1800 miles into my trip, overnight white smoke at start-up

Hey gang, I'm currently 1800 miles into an insane @foodbiker road trip of a lifetime, from Boston to South FL and back in Cherry, the 262K mile Boxster 2.9L. Likely saving that for another post when time allows. Should be well north of 3K miles when I get home. I'm running into a potentially minor issue on the road, and feel like I'm supposed to be one of those guys who should "know the answer." Well, I figure it can't hurt to simply double-check, especially as I'm so far from home. We all know that a little white smoke upon start-up is a feature and not a bug. For years, I've had some when I've left the car to sit for a few days and it goes away pretty quickly -- so I've been unconcerned. But before I left, I did an oil change of Driven DT-40 (5W-40) and the car has run exceptionally smoothly so far. However, I've noticed that the white smoke happens now less than 24 hours since the last drive overnight. I don't think it happens if I make a quick stop or the like and the car is warmed up. Especially given that this is happening in southern and warmer client's it doesn't seem to be a cold weather thing. I'm trying not to stress out about it, but let me know your thoughts but I have another 1800 miles to go before I get home in about two weeks. If there's a major question about it all, I'll just ship the car home. Possible thoughts after a Google search (in italics) Normal condensation : A small amount of white vapor that disappears quickly after starting the engine is often normal, especially on cold days, and is simply water vapor from condensation in the exhaust system. Well, it definitely never seemed like water and it always smelled foul like burnt oil smoke. But it goes away if I regularly drive the car, so I didn't stress about it. But now that it's happening overnight no matter what I do, I'm beginning to wonder. Blown head gasket : Thick, persistent white smoke that smells sweet is often a sign of a blown head gasket, which allows coolant to leak into the combustion chamber. This is a serious issue that can cause overheating and other severe engine damage. Nope. Smells like burnt oil or the like and it goes away. But the initial smoke is indeed thick. Engine temps have remained consistent at 175ºF (the gauge that lies - it's not exact). Faulty Air-Oil Separator (AOS) : A common problem in Boxsters is a failing AOS. This part can fail, causing oil to be drawn into the intake manifold and burned. Symptoms: Look for persistent white smoke, especially on startup. You might also notice that the oil filler cap is hard to remove due to excessive crankcase suction. What to do: A faulty AOS should be replaced. You can also check the throttle body for a heavy oil film, which indicates a bad AOS. I'll likely replace the AOS over the winter prophylactically, but it's not persistent. Apparently our AOS fail in a major way -- with white smoke all the time, so I doubt it's the culprit. Overfilled oil : If the engine oil has been overfilled, it can also cause white smoke. Check your oil level and drain any excess if needed. Nope. I made a perfect fill with 8 quarts and it was still the same oil level back in NC. Cracked intake manifold : In some cases, a leaking intake manifold gasket can allow coolant to enter the cylinders, resulting in white smoke. This is especially true for certain Boxster models. This is the final culprit, but it just doesn't feel right as a solution. **** ​ Anyhow, the car seems to be running just fine but clearly the longer the 2.9L sits, the more smoke it generates upon startup. As I've never racked up this kind of mileage on the car before, I don't want to destroy it on the way home. This may be nothing, but better ask twice and drive once. Thanks for your help, everyone. Cheers.

Maybe not temperature-related as you say, but what's the humidity doing in the course of the trip? Dew point at night? I wouldn't be too worried.

What’s your mileage? Do you see any evidence of oil consumption on the lame oil meter? When you open the coolant fill do you see any evidence of foamy milkshake? Lastly, how much smoke are you seeing? I had an AOS go completely bad on my 986 and I can report to you that it looked like one of those mosquito fogging trucks that they used to use at club med. Unless it’s like that? I’d keep rolling and make sure that it has the fluids right and tight. If something egregious is going on riding further toward home isn’t gonna make much of a difference in the final outcome. PS A failing AOS might present itself in more than one way.

