AOS 996.2 replacement..whoa!

Hey everybody…I’m replacing the AOS which is a significant endeavors. I’m reaching out as I’m stuck at removing drivers side manifold due to the last bolt being difficult to remove. See next to green tape in mirror shot. Getting wrench on it blind is a bitch( I can’t use left hand and look at mirror and using right is awkward)…and it appears it will hit the bottom of AOS. I’ve attempted to get AOS to move up and it wasn’t go up enough. I see only one bolt(new 2002 design..99610702652…no bellows) This one was replaced at 15K in 2011 and now has 33k & 13 years of use of use) I hear the UAOS is better but I am going with OEM again as I read they are improved. I’m waiting on the replacement to arrive to see if the is a bolt on the back I’m missing. I’ll also try to get as many hoses off. Popular video I reviewed seems to take AOS and hoses off as a whole. That video is of first gen car also however. They came from the top to get that last bolt off …I can’t see if it’s being blocked as mine is. Moving the AOS to the side would seem to be easiest at this point… I’d not like to have to back track and drop this tranny. Any help appreciated…Thx Hose on bottom of AOS secured with two clamps…one on left difficult to reach…one hex bolt top right Difficult to get leverage on the screw…how high it’s up took several minutes..a mm at a time…gotta turn your brain around lmao 🤣 Any tips appreciated

I’ve not done a .2 as my AOS was still working perfect when I did my UAOS, so I just blocked the vent port. I did do a .1 and, while not easy, was doable. I’m sure Skip will see this and give you some pointers from a true expert. I feel your pain though.

If you go to the advanced search function and type in "bitch bolt" , you will find tons of discussion on how to get this out..... This is ONE of the reasons I delveloped the "UAOS LIfetime" system.....so that part never needs to be replaced again and saves labor$$$ in the long run... Also, what is this "improvement" you heard about?? The Factory AOS has been revised about 6 times over the years....but none have proved to be an improvement...actually more "infant mortality" have been noticed...

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id like more info on your UAOS system please. I have researched and if I go this route will the long hose that goes from drivers side to passenger side of OEM system still be used. I ordered a new one as this is where the leak was occcuring . I do not track this car. As part if their IMS package AOS was included and there was no evidence of the original being bad. Nevertheless I got 30 thousand miles of of an OEM one …it took 11 years to cover that distance. It would make it easier for the next owner. Thanks for your comments…it would be easier for me or future owners to try this UAOS…”bitch bolt”. How appropriate…I said that worD many times over the last 48 hours…LMAO about an AOS. isnt bellows the older design yet the UAOS uses one to install if I’m reading correctly? And are there customer modification that must be done during install or does unit come “plug and play.

