Day at the track ended early...smoking engine?.AOS?

Out at the track yesterday and my son saw big puff of smoke on the straight right when I shifted at 7K rpm from 3rd to 4th. Then I noticed the same thing in my rear view mirror on the back straight shifting from 2nd (at 7K rpm) to 3rd. So I came in early. When I was in the paddock the engine was idling and I did not see smoke so I shut the engine off. Then I started the engine after 30 minutes and a big cloud of smoke emerged and smoke (albiet not as badly) came out of the driver side tailpipe (and it looked like nothing came out of the the Passenger side). As a result I decided to retire the car for the day to perhaps get it checked. I drove home (1.5 hours) and no problems even when idling. I restarted the car at home and no smoke at idle or revs shortly after I returned home and then once again the next day. No smoke. Some key points. This was the first time the car has been pushed since coming out of storage. In addition, the oil was just changed a week earlier and filled to the top bar. My friends tell me that is likely the AOS was dumping oil since it was filled on the high side particularly as the oil temp gets high and expands. What do you guys think it may be and is the car OK to drive again on the track? I am going to get it checked out either way.

well I am getting my AOS done as I type, I noticed a similar pattern when changing from high revs, and cold starts in the car park. Also had incredible suction on the oil filler tube when the car was running. Also this funny chirping sound at idle. Yours could be simply filled to too full of oil, combined with high G corners ( reading on here they suggest deeper sumps X 51 for track work) or an AOS on the way out. Issue really is placement of the AOS. its a real PAIN, to change and a fairly inexpensive part. There is a motorsport version if you intend on tracking often might be worth while.

For what it's worth I've seen the same thing happen to someone else at the track, great big cloud of smoke. As mentioned there is a tool you can use to see if your AOS is on the way out your local Indy should have one.

My guess: Oil was filled too high. Put it below the top bar when cold, at or one bar below when hot.

Oil filled too high. Put it dead center on the dipstick and you shouldn't have this issue. When was the last time you changed your AOS?

I had similar experience last year at DE event. I also believe it was too much oil. Doesn't do it at all on street, and uses virtually no oil between changes. Maybe it's just me, but I find checking oil level on my 996 to be a bit of a witchcraft kind of event. It seems to vary wildly. When you say "dead centre on the dipstick" Slakker, you mean halfway between full and low, correct? Is that after sitting 24hrs? or 20 mins?

should be at half way mark after sitting 12-24 hours. measure it cold. if the oil was filled to the top and you went racing, I would try running the oil lower before worrying about anything. the fact it didn't smoke after the drive home makes me think the oil vapors have been burnt off. always good to let your car idle and cool down a bit after some laps.

Thanks guys...this is super useful. I think this is the right assessment. My oil level on the dash showed filled to the top when I started....I am sure this is likely what happened. I will talk with my indy as well to confirm but I think worst case is I need to drain some oil. To answer the AOS question on when replaced last. I think I only have 300 miles on it at most. Thanks again.

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If the car is on level ground and the engine cold -- having been off say overnight -- and the oil level is at the top, max, bar when the oil is hot then the oil level will be too high. This elevated oil level can exacerbate the propensity for these engines to smoke a bit under extreme (track) usage. If the oil level is too high you can remove some oil. Where you had the oil changed might be the place to take the car. OTOH, the engine should not leave the shop with the oil level too high. If it does this is a sign the shop doesn't know what it is doing, and I'm not sure I'd want to put the car back in the shop's hands. I would run the oil right at the max line measured with the engine fully up to temperature and on level ground. For track driving (and in my opinion even for street driving) one wants the engine to have a full fill of oil -- right at the top but not over (when measured hot) -- to help reduce the chance the oil being ingested by the oil pump is as free of air as possible. If the AOS was bad there would be other symptoms -- wavering idle, possibly a hard to impossible to remove oil filler tube cap while the engine was running, and as the AOS failure advances smoking all the time.

My indy fills the oil level according to Porsche standard quantity; the oil level then is about halfway as indicated on the dash. Dipstick same (half). Volkert

Macster, max fill line is no good for the track. Halfway point is recommended by FSI (cold, sitting 12 hours) and in 30+ track days mine has neither smoked nor starved using this method.

yup. ran my car at full mark. smokes like crazy, now run it at half and 0 smoking.

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+996

I truly hate it when some d-bag says "did you even search, bro?" - but this same thread exists over and over and over. We all know I'm a d-bag, so...did you even search, bro? Seriously, though - we all recognize the instinct to post first when you are having visions of dollar signs flying out of your wallet...but the benefit of searching instead of oh-s**t -posting is that if the question already exists, it's also already been answered. To me, it's better to read a 3-year-old thread with a reassuring answer than it is to sit there clicking "reload" over and over while praying that (a) I get a response, and (b) it doesn't involve writing a check for $20K.

I disagree. Searching, especially on the Garbage Talk app, sucks. Whereas posting returns timely and relevant information. Plus, it gives you something to bitch about besides grammar. So see, everybody wins!

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Best way to search Rennlist: - use a browser (desktop or mobile) - use google - type this in your search bar "site:rennlist.com 996 smoke track oil" - enjoy Back to the issue. Do yourself a favor and follow the advice above. I have battled oil and smoke on the track - reducing the amount of oil in the system and running oil designed for wet sump track use is the key. Half way up the dipstick + oil designed for the job.