Knowing @foodbiker - OCD much? I understand the worry.. you've seen a change in behavior.. but, it's a change that probably (tech-term, meaning don't blame me if I'm wrong) is attributable to the change in temps. You're in southern Florida. Temps at night? How do they compare to the temps at night in Boston? You're using a different oil then you have in the past. Does the oil level appear to have changed much? 1,800 miles - have you had to add any oil? If no, soldier on. My WAG - Cherry isn't used to this much attention, but she loves it, so that's the only way she knows to tell you that she loves it. And actually, I suspect the higher average temperature is what's causing the smoke on startup. Porsche allows some silly consumption, like a quart of oil in 800 miles is "normal". I consider a quart of oil in 1,000 miles as my personal cutoff for excessive oil use. I had (I told you that story) a VW Scirocco that used a quart of oil in 50 miles once—that had an issue. If it changes on your way back - and becomes bad enough to consider shipping it north, you have an advantage in it being a shorter shipping trip, so probably cheaper. They usually figure by the mile. If you want to be super cautious - take the Autotrain from Orlando north to Virginia, then 81 north from there.. cuts the return trip down to 1/3rd what it would have been and you'll have a nice story about the overnight train ride for your blog.

My guess is the AOS . If it's only puffing a bit on start up and not constant, and the temps are remaining consistent, then the chances of an oil coolant mixture is close to zero.

putting the best face on it? Nobody will be tailgating you on the way home.

Do you garage the car when home? If so, the difference could seem dramatic when it’s not garages due to humidity and/or temp differences as some folks have said. I would definitely keep driving it. It doesn’t seem like a big issue. Might not be an issue at all. Enjoy your trip. Sounds like a fun one.

For the smell you mention, are you sure that isn’t just cold start enrichment? I also get the steam cloud startup white smoke on damper days (short exhaust system heats things up quickly), and I can see how someone trying to diagnose the dreaded smoke on startup jumping back there to smell it on startup getting that rich fuel whiff getting a little concerned.

It's normal, I notice it most when parked on an incline.

Thanks for all the replies, everyone. (Thanks for the wisecrack, @deilenberger ...) Again, it's probably nothing as it always did this since I got the car -- but it's just much more pronounced now that I'm on the road and driving so much. Figured I'd simply double check before proceeding, especially while I'm currently in safe harbor in South FL visiting my folks in the middle of this incredible trip. To answer a few questions: Humidity / Temperature - Likely unrelated. In fact, pre-trip in September, it was stored for a few weeks indoors, alongside with my friend's temperature controlled car collection. Ridiculous amount of smoke after letting it sit for a few weeks. It always smells bad -- not like damp moisture that comes out of an exhaust or rich fuel -- I'm squarely guessing burnt motor oil. Definitely more of a smoke bomb that comes out - LOL. No major differences whether the car is sitting outside or not. Same exact smell, despite the change from Mobil 1 OW-40 to Driven DT-40 5W-40. Parked on a level surface all week, and I generally didn't push the car past 80 mph. Lots of cruise control in the 70s. 2.9L's mileage surpassed 262K on the trip. Oil check - I'll have to warm up the car first, and will check the oil consumption after 1800 miles tomorrow. I checked oil when I reached Durham, NC -- about 800 miles out, and there was zero consumption. I have a spare quart that I packed for the trip; it was two bars on the oil meter when I left and in Durham. A third bar would have been at the full mark, if memory serves me well. 8 quarts exactly. No foamy milkshake (I doubt it's that either). Major smoke cloud - think James Bond LOL smoke screen. (okay, maybe not that bad but not great either). Again, I think I'm going to run with it and see how things go - the trip resumes again in just under a week when I start heading back north. My guess is what's happening is that oil is seeping somewhere overnight (AOS slowly failing? Engine seals?) and is being immediately burned and blown out. Another possibility is that it's just the normal amount that happens to every Boxster after sitting, but it's just that the amount of smoke is significantly more than what's normal (ridiculously more than my former 987.1S) -- meaning that there's far more oil getting in there to burn. The question is why. Thanks for all the input and stay tuned.

As a WAG, 262k - those oil control rings don't owe you anything... they've done millions of miles up and down those cylinder walls.. Could just be the engine is getting to where it might need a freshening up. The long trip could have cleared out some crud (tech-term) that might have been helping the rings seal. It might go right back to your normal morning smoke once you're back in Boston. The oil level is of interest..

This may have been said but white smoke is more moisture or coolant. If you were burning oil the smoke would have a blue tint. It might be subtle but I have seen it plenty of times on the highway. And the smells are different. I think it’s just temp/moisture but worth a look over when you get home. On my 04 Subaru WRX in the winter that first start up after a week used to scare me, holy smokescreen. After 22 years and many miles I realize it’s normal. Have a good trip.

