Big oil cloud on cold start (AOS replaced)(987.1 S)

Technical question for you guys: My car recently started blowing rather large clouds of blue smoke on cold start. Its only one big puff and then nothing after. It doesn't do it every time and seems to be worse when the car is pointed downhill. I replaced the AOS (twice) which changed nothing. I would like to think it's not cylinder scoring because I borescoped the car 4 months ago and all looked clean. Also, the smoke coming from the exhaust seems equal on both sides (my Remus exhaust has fully split pipes). some more basic info about the car: 2006 Cayman S Car consumes about 1qt of oil per 2000 miles. (redline 5w-50) Consumption seems to be worse when the car spends more time at high RPM ~107,xxx Miles I have read this thread which is similar to my issue but wanted to get some fresh opinions. Currently, my thoughts are that its either bad injectors after reading this post from flat6motorsports or bad valve guides. I have not done a compression or leakdown test but I am considering it. I would like some input on how to proceed with a diagnosis. Should I go straight for new injectors? Thanks for any input!

Generally a little smoke or puff at cold start is fairly normal. Also depends on weather (condensation). It doesn’t sound like scoring. The oil you’re using is sadly also semi normal although it differs from car to car. Any soot on the rear bumper? don’t let your car idle on cold start long. I let the high idle drop and then drive. No hard excelling until full warm up… also don’t do the winter start/charge the battery .. it’s more fuel than oil into those cylinders and they don’t like that

White smoke on cold mornings is normal. It should stop when the engine warns up (condensation). If the smoke is blue, that is another issue.

Blue smoke is oil, white smoke is condensation or water… the blue puff is normal with flat 6

Dinky - what's the mileage on your '06?

107,xxx. Could have sworn I put that in the post. It is updated now as well

A few questions for you. What is a semi normal oil and why does it matter? Second, no soot on the rear bumper or at least no more than I would consider normal, however the exhaust tips seem to be white on the insides (pic below). Lastly, I do the same for cold starts. As soon as the rpm drops I go and stay under 3k till warm. I live in SoCal so the coldest we ever see is about 50F but it does get rather humid sometimes (~60%) I'm also not familiar with the winter start/charge battery but I'm assuming it doesn't apply to me since this car is my daily and we don't have real winters here in LA.

Ther is a cloud or puff. Gosh at 170k it could be a few things that are growing tired. I’d probably take it to a knowledgeable indy shop as I’m just guessing this far away… could be scoring but it’s hard to say. They could run a scope and decide from there… that’s what I’d do. semi normal: manual states it could burn a quart every 1000 miles… I’ll have to look again but it’s something that doesn’t seem normal to me. I have a 987 and 997 and both don’t seem to burn much of any oil and I put about 1200 miles a year on each (sadly)

sorry, the 170 was a typo, it's 107. Thanks for the tips though! I do worry if it's the injectors that a shop wouldn't be able to properly diagnose it. I've never heard of injectors causing oil clouds like that but I'm not a tech so who knows.

Lol, you can see my 987 in front of OP's (thanks for holding onto it buddy!). On a more serious note, as I know OP's car irl and helped him inspect it pre-purchase, the cylinder sleeves were score-free earlier this summer. A proposed theory by f6i and another mutual friend is that if the engine is running lean there's a chance of scoring, hence OP's worry about the injectors. The service manual dictates fuel injector replacement or cleaning around 100k miles, so it may make sense that the injectors might not be as healthy as they used to be. Afaik Dinky's car isn't misfiring or running poorly, so that may be a moot theory.

I had a high mileage Boxster S that used to do 1000 miles per litre. I had it borescoped by a very reputable indy shop who said it was fine. In the end I concluded it was the bores becoming ovalised.

Well over time the tolerance isn’t as tight as it was when new and could be a little blow by from natural causes.. I’ve seen that on other cars.

Worn valve guide seals could also be contributing to the blue smoke on start up. Check the spark plugs too to get some idea on quality of combustion.