@RTSC4S The UAOS System is plug-n-play...no mods nesseary. Yes you can sill use the OEM cross-over breather tube... Here is just a quick 10 point list of the Benifits ,I've been working on a more comprehensive list and Q&A list, but things get in the way...lol 1. The UAOS costs less than the Motorsport AOS and outperforms it by a wide margin. MS AOS for 996.2 $900 MS AOS for 996.1 $1600 .. 2. The Factory AOS is indeed a frail part, it have been revised by Porsche about 6 times (seen in part number revisions) and is still as frail as ever. I have replaced many engines under Warranty / Extended Warranty from Hydrolock. When Hydrolock occurs under Warranty , Porsche will replace the engine. They wont even clear the oil and crank the engine see if it knocks or has any other symptoms, the reasoning being it could have a "slightly" bent rod and show no signs, symptoms, or noise, and still be prone to early failure due to a rod that is no longer perfectly straight, and that dissemble and inspection would just be extra expense. We have seen at least one to two Hydroloocks per year in this form for the last 10 years. Below are just a couple of photos, one from FSI on a new engine that had an early AOS failure, one from an unnamed shop out west.. There has been thousands of AOS failures and some owners have had multiple AOS failures in consecutive years. 3. The UAOS has a 2 year Unlimited Waranty on all parts, and a Lifetime Warranty on the AOS. The AOS used in UAOS is made from Polyamide66 /35% glass filled. A Study of this material shows that under extreme temperature and pressure is has a life expectancy of 35-47 years, under Automotive use I would be considered a Lifetime. The part that fails is the FLOW DIAPHRAGM which in the UAOS is modified to eliminate its propensity . 4 . In the UAOS the FLOW DIAPHRAGM / REGULATOR is encased in an inexpensive part that is located in a very easy to access location., This makes any service easy and labor effective and saves $1600 dollars in labor in 9 years if you follow the 3 years rule. 5. The UAOS with the optional high mileage/ Extreme Track Duty drain back can drain back oil twice as fast as the Motorsport AOS. The Motorsport AOS still uses the Factory drain to get the oil back down to the sump, The UAOS also uses the factory drain but includes a Second Drain to make the drain back twice as fast. 6 . The UAOS has an Accumulator that works as a secondary oil separator to ensure no oil makes it to the intake manifold.Pluss copper mesh filters for extra effficiency. 7. The UAOS has a Micro Controlled Infra-red warning sensor in the Accumulator to warn of system failure or excess oil accumulation to stop the threat of Hydrolock. 8. The UAOS is so efficient ,the engine can be ran "over-filled" with oil to help mitigate oil pressure instability on the Track. ( with Drain Back option). 9. The UAOS is all Plug and Play wire harness connectors simply plug in, all custom aluminium/Nylon hoses are hand built to fit . 10. The UAOS application has been expanded to fit not only the 996, but the 997.1 and 986 and 987.1 engines.also.. BTW the UAOS kits are on back-order for 3-4 weeks, but LN Engineering has some on the shelf..

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IIRR, PT3 offers a very nice 'heavy duty cross-over breather tube' ..?

I would never go through installing a stock AOS when the UAOS is so far superior and easily worked if it ever does fail. It is truly a great design and how Porsche should have done it first time around.

Well fellow enthusiast I totally get that the UAOS is superior design and can only increase value and reliability. What’s not motivating is tackling getting the OEM off so now that the “bitch bolt(BB)” had been conquered. “I got a whole new AOStitude”…. Many have suggested that moving the AOS out of the way made the BB more accessible. It is visible in a mirror shot pic1…Once AOS shifted out of the way I could reach my hand with a tool right on top of the BB. See pic2 of the back of my hand holding bolt. This best done from below…pic3. Now I can go after the long breather hose while waiting for UAOS to come . Seems to me it should be possible to just detach it from right side of engine and thread through. Since mine is leaking I won’t reuse it. If cutting out doesn’t work …I’ll remove the passenger manifold after the compressor and power steering reservoir out if necessary. I’ve done that before doing the power steering pump 8mm innermost holding 996.2 AOS in place…once removed AOS can be shifted Got the BB by the throat…like a lion on a impala..lmao. Mirror image …my hand coming from below Mag tool keep screws from falling once all the way out

Another day of progress toward what has now turned into a Ultimate upgrade. …Good job and appreciate Skip spending some time consulting with me on his product. On procedure…take the coolant tank out and lower the engine…necessary evils Both manifolds removed to get the long S hose. Found the small hole in this hose..very obscure.Pic2 Definitely label…some kind of ID pics to help reinstall screws and hoses…etc The spray of oil apparently “soaked” the harness connections pic3 going to coils …most likely what through 4 and 5 misfires…oddly even though coated with oil residue did not get a code on 6. I’ll see once on the road if code follows the coil pack after cleaning them up. Opening the harness up to check for contamination hopefully will prevent further damage if any. I didn’t escape having to replace the oil fill tube which had a slit in in and “snapped in two” when I moved it to remove long hose…don’t know if vacuum leak has been occurring there…20 year old soy based plastic Is that a rodent bite? Oil was spraying out here Lots of oil on that connector and harness to clean Very wet there …and there This is a wishbone …last year I found a skull of a bird while repairing light harness chewed up by possibly the same culprit that “stashing bones” in da Porsche we have a lot of cats that roam my neighborhood…Siverado had to block any entrance under the house…have found their business area while repairing the furnace. I wouldn’t be surprised if a warm 3.6 made a nice hibernation spot. The AOS I removed had 20k miles on it. Installed when IMS was done at 15k…there wasn’t any issue just parts of the requirements for Raby’ outfit doing the IMS..pretty much a testament they the OEM aren’t adequate😒