@deilenberger - That was my other fear = rings = expensive proposition. However, from that I'd be thinking smoke-all-the-time kind of thing. Kind of like the regular 3rd cylinder on my former (and most classic) VW bugs. In this case, that's not the case - and I remember what that looked like when I'd step on the gas pedal. Regardless, I do think any "crud" blow-out will be ideal and this trip is hopefully great for the car. Will be interesting as Cherry has sat for a few days and I'll be starting her later this AM, and taking a short trip -- ideally far enough to warm up enough for the oil meter. Each block on the gauge is 400ml, so one would expect that after 1800 miles that the light would have come on by now. After the last oil change and post-valve cover replacement, I think it was only an 800mml loss total after 5K miles. Stay tuned on that. Also curious as it is ridiculously humid here too this AM -- unlike most up north. That's South FL for ya... @Ernest72 - Thanks for the good reassurance. I'll have to get a second pair of eyes on the smoke color, especially as I'm not the best with that. Wondering if it's a white/blue mix, TBH -- which would confuse matters. Wondering if what I'm seeing is something like 80% overnight/sitting moisture and 20% oil. Again, I'm sure it's fine but figure it never hurts to check. Definitely a good morning to check my fluids as I left with everything on full. Thanks, everyone.

I am impressed that you would take such a long journey in a vehicle with 262 on the clock, good on you. If it needs a rebuild? Maybe shop around for a little bigger powerplant and just swap it

Reading lots of input here on the white smoke, which can certainly be caused by numerous issues. Although, if I had to bet the house, my past research into this would lead me to suspect the air/oil separator. Saw some mentions about temps being a possibility, but living in southern Florida I can attest that the past week or two the temps have been very moderate, with highs in the upper 70’s to low 80’s during the day, and nights in the upper 60’s to low 70’s. Definitely not any extremes that would lead me to believe it is temperature related. foodbiker : not sure where in Florida you are located, but if I can be of any assistance I have a decently equipped garage, QuickJacks and most necessary tools. Also, know of some good indie shops in the surrounding area. And if you are anywhere near me, St. Lucie County, would love to see your ride, grab a cold beer or a hot coffee.

Same offer if it goes near the Atl, there’s even a foreign auto parts store near me.

You guys rock as you always do. Thanks. First up... If I can indeed meet up with P9 peeps on my trip north,that would be great fun -- which is part of this Food Biker / Knife and Steel adventure to be sure. @deilenberger is surely already sick of me from my visit during my first stop on this trip. @WTFChuck - Way cool and thanks for the wrenching safe harbor offer -- QJ are amazing for such. If the schedule/timing works out, I'd certainly be up for a fun and early quick pit-stop on the way north. Feel free to send me a PM with details; it would likely be Wed/Thu AM on my way out of town. Instead of a cold beer or hot coffee, it would like be a cold coffee given it's FL! -- especially it'll be many more miles before I sleep that day so no beer -- LOL. I-95 is boring and every second of milled asphalt is proving to be loud and not fun. @Boristhespyder - Same here. (For whatever reason, I thought you were out west!) Unclear if I'll be swinging through ATL, but will keep you posted if I do. If so, it would likely be a few days afterwards -- as I may drive west from Charleston. There's a non-zero chance I'm going to brave the traffic and head to the dealership where the original owner got the car and see if they'll get me the redacted service records. It would be great fun to meet you in person after all this time, Tony. Thanks for the encouragement RE: the high mileage. My feeling remains that the car can take it, and one reason why I'm doing all this is to ideally prove that our P-cars needn't be expensive, nor garage queens. Agreed about the temps and humidity - super moderate on this southern leg of the trip. Well, here's the update from yesterday. Don't laugh! ZERO smoke yesterday at start-up after sitting for maybe 2 days. NONE . If had started the car, it was to move it briefly between two driveway spots to remove the hard top for FL driving. This has never happened before. It was like I had been out driving and was making a pit stop and was a nothingburger. I don't recall that ever happening. Car seems to get reach the fake 175ºF much faster down here in the warmer weather, but maybe that's just me. Cherry seems quite happy down here. Hoping to finally take my pop out in the car with the top down once the cold snap sets in early this week. After 1800 miles, there's been ZERO oil loss via the oil meter. NONE. Again, there are three boxes (400ml each) and I had filled up 8 quarts exactly -- which I had intentionally filled up to the lower two boxes. Couldn't believe it. I'm likely taking the car out tomorrow again, as it will have likely sat for 48 hours in the same spot and will report back. My first guess is that the AOS may be tired, and I had intended to replace prophylactically when I first bought the car a few years ago. I doubt it's a catastrophic AOS failure, as that would have been smoke bomb city all the time when they do fail. No idea if it has ever been replaced in my 987.2. Again, most of the time it's a HUGE blast of smoke that's like a mosquito truck if the car has been sitting -- but that goes away once you drive away. Can't hurt to replace it during a wintertime wrenching project and see if it improves things. Doing an engine refresh would unfortunately be financially catastrophic for my non-existent budget. I originally looked in to pricing/labor a few years back -- when I had an oil leak from the driver's side valve cover -- and I got away with just putting everything back together via a partial and one-sided engine drop for that. Plus, my first Blackstone analysis 5K miles ago passed with flying colors per engine wear -- so I'd likely live with it for now. Again, it was more of a "is this normal?" question, especially given that I'm indeed so far from home and the recent smoke blast seemed far more severe than I recall. Anyhow, that's the scoop this morning. Again, if any of you are reading this on the east coast and want to meet up, feel free to PM me as I may be passing by/through. Obviously no promises, given my route/timing is in major flux. Years ago, I did so on my motorcycle with BMW forum members and it was great fun. In a few days, I'm likely headed to Charleston, possibly making a quick detour to Atlanta, headed to Deal's Gap for the Dragon for the first time, headed to the BMW plant in northwest SC, doing some Blue Ridge Parkway driving, driving up through PA to avoid DC/Philly traffic, and then back home to Boston in time for Thanksgiving. My trip south largely hugged the coast short of Durham, SC and has been an exceptional trip so far. Oh, one other interesting thing. Given some annoying window squeaking on the hard top weatherstrip, I finally bit the bullet -- shelled out ~$40, and ordered a tube of Krysol overnight. Apparently this is the stuff that the dealers use to stop squeaks for convertible tops, sunroofs, etc. -- similar to Gummi Pfledge (which I already have back home in Boston). It's PFAS based (yes, I'll definitely be using gloves as it's a forever chemical), but fingers crossed it'll make the drive north a bit quieter. I thought about doing this a long time ago, but repetitive noise after 1800 miles can and will get to you. Cheers, y'all! - Food Biker (Seth)

