How to TEST THE AOS on your Porsche before you replace it!

[@uspaint]

Another great Porsche video. Thank you.

[@RuslanArdashev]

What uspaint said. Thanks also 💪

[@HelpMeDIY]

+uspaint you’re welcome! 🍻

[@HelpMeDIY]

+Ruslan Ardashev 😎

[@pjay3028]

Just a note on this for people referring to this video for help. You said on a more recent video that you should have the manometer running before you actually start the engine, and get someone to watch for a spike in pressure during engine startup, as sometimes the AOS problem only spikes the pressure on startup and then it falls back in spec once the engine is idling. Thanks for all the videos.

[@HelpMeDIY]

+p jay yes! Thank you

[@pjay3028]

​@@HelpMeDIYhi, I just tested my AOS thanks to your video. It did actually jump to 7.1 on start up, then settled immediately back to 4.8 at idle. Do you think that spike is a concern? Thanks again for the videos.

[@pjay3028]

I've just found a Flat 6 Innovations video that showed the AOS jump to 6.2 at startup and fall back to a steady 4.6 at idle and they were happy, so I'm hoping mine is OK! 🤞🤞

[@jadmann]

How about the oil gauge indicator on the instrument cluster! Mine shows at startup but I don’t see the usual elevated indicator as to oil level! Yes, dipstick checks out full but I don’t see my reading. Can you check this Aaron. I could use some DIY feedback! By the way, this occurred only after I replaced a dead battery and installed a new battery, belt, and alternator.

[@HelpMeDIY]

+Joe Davis, Ph.D. Sounds like the sensor is bad, but I don’t know anything about that sensor, sorry!

[@a7xphenix]

Every time you post a video whatever it’s on breaks, starter is going out on my 986 and you just posted a video, now I need new coils and plugs and boom you posted the video. Guess who now has alittle white smoke on startup

[@HelpMeDIY]

+Eric sorry! I’ll stop posting! 😝

[@stampedetrail2003]

Can't tell you how many weird issues cleared up after swapping the AOS, it's something I'd do again and recommend to anyone considering a Box or Cayman.

[@HelpMeDIY]

+Brian & Sylvia pretty big failure point! 🍻

[@a.c.e.7568]

I have the same unit. It comes with instructions. If you press the HOLD button for more than 2 seconds, it will ZERO the reading.

[@HelpMeDIY]

+A. C. E. Ahhh thanks!

[@briansturgill5905]

Finally got around to doing this today. Pulling a 4.12 steady. Is that good? Thanks man for all the great videos!

[@HelpMeDIY]

+Brian Sturgill yeah, thanks!

[@ericbengle]

Can valve covers be resealed on a 2000 Porsche 911 cerrara without dropping engine ?

[@HelpMeDIY]

+Eric Engle never worked on one of those so I could only guess.

[@davohadi]

Thanks for the video I read 4.18 on a 997.1 I'm guessing is bad Any thoughts?

[@HelpMeDIY]

You’re welcome. Sounds about right 🤷‍♂️

[@jeffwinne1589]

Really cool test. Kind of confusing. My 911 did the same thing so I replaced it with a Porsche motorsports problem solved.

[@HelpMeDIY]

+Jeff Winne yeah smoke doesn’t always mean it’s the AOS

[@wwilliams1358]

So initially you weren't getting any readings, then you pressed the temp button and you started to get some readings. So is the process to press the temp button after start up to get a reading? I'm not clear on the process you did.

[@HelpMeDIY]

+@wwilliams1358 I have another video on the UAOS that I do this a little more clearly I think.

[@Phil99six]

During the IMS Solution certification my AOS was replaced because it measured -6.09. I believe the range is -4 to -6 so I agree that it looks like yours is ok. But…..I’d still replace it and eliminate it as the cause of the smoke 🤷‍♂️

[@HelpMeDIY]

+Phil 996 replacing the spark plugs and ignition coils has gotten rid of the smoke 😉

[@chenzhao1071]

I'm piling up a list of things to do LOL and almost every single item you've already made a video, ha! I don't see any white smoke on start but I just did noticed a rather high-pitch noise (not very loud but I'm super sensitive to noises...) only upon deceleration today which led me to look up things and it's possibly an AOS issue. I believe mine was replaced by previous owner at ~100k on 2018. Currently at ~122k, do they fail that often?? Which area of NC are you in? If close by maybe I can borrow that special cap in exchange for some beer or coffee :D

[@HelpMeDIY]

+@chenzhao1071 they can fail pretty often! I’m in Greensboro 🍻

[@RuslanArdashev]

I’m a little confused by the conclusion - according to the measuring tool the AOS is ok but the car is clearly smoking. Does this mean the issue is elsewhere? 😎

[@HelpMeDIY]

+Ruslan Ardashev did you watch my spark plug and coil replacement video? No more smoke after that! Which proves my point that just because you have smoke does NOT mean you need to replace the AOS

[@RuslanArdashev]

Stacked cars - low key (awesome) flex

[@HelpMeDIY]

+Ruslan Ardashev 😂 🍻

[@williammcfadden6586]

Great video and very helpful! I tried this today as I have no record of my AOS ever being replaced on my 1998 2.5 Boxster. My reading seems to be bang on but when I rev the car hard, the reading on the manometer can momentarily fall to close to zero when I let the pedal off and the revs are falling. Is this normal? When revving hard the reading goes just above 6, its the return to idle where I have this momentary low reading...Thanks!