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Well, you are fortunate but I think it unreasonable to assume everyone will be as fortunate as you. Because of differences between drivers and engines some engines will experience higher running oil levels/less air in the oil than others. These engines can be run with less oil but I still would not be comfortable. In other cases because of the driver, speeds obtained, and differences in the engine's oil budget these engines can experience more levels of air in the oil and lower running level of oil in the engine. Running these engines with less than the full load of oil is risky. Trouble is one doesn't know which engine he has or which type of driver he is. A bit of smoking is a small price to pay for having as much oil in the engine as Porsche calls for.

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Not a Porsche standard as far as I know. My Turbo factory manual calls for the engien to be up to temperautre -- hot enough to check the engine oil level (which requires the engine be idling and warm -- followed by a drain time of 20 minutes followed by a fill of 7.8l of oil and then a check of the oil level done hot. The level should be at the max line but not above it. My info is the other factory manuals offer the same oil change guidelines and require the oil level to be at the top. It is by following the proper oil drain procedure then putting in a known quantity of oil that the tech confirms the electronic oil level sensor is reporting the expected/correct level with the engine properly filled with a known quantity of oil.

I can tell you it's the same with most of the SP996 guys and the race shops. Halfway up the dipstick is ideal. Anyway, everyone can decide for themselves but I usually go with FSI's recommendation and have had very good results doing so.

There is an aspect to this common Track-Guy issue that is never mentioned. If you have a deep sump kit fitted with the extended pickup for the oil, why not run the oil level a little below half way on the original dipstick ? At that level the pickup is still immersed in a higher 'head' of oil than at the full mark on an M96 with a stock sump. This may prevent the oil foam from overwhelming the AOS ? It certainly keeps the liquid oil a little further away from causing problems.

Feed back taken 5CHN3LL... I wont post anymore to avoid feeling like I have to search everytime first. Saves even more time that way. For the rest of you, thanks for giving me the confidence I needed. Also confirmed by my indy. Will be back on the track soon.

...

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I disagree with D bag. I found this post the most helpful compared with the other posts that I�ve read and searched on the web related to this specific M96 issue. Probably because it a bit more recent / current and the wealth of knowledge has accumulated since older posts. Keep on posting and ignore D bag which is not helpful and extremely erragant and give Porsche owners a d bag reputation, even though there is only one d bag on this post. Nice job and great post. !!!! Great post!!!!!

Erragant . I like it. I'll be using that in the future.

Yup, I�ve had this happen on the track. 99% sure it is the AOS, and it goes away, but is nerve wracking until it does. edit: apologies for replying on a necro post...

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That is what i thought and then ....KABOOM! At my next track day....😢

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My thoughts too. This is one of the reasons why I installed the 2 quart deep sump. I fill only half way between the dipstick lines (when cold), but I still have extra quart+ of oil in the deep sump, compared to the normal sump.

Well, my friend, I'm sorry to give the bad news, but if this is the yellow aero coupe - then the patient is done for. Just PM me where I can pick up the rusty, non-running hulk, leave the keys and pink slip on the seat and wave goodbye. I'll handle it from here... <serious> Hope it goes ok. Sounds like a lot of oil got packed up in there, and overwhelmed the ability to separate, then dumped a bunch into the intake and through the top end.

Not sure if ya'll are aware... this was from 2017... lol

Not too sure whether your car still have the dipstick. Mine 997.2 doesn't have it and I don't rely on the electronic oil gauge because they are very accurate while they work, but notoriously unreliable and gives false reading when they act up. I always base on specified oil volume as shown in the owner's manual when I do oil change.

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Yep....as blue chip says....old news and old thread. KABOOM was two years ago....sorry to disappoint but car is healthy with a 997S engine and an additional 100hp😀

Yes, I was aware. Just trying to horn in on a most excellent C2 in the proper color. I gave it a go...

Did you pop the plenum apart to see if you have any oil pooled in the common oil pool points? If so, you may want to get that drained out - there's theoretically enough oil volume to hydrolock the engine, though smoky puffs is probably a much more likely result...

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Lol....nice try😁

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What was the reason for the kaboom? Where there any warning signs while on the track that you can look back on?

Have you looked into the Motorsports AOS,? I can run full dipstick with no issues on my FSI 4,0 Stage III. I know they are expensive, but they work.

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Every now and then i saw a puff of smoke on the track coming out of a turn once or twice per lap....everyone said its aos...too much oil. so net track day i lowered oil level to half. Same symptom and kaboom on a long right sweeper. one of My rod bearing had disintegrated. Crank shaft for that piston was completely worn.

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Were you running a deep sump prior to the kaboom? Racing oil? Just curious.

Everyone answered your question already but FYI there was a TSB from Porsche on this about reducing the oil level from 9.25 to 8.75 and then performing a DME program to ensure the low oil light doesn't come on.

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Where you doing any oil analysis on the car before this happened? What was determined that caused the bearing failure? How many miles on the motor?

Most likely oil starvation. Those long right sweepers and oil pressure drop I saw on my car is the reason I don�t track my car any longer. Porsche 996 = racecar, not.

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yep, oil starvation was the cause on the 54k miles car. Of those miles probably 20% was track miles. it had no deep sump.

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YES !! There was also a "new style" dipstick that was longer and the "full" mark was .5 liter lower and required a reprogramming of the cluster, to keep from overwhelming the AOS during high G forces. I think a better solution would have been keeping the oil out of the AOS in the first place. With all the track starvation issues that we are seeing, I'm wondering if SOME people are using the "new style " dipstick and programming and also lowering the level to half full, resulting in being a full liter low on oil?

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Wow 10k for track miles that is a lot for a street car Did you do all of those?

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no....previous owner did most of those track miles....i had car since 47k for past 7 years....i have primarily been using car for track. over the four years everything has been replaced. time every mechanical thing has been replaced