Hey Seth, in the meantime? If it’s using any oil, and it goes down to a lower level on the bar scale, leave it there in the good zone. This is just speculation on my part, but I believe lower acceptable oil level should reduce smoke and take a load off the AOS .

Oh, I agree @Boristhespyder - If it drops another 400 mL, I would just leave it alone at one box. 400 ML is likely not much to make of a difference given the massive 8 quart capacity, but I’m certainly not going to be asking for any trouble or change of variables while I’m on the road unless I absolutely have to. Once I get to the AOS, I am curious to see how dirty the intake manifold and related hoses are.

So, another night of sitting out in South FL. No smoke. None. Stay tuned as I head north later this week, and the temps drop. The plot thickens.

We had a little snow today in the mountains of Western NC. No real accumulation but ATM it is below freezing (23F) here. Glad I got all my outdoor winterizing stuff done last weekend when it was 70F.

Unlike the smoke…

Oh, wow - @RSchwerer - Especially if I'm headed in your direction, I sure hope it warms up! I'm still running my summer tires... Quick car start to move it today. No smoke again. Will be watching as I head north and the temps drop...

@foodbiker it's supposed to warm up here by the weekend with highs around 70 and nightly lows around 40. Of course AccuWeather has been wrong before.

I only get the white puff on start up when I have my 2.9 on a slope with the engine downhill. Check your position, try to make sure you keep the nose on the downhill. Yes even a small incline makes a difference on mine. I have never got 8 quarts into mine after a drain and filter change. It reads full at 7. Enjoy the trip, Ive done 2) 2k trips in the last 2 years and had a ball.

I get the same thing as Terrepin Station above. And it always happens after a very short run time - backing the car out onto the (sloped) driveway, washing it, then pulling back into the garage. Next time I start it, a big smoke cloud, but only lasting a couple of seconds.

Hope everyone had a fantastic Thanksgiving. I made it safely home after 4250 miles and a few days to spare before Thanksgiving; more details to follow -- including a second CEL blown 4200 miles into the trip -- surely having to do with accidentally overfilling the tank. Recovering from a bad cold here, will be checking the codes when I feel better. After parking in all sorts of positions overnight for nearly a month, I think (?) it seems to be a rear tipped down or even level situation that causes the smoke cloud. If it's parked nose slanted nose down, as @Terrapin Station says, I might generally escape it. Will have to do more specific testing to be sure. It's just the significant volume of smoke generated that has me uneasy. Stay tuned.

what i said...