Third track event and now AOS

So I have been enjoying my C4S at Waterford in Michigan and during the last open track day lots of embarrassing smoke. Pelican to the rescue and now my Monday will be spent repairing it. I have the part and the skill just need the time

What tires are you on?

Dropping engine 3", removing manifold bolts prior to removing plenums, and using a new clamp for the baffle helped me out a ton. Also, I used needle nose vice grips on all of the hose clamps.

Did the smoke occur on track or in the paddock starting up after sitting between sessions? The former may just be overfill or it might also mean you need to address the oil starvation issues. The Gs on certain turns can draw oil away from the sump requiring a deeper pan and baffle. The latter is normal for track use. This happens to me 100% of the time especially with the R comps. If you can't pull off your oil filler cap with the engine running at idle then your AOS is toast. Otherwise it seems like normal consumption. Check the level with the engine dead (overnight) cold on flat ground using the dipstick.

The smoke was real bad on the track over an off camber right hand turn. afterwards in the paddock smoke on start up , oil level was fine at the stater of the day. is there a recommended deep sump / baffle kit that would be best

I have the Ln Engineering Baffle kit on stock oil pan on one car and the FVD deep sump kit on the other. Both seem to work really well.

I am running proxes R888, I mention it as the question was asked. Looks like AOS is just at the start of going bad but I also need the oil control update as well. Thanks for the comments

AOS is not to be taken lightly. It's recommended to replace it every 3 years. With number of people that have lost an engine to it, including one of my best friends, it's one item I don't mess around with.

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Doesn't it show symptoms of failure before being bad enough to lock your engine? If so, it seems like an expensive PM item.

My buddies car starting blowing smoke out the back. He pulled over and had it towed to the dealer. Turned out it had hydro locked. $20k for a dealer installed crate. Ltusler lost his first FSI engine to a 4 year old AOS that was on his schedule to proactively replace. They have since recommended replacing them every two years for track cars. It's a $150 item that take about 12 hours to replace you first time, and about 6 hours the second time.

Update, AOS installed took better part of 4 hours going slow and being careful. having a hoist in my garage made a big difference for access I am sure. Next step will be to order a x51 style baffle and get that installed before the next track day later in July so i avoid a locked up motor.

Nice! FYI, rmeuropean has the recommended loctite 5900 and also replacement bolts fairly inexpensively.

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AOS r&r is a pain especially on mkII's. Did you run into any issuses with the AOS bolts? BTW, have you fixed your charging/battery problem you had earlier?

no issue with AOS bolts other than access as you eluded to the job is a pain. I have not found my battery drain yet, basically been using the battery tender to keep it road ready and not made the time to tackle it.

So next time one of you drops the engine, install the Motorsports version, expensive I know, but the problems go away.

would motorsports version still be recommended to change every 3 years?

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Exactly. It's not really the age or wear per se but the weak diaphragm the regular AOS is expected to handle in track situations. It's simply too weak for it. Obviously the diaphragm and associated parts will weaken over time due to heat cycles, aging, etc which also doesn't help the situation. Just so we're not seeing everything one sided, there have been numerous peeps with blown AOS's with fine motors after replacing AOS with a new one. However you're always going to get some guys that just get unlucky with a failed motor in the process too. I hope the AOS doesn't get people into internet hysteria like the IMS, Bore Scoring, etc. IMO, just ignoring or passing off the puffing of smoke after auto-x's and letting it subside before doing another run really isn't ideal in the long term. It's obviously puffing for a reason and that buildup over time could have some detrimental effects on the motor. Motorsport or homemade PVC system is the way to go for track duties.

Alpine is right. No hysteria need apply. In my case I had just finished T10 at BIR during a race, its a pretty high speed left hander leading on to the main straight. It all let go in third gear at about 7k. It pushed the oil into #4 and then kerblammo. Piston exploded, rod broke, hole in the top of the case, very messy.

FYI, I inquired about using a Motorsport AOS in my new build and was told they go out as often as the standard AOS. Not sure if it's even an option on a '99 though. Good to know the story behind your failure ltusler. Thanks for chiming in.

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This is false and I would disagree with this. I'm not aware of anyone posting here of a Motorsport AOS failure. You can fit Motorsport AOS to all 996's but some just require a bit of modification. It's documented somewhere here.

how many here run a motorspsorts AOS and how long have they had it?

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I'm just going off what the man told me about the reliability. I have no experience either way. Ya, I looked into but there was still a question on how much modification was required and if I recall it was a really tight fit.

I'm thinking of adding an oil catch can in line between the AOS and intake. Haven't found a lot of info on it yet but seems like some pretty cheap insurance.

I missed the fact that there was a Motorsports version of an AOS and installed the stock one already. Not sure if I would have wanted to pay $800 anyway. I did however order an X51 style oil control baffle so I am expecting the two items will address the issue without further incident for about half the price of the Motorsports AOS itself. More to come when I hit the track at the end of the month

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I have a X51 intake, its metal. and we had to fab up a J bolt and a hold down tab to secure it. The MS AOS could not rotate so the bolts would line up. Pretty simple if the engine is out and on a stand. I may have an advantage since my engine does not have the AC or PS pumps to deal with so the engine/tranny drop and install go pretty quickly. I am down to about 2 hours either way.