Big white smoke cloud and bad smell, followed by...no issue?

Hi all, I have a 2001 Boxster S which I've had for ~3k miles of its 50k miles total (since April this year). I bought it from a Porsche dealer and it was serviced before sale. It has not given me any issues until yesterday. I started the car yesterday (it sat for over 24 hours the day before) and pretty much immediately (less than 5 seconds) upon starting there was a giant cloud of white smoke accompanied by a burning smell (which I want to say is coolant but I have no idea). The smoke was coming out the exhaust and side vents. The smoke and the smell dissapatated very quickly. I moved the car from where it was parked (on the grass) and didn't see any evidence of a leak on the ground. Moved the car to the pavement and let it sit overnight, and it did not show signs of a leak. Drove it around, no temp issues, smell or smoke. Runs completely fine, no CEL. Figured it might be AC related but AC works completely fine. I cold started the car today (~12 hours after it had last started), no smoke, no smell. No leak, coolant levels fine. I drove it 300 miles today, mostly on the highway, no issues at all. I have no idea what to think, I feel like I should be concerned, but other than the large smoke cloud and burning smell for a minute or two there has been no issues. First guess would be AOS of course but it doesn't seem consistent with any of those symptoms other than the white smoke. I wouldn't even know what to say to a mechanic about it. One of my first googles had somebody say this happened to them in their wife's boxster and then it never happened again. I have no idea what to think. For the record, I have heard / seen these cars smoke on cold start and its normal, this was 100% not that. Any input would be appreciated. Thanks.

AOS . At least have it professionally diagnosed by an indie shop, but 99% likely the AOS Sent from my SM-S911W using Tapatalk

Are you running one bar under top read on your oil level? It does sound like an AOS or a very slow leak that sits somewhere and burns off but I agree with Slingshot. Regardless, if you make sure the oil level is correct and keep said level within parameters, it will help until you get it checked.

You probably should do a "manometer" test for engine case vacuum. I forget the specs on vacuum. I think anything above 4 inches mercury is a minimum acceptable indicator of the AOS working properly. There is engine temps. and RPM ratings for this test. Also, I made a simple attachment by purchasing a new oil cap and drilling and tapping it for an 1/8-27 NPT thread to attach a barbed fitting for the manometer gage and tubing I used. If you can get a look inside the intake for oil residue, it may be a batch was just sitting there waiting to drain over the clamp band area into the intake, based on the level of the car when parked. White smoke is usually coolant and blueish white is usually oil. Even the Porsche forever coolant when burned has the unmistakable antifreeze odor. If you check YouTube videos on AOS checks, you will see exactly what I'm talking about. It is probably the same thing that will be checked by a professional. Jake Raby may also have a video on the AOS spec. when verifying health of engine for IMSolution retrofit. If you want to do it yourself and then verify by your mechanic, let me know and I'm sure we can make arrangements to purchase or borrow my set-up and gage. I have no use for it any longer. I had the same year. Check for coolant cracks in the tank, and hoses inside firewall. Get the latest generation coolant cap and replace the old one. There is an upgraded part number for it. I'll look through my stuff and see if I still have it. Good luck and let me know.

Hey @cce4life - Welcome to P9! Agree with the above...my gut says AOS. Report back and curious to see what the scoop is. Please make sure to introduce yourself in the New Members with cool photos of your 986; it's pretty much tradition around here. Cheers and wishing you many fun miles!

Here's the set up I've used to check crankcase vacuum ( AOS ).

Any link to where that can be found?

Amazon for the test instrument.. https://a.co/d/0ER7SS Model EM201B Pelican for the oil filler cap. p/n 996.107.350.52 The barb fitting from Ace hardware along with some Devcon 5 minute epoxy to strengthen the fitting to cap due to thin walled plastic.