the same numbers, if you know where I can get it cheaper, please let me know.

I found another dealer that will do it for $21,500.

Suncoast is still selling re-man's for $15-$16K - this was December 22 2010 pricing.

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you could send it to me who is still in need of a new motor!

I'll give them a call. thx

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Auto Strasse in Costa Mesa, Ca. has rebuilt a majority of the so cal spec box motors along with 2 for my 996 race car and several other 996 cars I know of. It's relatively easy to ship a motor in the Cont. US. 1 year warranty IIRC..... Ask for Robert the owner.... [phone removed]

My mechanic has mine at a rebuild shop he trusts in CA. He told me total rebuild if they can use your core is about 15K to 16K with all updates and a 1 year warranty. I did a bunch of research and found some prices around 21K for the same thing. Also I found a lot lower cost rebuilds with a much shorter warranty. I believe there is a ton of junk some unscrupulous people are trying to get rid of and will sell it to who ever will buy it. I think if you are like me and do not have a lot of experience you are better off letting this to a pro you trust to figure out for you. I am hoping to get mine back in a few weeks. Once I do I will do a full write up for the list.

Confirmed the it is a cracked cylinder liner and not the the AOS. I just spoke with Suncoast and they want $14,500 plus the core charge of $3,300 for a remanufactured engine from Porsche. I'm having them check to see what the chances are of Porsche rejecting the core. Anyone have experience with this situation? Depending on what my shop can find in a salvaged engine I may go this route.

Can someone explain us to these problem by basic english. Please not hard language. Firstly yes sometimes my car is making these type of white smoke when i was startup. this smoke smell like insecticide. ( this can kill the insects. ) I dont understand these long thread. What is it smokes source ? My engine is broke down or something ? What do you think please explain me

If it is a sweet smell with the white smoke then it is most likely anti-freeze. Could be the AOS just starting to go. A tiny bit of smoke on startup is normal.

In case you haven't already I'd check out Flat 6 Innovations. For about the same you can send your engine in and get back a much improved reliable rebuild. Your local indy can R+R it for you.

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Good one. I need some documentation on that so I can take my 996 on a deployment. Will the documents need translation?

Has anyone bought a rebuilt engine from LA Porsche or dealt with them before?