As I continue and wait for the arrival of UAOS ordered today evaluation of possible consequences of oil contamination of cylinder on passenger side bank. Slightly more oily film around no5 coil than no6. Car is parked on slight rear down grade so may have travel rearward to 4 and 5. Wear these 15k spark plugs look within normal range…grayish tan however there is some “dampness” on both. 5 ( which threw a misfire code) more than 6. I’m going to switch the coils around of 5 and 6 and see if code comes back. Next step possibly new plugs Bosch Supers condition. Which plug do most folk like?

Is this UAOS applicable to 997.1 models ?

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I like either Porsche branded or Beru. I previously had a bad experience with some new Bosch plugs on my 996.

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@BHMav8r yes, there are 3 kits availible for 997.1 cars.. UAOS-AL-997.1A to fit 2005 997 with 3.6 engines before engine # 695 08696 UAOS-AL-997.1B to fit 2005 up 997 with 3.6 engines after engine # 695 08967 UAOS-AL-997.1C to fit 997.1 with 3.8 "S" engines... All the models are availible with Optional Track Drain kits...

Very good to know - thank you.

�Thanks Ptech for all the points on the UAOS..let�s put a decal together. As I wait�wait�wait�wait for the Erling manifold gaskets. I will contact a local dealer to see if they may be in stock. One would think that with the popularity/availability of these �entry level 911$� more parts would be �in stock�. Pcar Dealers Dealer pricing turns this foot into a SprintBooster�he don�t need launch control Everything is a 3 plus day wait. I�ll call and check and maybe get lucky. I�m working the club race at Michelin this weekend so off today resting up.it would be great to get some traction putting right side if top end back together. Couple of while you�re in there�oil filler tube cracked�pulled on it a little and just split open�vacuum leak potential gone. Your best friend is PB Blaster on 20 y/o bolts no matter how small. I�ve never had an issue with Bosch plugs �used in all 7 of my P cars over the years dating back to 1991 924T

Fun weekend at PCA225…I work the grid and big fun.! I attempted to see if any of racerscwhere using Motorsport AOS or ULTIMATE. NOMLOVE…🫤 Taking care of Since I’m in there which turned into repairs…Oil fill neck…996 has been upgraded to 997 part no. Discovered the power steering return line is weeping. There is a tiny bit of movement of line in red lock ring and keep getting pooling over night. Steering had been groaning while parking. Sourced some o-rings….mine were in good shape. It appears green one is nBr; more flexible and black one is stiffer …increased parts nitrile . My line was not smooth around the end so zi cleaned and sanded to 80-120-400 grit smoothness and added a thinner green o ring. There is no movement now as many have suggested using an additional oring here. It is not leaking but I will watch it and change lower reservoir if it keeps leaking. yay…UAOS arrived today!!! If no leaking from PS line I will begin installation of this ultimate puppy… Cup cars rule!! Love the 964…wow! Cleaned and sanded the Power Steering return line Power steering washers…different rigidity Chains look pretty clean UAOS…very understated packaging…

@Porschetech3 I've sent you a PM

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Since you are in there, I would replace the oil pressure sensor with a new one, they tend to go out and a %^% to get at