Absolutely !! pull plugs.. they tell a good story on a/f conditions

The OP may need the 987 Motorsports AOS . If his car as a deep sump like LN sells with a windage plate, The return oil hits the plate and in high g cornering sends the oil up the walls into the OEM AOS . The original design was not made to take oil wash downs back in 05 when the engine was developed from the 996 M97. LN windage plate should have somesort of oil dams to prevent this return oil slosh. I had two OEM AOS go bad shortly after the install of the deep sump. Had my shop order the Porsche Motorsports AOS which fixed the oil membrane cracking from the oil down. OK its $1800 but it fixed the problem. I don't know how you use your car, but it seems you are sloshing oil up the sidewalls of the sump from high G cornering. There is a 996 Motorsports AOS available but it needs modification to get it into the correct alignment for 1/2 the cost. It also has a different air/oil membrane (older model). The 987.1 Motorsports model also reduces oil smoke and droplets from being ingested into the intake plenum. I run Mutol Ester V 300 Competition oil. No ZDDP involved in its additive package. ZDDP can clog up the cats as well as attach to the cylinder walls. Out M97 piston skirts rub on that ZDDP layer and wear away. I'm no fan of ZDDP in M97 engines. The engine just sounds smoother running the ester based Motul (timing chains, tappets, rod bearing) and I have 0 usage between 4000 mile refills into my 10 1/2 qt. sump. I also use LN screw on filter system which give more pressure to the oil system. I use a 996 air/oil heat exchanger, which is 40% larger and just fits under the induction tubes. This unit works to heat up the oil faster on start up and keep it cooler on the track.

Wow, a lot of useful info here. I have a few notes: 1) Yes I do have the LN engineering deep sump with baffle, but I'm confused about how the windage tray would cause oil to go into the AOS. Without the sump, the bottom of the pan sits in the same place as the windage tray, so wouldn't the results be the same? 2) Regardless of my lack of understanding, it would seem that you are right about why my AOS's keep failing and I guess I'll have to get something better. I saw you mentioned you use the 996 AOS, is that the stock one or the motorsports one? I'm not ecstatic about spending $1800 for something like that so I'm interested in alternatives. Maybe I could even run a catch can between the AOS and the plenum to decrease the issue even more. 3) Thanks for the info about the oil. looks like Ill be on the lookout for another oil as well as a screw-on filter adapter since my car is my daily/autox toy split roughly 50/50. The oil you use is unfortunately a bit too expensive for me, do you have any other oil recs? Preferably something on FCP so I can warranty it. Thanks so much for the advice!

