Troubleshooting/sorting possible AOS issue (or maybe it is something else)
 

This thread is a follow up to my thread on my first DE event here:
http://986forum.com/forums/boxster-racing-forum/47708-getting-ready-my-first-de-roebling-savannah-ga-sep7-8th.html

I had a great time but on the final run of the I felt like it was going really well, coming out of turn 9 onto the long straight at Roebling at maybe 80 and then accelerating through 100 with WOT the power dropped out for a second or two, the CEL blinked a few times, and I dropped a *huge* plume of smoke out the back lasting for a few seconds. Power came right back and the CEL went off, but I went ahead and came into the pits early after turn 4 as a precaution. Luckily nobody was immediately behind me, but during my limp to turn 4 to pit I probably aggravated the folks behind me (sorry folks!).

I brought my durametric, and it showed codes P0300 and P0305 and P0306 (misfires in Cy 5 & 6 of the type that are damaging to the cats)

I had just changed my oil before this event (Castrol Syntec 5W40) and I believe I slightly overfilled (1 bar above the top on the electronic gauge, and slightly above the top on the dipstick).

The consensus at the track was that I overwhelmed the AOS (which was last replaced 3/20/2012 about 9,000 miles ago - I just looked that up in my service history, when I was at the track I was unsure when it was replaced, only that it was sometime in the last 50,000 miles) during the high stress driving of the high speed right hand turn/track driving which dropped a smoke bomb out the back.

I decided not to make any more runs until I got this sorted out and so I came on home (3 hr drive back home which went fine)

Until this point I have had a puff here or there during startup maybe 2 or 3 times but never during driving.

Additional information: during my first run a person behind me said they smelled/saw a thin stream of smoke coming out from the back of the car from the middle, but nobody else saw it.

My instructor said there was a possible performance AOS available (and from looking it looks like that may be available for later models?) but I am looking to get this sorted out before I go back to my next event.

I have seen several other threads where folks have had this same thing at the track, and each one seems to have a different solution, such as fill only to halfway on the gauge, one person switched to M1 0W40, some folks installed a new AOS or a newer/enhanced version of an AOS with more capacity.

I haven't had a chance to take a look in the engine compartment, look inside the throttle body, MAF, etc... and before I get ready to go in there I want to make sure I am checking everything I can.

Does anyone have any guidance or hot tips for my next steps?

Is there a performance/enhanced capacity AOS available for MY2000 Boxster S?

Should I try to have full, half, or bottom of the range for oil? (above full was a mistake, I won't do that again, and if I am still slightly above full should I drop the oil filter cover and drain a little out to get it to below the full mark?)

Thanks!

Steve

I think it would be less messy and easier to use the oil plug under the car to drain a bit of oil, or am I missing something?

I also have my oil at the top plus one bar of the digital, but on the dipstick its less slightly than full, so I tend to trust the dipstick more.

I've never had any smoke on startup, so perhaps its a symptom of the high speed and G's getting the oil into places where it ends up getting into and past the AOS into the Throttle Body more readily.

Many folks racing seem to need solutions for that, some are putting other types of AOS with separate oil drain/catches into the trunk etc

Changing the filter will drain off about 1/2 quart of oil, and is the easiest and cleanest way to lower the oil level. Be sure to use a new O-ring on the filter housing.

If you have ever seen someone try to do this, you would understand what a mess it can be, just dump the filter housing.

I wasn't sure if the o-ring was single use or if it wears out over time so good to know that I need to replace it. I ordered a Wix 57211 filter (it was almost the same price as the o-ring by itself) and will change it this weekend.

From the additional research on these forums it looks like oil at the top/slightly above the full range makes it easier to overwhelm the AOS. After I get the oil lowered there is a local oval paved track that I am going to see if I can drive a few times around and see if the problem is resolved before I drive back to Savannah for another DE.

Thanks,

Steve

I just drove the car to lunch and before leaving on the way back I removed the oil filler cap while the car was running. It came off with about the same amount of force as it does when the car is not running, and once it was open there was a whooshing sound. I believe one of the symptoms of a failed/failing AOS if excessive vacuum that makes it very difficult to remove the oil cap.

Just adding a little info to the thread. :)

I see this with engine oils that aerate too easily, which makes the issue worse, especially with hot oil.

Its also a sign that the AOS is getting weak, I mandate that my track customers change theirs every year, or upgrade to our AOS. Earlier this year I lost an engine to an AOS and it came apart at 7,000 RPM, hydro-locked and blew a piston into 10,000 pieces.

Where would I go to upgrade to your AOS? I do see one on your website but it looks like the regular Porsche one, part # 996 107 023 04. Is that it? My car is a 2000 S.

Thanks,

Steve