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I�ll look into that�thanks for the suggestion. The power steering line is tight but still weeping. I don�t trust that the 3 washer set up is working. My line may need more cleaning to smooth out . I had stretched the red locking pin getting it out so a used one doesn�t give me the confidence that the pump will be sorted. I�m going to re-sand the pipe�try two washers only as per OEM and if no improvement will replace the lower reservoir with a new unit $117.00� the rings are fitted at factory(wherever they are made). I�ll install the UAOS and coolant tank of left side of engine while waiting for reservoir�look at oil pressure sensor�Thx

Hello fellow enthusiast…it’s been a fruit fall day getting a major part of the Ultimate AOS installed. Kudos to Skip …da Porsche-tech…we been on do phone and Emailing to walk me through this install. For me with an background in HVAC and reading schematics it helps me to have it laid out so ai can see what it should look like compared to OEM. See Pic1. After establishing the roadmap. I asked Skip if a CAD illustration with the pieces exploding apart showing arrangement. $$$. I also found the AOS from Chris Altmeyer who is doing a 996.2. This install also seems to retain hose 13 and coupler 18 which Skip’ kit eliminates. Not sure why. The AOS must be loosened at its attachment …(listen carefully) FROM BELOW… it’s easy to get to it and the “Bitch Bolt” YES… ITS accessible from above with the motor lowered as well. Removal of coolant tank is helpful as well. See pic2 and 3. im gonna hold on UAOS because while in here power steering leak needs addressing. I attempted to reuse red lock washer and add a third washer. I keep thinking it’s still weeping although feels dry around hose. I think I could clean the hose better so I did. I discovered the more rigid washer was split so I’m going to get a new lower reservoir with pre installed washers and Orings pic4 To be continued… I have a 74 mm IPD plenum that needs a new home…like new $499…it’s on eBay. I’m gonna go to larger 82mm and throttle body. Better than new at $899..pic5 Purple lines show OEM to UAOS Like new Out the box the line is curved but it can be bent to appropriate shape by warming with a heat gun Really cleaned that power steering hose up80-230-400 grit sandpaper Access AOS and Bitch Bolt from below even on the ground. Folks with a lift

Anybody who has done an install on 996.2 and can shed some like on how to do the UAOS harness hookup. As was explained isn’t obvious to me how The sensor element switch (1)is done. I don’t see how this element will connect to the harness? It was told to me…”unplug low coolant sensor…plug into UAOS connector(2&3)”. This is what isn’t obvious…the element does not appear possible to be separated from its harness in order to fit into the UAOS harness. There are no instructions from the seller so hoping someone who had installed one can take a pic of their arrangement it would be appreciated. look at picture…what makes sense for the element (1)…be inserted into (4) and the (3) will connect to (2) but the element seem not able to be just popped out unless I’m missing something. Any help appreciated?.. OEM is 1-2…UAOS is 3-4 …inventor says connect this ….

Plug 3 into 2, and 1 into 4. 1 will disconnect from 2, you just have to push the appropriate tab. -Tom 2003 C2 with UAOS and UIDS

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Thank you�there is a tab inside there that didn�t appear to come out easily and I didn�t want to break it�I will make a second attempt now that I know it�s the correct tab to open.👊🏾

If I recall correctly on 2, you press inward on the tail of the tab, and then pull apart. -Tom

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That did the trick. My 20 year old tabs are brittle and did crack but it should still function. Changeover valve should be same arrangements it should all be downhill getting to final setup. As I understand one of the advantages of this system is the ability to �service� AOS system. Is the infrared system a warning that oil has been collected and need to empty? Is that the purpose of the blue coupling? Hopefully power steering lower reservoir will come in and can get this saga completed�lot of while you�re in there stuff adding to delays. I could have car sitting somewhere paying someone to do the same thing so the bright side�no labor $$$ and learned some stuff. Good to have friends

If you mean the blue coupler (#2) in the diagram above - that is from the car harness, it is the signal for the low coolant light. #1 is the low coolant level sender/switch. The infrared system will trigger when enough oil has been collected in the accumulator to block the infrared beam. That will then mimic the low coolant flash as it is wired into the coolant level wiring (#2). So when you get the slow flash on the coolant temp gauge, you either have low coolant level -OR- you need to drain the accumulator. If you have the UAOS with track drain installed - you should never have accumulation as it drains back to the oil fill tube. -Tom