I have a 987.1 Porsche Motor Sports AOS for $1800. The 996 Porsche Motorsports version does require some modifications and is an older version of the 987.1 MotorSports AOS . The AOS sits atop the sump and provides the necessary vacuum to suck out the oil droplets and smoke through a hole in the top of the sump The windage tray is a flat surface and the engine oil return lines empty directly on top of that flat surface. So when the engine is really singing, its pumping a lot of oil and returns to that flat plate, eventually dripping down into the sump below from through the open windows on top of the baffle. The sump is divided by the X-51 bafflel with rubber flaps to prevent oil from sloshing back and forth. The windage plate has no baffle to stop the sloshing though the top windows and oil can get around the x-73 baffle sides. So my time line was to use the OEM setup, which I did for a while without AOS damage. Then I got the notion that I wanted a LN deep sump with windage plate. After the install, the next track event, I covered my OEM AOS with oil through the slalom portion of the track. Back in the staging area, I smoked up the place. Engine seems to run ok, just a lot of smoke. The next run was more smoke and that run was my final so I limped home. The oil event finally stopped, No oil smoke on startup the next morning. The next event though the same situation happened, which caused me to stop running as other event participants suggested a new AOS . So, the next week, I called my shop and asked them to recommend a solution. They called LN and then talked to me about the 987.1 MotorSports AOS as their solution. I agreed as it caused me a lot of frustration and irriation knowing that somehow I had modified my sump which then caused my AOS problem. After I got the Porsche Motorsports 987.1 AOS installed, no AOS more oiling issues. I did talk to George at LN about this situation, but he didn't see a direct connection with adding the LN deep sump and windage plate to the increasing risk of oiling down the older OEM AOS 's. I did tell him that the Porsche MotorSports 987.1 version of AOS seemed to solve the oil down issue. He told me that they recommend this fix to anyone who orders their LN deep sump with the windage plate. The motor oil is extremely important to our frail motors from a oiling point of view. LN suggests their DT40 or XP-9 with ZDDP. ZDDP which is an oil additive, causes build up on the catalytic converters It also causes build up on the cylinder walls. In most engines what run metal pistons that scrap the cylinder walls, the build up is scraped away. However in the M97 engine, the piston skirts are coated with a plastic matrix that prevents metal to metal contact. The ZDDP buildup on the cylinder walls wears the plastic matrix off the pistons skirts and bore scoring starts occuring. After doing a lot of research over the past 4 years, I found that the Ester based Motul works best for me. There were an hand full of hard core racers still using the 987.1S setup who had over 100 track days without a blowup using Motul V-300 Power 5W-40 on Planet 9. I just noticed this occurance. Other engines like the 9A1 version, do not have the plastic piston skirts and soft cylinder walls. That engine can use the DT40 or even better the newer DI40 for direct injected motors. Motul recently changed their offerings of the Motul V 300 Power 5W-40 which now is only available in their Competition line. So, for the past year that is what I am using (Motul V-300 Competition 5W-40). I noticed a distinct difference in reduced timing chain and valve tappet noise last year when I changed over from Mobil 1 FS 5W-40 winter or FS 5W-50 summer. What I am trying to achieve is to prevent bore scoring and #6 rod bearing scaring do to oil starvation. These are two entirely different issues to look at. I did not even mention the IMS bearing, but that is because I have noticed the 987 M97 engine having very few failures. So, end of story here is that you may only need the Porsche MotorSports AOS. Others have tried to go through multiple OEM AOS's due to the initial cost of the Porsche MotorSports version. They change out their AOS frequently and add the oil catch can. The screw on filter is further protection against oil starvation in that the smaller filter reduces oil back pressure less that the OEM paper filter. So, when you are having a long high G, high rpm corner and have some air bubbles in the oil, you need as much oil pressure as possible to maintain the oil film between moving parts.

Sounds good, Thanks again for all the info! I spent a long time doing research on what oil to run and it seems like you condensed all the info I was looking for into one post. Much appreciated! I'll get the motorsports AOS when I have the financial means to, until then I can live with a smokey start-up. As for oil, it seems you're right about the Motul, I'll see if there are any cheaper alternatives but maybe ill just end up using it. Really good to know about the plastic matrix and ZDDP though. I've never heard about either of those before and knowing that will help me make more educated decisions going forward.

Another (possibly cheaper) solution is the Ultimate AOS ( Ultimate AOS ) rather than the Motorsport AOS. While I have a 996 rather than a 987, they also suffer from the same issue. I went with an Ultimate AOS with the Extreme track duty drainback and it resolved my issue, while a mate was having a similar problem and had his car booked in to get a Motorsport AOS installed due to his having the same symptoms, only to be told by the mechanic when he took it in that he already had a Motorsport installed! He went ahead and had a new Motorsport installed and it did seem to resolve the problem, but obviously sometimes the Motorsports fail, too.

Wow, I had never even heard of this! Better performance for half the price of a motorsports AOS. Sounds good to me! EDIT: Wait, this is literally just an AOS with a catch can and a flow regulator inline before the plenum. Just like what I was thinking to do, very cool.

DinkyHatchback - The 996 Porsche Motorsports AOS has a different membrane than the 987.1 version. The 987.1 version catches more oil smoke than the 996 version, info from the LN guys. For some reason LN never suggested a catch can. But again, they upkeep/maintain 10 cars for different race teams.

By catches more smoke do you mean creates or prevents? IE: is the 996 motorsports AOS better or worse than the 987.1 ? Also LN seems to endorse the ultimate AOS which is ultimately just a dressed up aos + catch can so it would seem there is some validity to their claims of functionality.

I wonder on what change was done on the 981 AOS as I do not read problems posted in P9 forum. The 981 is getting 10 years old since market introduction and AOS holding up well.

Probably the same change that was made to the 987.2 engine AOS ' - you don't hear about issues on those either, and they are getting to 14 years old now.

I am mostly concerned about the 987.1S Cayman . The Ultimate AOS really is positioned against the 996 models as the engine in backwards and the AOS is very difficult to access. The M97 987.1S OEM AOS is not that difficult to access especially if you have the correct long nose bent hose pliers. With those pliers and a handful of normal tools you could do pit stop repair and replace the AOS with a failed "flow control diaphragm" when you ingest too much sloshing oil. You could be black flagged for this oil eruption from the tail pipe. On the street, I have rarely read of canyon driving causing a bust of oil smoke coming from aggressive driving. However, with new tires RE71RS from Bridgestone aimed at the gentleman's sports car driver, higher G loading can occur. As Don points out that 987.2 AOS seems to work very well. My question is, is it better than the 987.1S Motorsports AOS . The direct injection engine in the 9A1 models have more need to refine the oil smoke than the M97 engine because the smoke can cause carbon buildup on the intake valves. But the M97 somehow gets oiled down more. Maybe its just the flow control diaphragm in the 987.2 has been redesigned to act more like the Motorsports product. LN and others have not commented on the difference. Even the Ultimate does not go down this road, rather they claim the amount of time required to exchnage the damaged AOS in a 911 as their main feature. Not any wording about the M97 positioned in the Cayman especially with a Porsche MotorSports 987.1 AOS , If anyone has detailed info around the difference between the 987.2S AOS and the 987.1S Porsche Motorsports version, let me know and where did you get your information. In this conversation, please do not drag in the 996 Porsche Motor Sports product. The 987.1S Motorsports AOS is physically different and newer in design specific to the Cayman 987 mid engine design than the 996 version. Just a quick thought about the difference between the 987.1S Motorsports version and the 987.2S version, keep in mind the 9A1 engine has 4 head oil pumps while the 987.1S has 2. When I had my 987.1S Motor sports AOS installed, Cantrell Motor Sports changed over the two head return OEM lines to larger, more robust, return lines to the MotorSports AOS . I commented on these big return lines back to the AOS . They said that LN just suggested that the frothy head oil needs more line interior dimension to vacuum as much air impregnated oil as possible out of the heads. I asked about adding 2 more return oil pumps, LN and Cantrell said those tandem scavenge pumps are not necessary due to the 987.1 Motorsports Version robust flow control diaphragm that can take the frothy head oil that the 2 remaining head oil pumps do not suck out and return. So Porsche knew about the frothy head oil issue and the best way to evacuate it as a stop gap, until the new 9A1 engine design in 09 with 4 head oil pumps. This conversion was covered 4-5 years ago. So, the offshoot is the 987.1 S Porsche Motorsports AOS is covering the oil evacuation from the heads that the 2 additional head oil pumps are now delivering very well. There is a high cost to the 987.1 MotorSports AOS , but realize its asked to do much more than the 987.2S AOS is asked to do.

Pulling this back up to the top. Any recollection of which lines Cantrell used to upgrade the two head return lines to the 987.1 motorsports AOS on your car? In case someone else (like me) wanted to replicate that on their own car.

GLTHFJ60- I will ask Colin Cantrell about the head return line diameter today as I have my car in for a list of stuff to do before the season starts.

Not just the diameter, but the parts and/or line assemblies used would be most helpful. Push-lock with adapters, pre formed rubber, etc. Thank you sir.

Sorry, but Colin was busy and had just a minute to discuss the suspension on my car, which I was paying very good money to have done. So that was were my direction was. You have to remember the Motorsports AOS was installed in my car 5 years ago. Seemed that the technician did a great job on the alignment table, trying to dig into the castor measurement to bring it close to 8.4 which happened. Camber back to -2.5f and -2.4 r, so more of a street setup to accommodate my new RE71RS tires . Maybe in a couple of weeks I can get back to Colin for the next steps re, I am trying to have PCCB total systiem installed on my car.

After reading this post today, the reason for the larger return oil lines were in part due to the fact they broke the long one due to fatigue. Then they had a conversation with Charles (LN) and used the larger return lines. One line looks ugly coming across the top of the engine into the Motorsports AOS . But the end result is no oil downs from this system, even with the flat LN windage plate. I have purchased a Hartech deep sump, which should allow better protection from oil starvation in high G cornering as shown by Slakker detailed track work on ******** under the topic 996 oil pressure instability.