Yay! Ultimate AOS has been installed(..and it looks like the set up in all the articles�I shot picture to Skip to clarify any mods to expected set up. I had to do some heating and shaping for alignment with the large hose from AOS to line up to rear of Accumulator. It is made to bend and shape as needed to fit. Turning the check valve (green) in the opposite direction resulted in me pulling the vacuum line from flap valve on rear plenum. This contributed to vacuum leak. After refilling with coolant using Airlift�took about 20 minutes I went to crank car up and it keep turning over but immediately dying. Consulted with the guru and was told �every body get a vacuum leak re-installing the rubber sleeves on the plenum so I went to adjust mine. The brake booster on drivers manifold where the additional bracket was added was not held down all the way with th3 tamper proof bolts? Fixed the vacuum leak and first drive in a month to get the fans to kick in�..YAY The additional issues with power steering fluid reservoir leaking fixed�.misfires�all sorted. Now I just need to sort the ghost in the passenger side mirror which had a mind of its own. Maybe time for a reprogramming. When installing front plenum�set up UAOS installed From driver#side view Lots of support from designer helps treamendously Looks OEM�WOW

UAOS saga..season 2…Murphy’ Law is real. The UAOS install was completed(…and proven to be done properly) with a few historical side effects…one being vacuum leaks from maligned plenum sleeves. Mine was unique in that a new manifold gasket replacement must have slipped out of the groove and was peaking out like a turtle 🐢…it’s actually green(pic1) detected with a smoke test(possible to homemake a smoke machine but they are available cheap on Amazon $40-60. Work great but stink! Also noted vapor at the brake booster lock washer…probably age related so will address that one with first some thread tape or replacement…$7 part. I got some smoke from rubber plenum couplers so will re-tighten those. I had been driving trying to get “Readiness “ for emissions cause battery been disconnected for a while. Also discovered pool of oil next to oil cooler and intake housing..pic2. Hope it’s not the oil cooler…pricy. I’ll clean it up and watch.Stumped.ANY IDEAS Appreciated? ….no rock left unturned Little teen speck is where rubber tab from gasket peeking out Puddle of oil…several inches, away from oil fill tube which was replaced Some sludge around lower edge of oil cooler😪

Water intrusion made a puddle while cleaning coolant leak�smoke test condensates�interestingly enough after removing right side manifold out I discovered the gasket is supposed to peak out like that. They all do�that�s not the source of the vacuum leak unless torque wasn�t sufficient �I got a inch pound small wrench this time just to be sure. Fixed the brake booster lock washer �replace. Old one just fell off�no tension at all after 20 years. Re-routed the resonance flap vacuum line between long AOS hose and rear plenum to hold it up out of the way. Potential source of vacuum leak . On the right plenum sleeve with the use of competition OPD PLENUM I noticed a gap inside which I thought would lead to a vac leak. It�s like the sleeve is not wide enough. It does fit flush however. I thought this might lead to a vac leak so I switch to the sleeve that appeared to work better.(NOT TRUE)� you have to follow along it strange. The PET list the sleeves that fit the front and rear plenum as rear�#14 and front �#11�identical on both sides. Well somehow I had a #14 on my right front plenum. 2�#11 and 3�#14. So the solution was to track down a #11. I did and it doesn�t fit flush so going back to using a#14. The rubber is tire$ afte4 30 years so hot new for both sides So�decided to take a few picture of inside of cylinders�this camera snake isn�t that clear�blurry but smoothness maybe an issue on those wall if true�Yikes Inside cylinder�need a bette4 picture Scoring? Little turtle head sticks out on all 3 #11 listed as correct part but I had a #14 in my car which fits better I discovered that my lens strip across back of the car is broken off on one end. ..missing. It�s over $800 so ANYBODY with used one Pam me. Can�t concourse like this