[@HelpMeDIY]

+William McFadden thanks! The pressure will definitely change under revs, but I don’t know what “normal” values are under those conditions.

[@DailyClipztt]

In my research It's normal to have higher number if you are boosting the car and the range on around 600whp cars is 4-15. Numbers go higher due to blowby gases passing by cylinder walls and pistons. The higher the number can mean looser clearances between those two and that depends of how old and used engine is. Any engine wear ...meaning those 3 piston rings get worn out and letting more blowby gases. But this is also typical right out of the back with high HP builts like cars above 600whp as they run looser clearances between pistons and cylinder walls. They need sum pumps and custom AOS as they create a lot of blowby. To go back to numbers. The best bench mark for every car would be to test it as new car then compare numbers to any older engines then you can see the wear of the engine piston rings These numbers I think exist from each cars manufacturer Hope this helps

[@RockyTopAviator]

This almost needs to be the type of tool you rent out to people for $25 shipped with the cap for your specific vehicle. While I want to do this, $70-$80 for a tool I'd use once, maybe twice, makes me shy away from it. Maybe I can take up some HVAC work or try to balance/sync carbs on a bike/car one day. Great video!

[@HelpMeDIY]

+Jacob L. Not sure I want the hassle of shipping, but anyone that lives close enough is welcome to use it free of charge.

[@RockyTopAviator]

@@HelpMeDIY Understand completely, a man of your caliber (and stable) it definitely makes sense to have that tool.

[@vGnome]

Good stuff. Does a 986.2 Boxster S use spark tubes?

[@HelpMeDIY]

+Robwith2bs Wilcox great question. Never owned one so maybe someone else can chime in.

[@nickfusco9667]

@robwith2bs Yes, it does use spark plug tubes.

[@David-hn5ix]

So what caused the smoke

[@HelpMeDIY]

+David funny you should ask… I’m about to go into the garage and start making a diagnostic video. It’s still smoking!

[@TheCompyshop]

I’m assuming the engine probably has cylinder bore score, which means it needs a rebuild

[@mgkeoh]

Nice video. I must get this bit of kit

[@HelpMeDIY]

+Michael Keohane thanks! I have a link in the description 😉

[@FlyinFreek]

Getting 12 and up at warm idle, I guess it’s toast

[@HelpMeDIY]

+@FlyinFreek sounds like it!

[@plus790]

Replaced the AOS on the 986 a couple weeks ago, even though it had been done by the previous owner just a couple years ago. Once I got into it, I notice the lower bellows weren't seated. At that point I already had the topside disconnected so I put the new one in, but I suspect the old one was still ok. I wasn't getting a ton of smoke, but the motor was damp around the secondary oil pump and burning off on the new Fabspeed exhaust. Unfortunately I had already replaced the o-ring on that oil pump over the winter too, but oh well. And now that all this is done...I just found a 987.2! I'm going to fly down south on Friday to pick it up and drive back to Chicago. S model with PDK (had a slight preference for manual), Sport Chrono Plus, and a secret under the back--a Capristo exhaust. :)

[@HelpMeDIY]

+Adam Miller exciting fly and buy! Enjoy it!

[@90sPorscheguy]

Another good video dude. Keep up the good work!

[@HelpMeDIY]

+Kyle Douthett thanks! 🍻

[@gautobras]

So why the smoke on start up?

[@HelpMeDIY]

+@gautobras bad bore scoring

[@f.l.6049]

@@HelpMeDIY did you end up rebuilding? What was the process like?

[@HelpMeDIY]

@@f.l.6049 yes, I'm in the middle of it now. There is, of course, a whole build series on my channel, do you not have notifications turned on?!?! :P

[@f.l.6049]

@@HelpMeDIY new to the world and channel, subscribed!

[@thehouckfest]

Cool video - thanks for going through this, by chance did you happen to remove a/the known good oil cap from the car while the car is running? I read/watched video that said that can be a tell tell sign. On my 987.2 CS when I do this it will "suck" the cap back down, making me think I have a failed AOS and am seeing excess crankcase vacuum. Also, see you are in NC, saying hi from SC!

[@HelpMeDIY]

+Michael Houck thanks! No I didn’t do that test, but I also hear it’s a way (obviously less accurate though) to test the pressure. Hi neighbor! 👋

[@summerli2700]

Hi friend. The video is awesome. Would you like to try our Boslla 6500K led headlight bulb? We wanna send it for you to try. I have contacted you on Ins dm. Hope to hear from you, thanks.

[@HelpMeDIY]

+Summer Li hey there! Thanks for reaching out. Unfortunately, I have done a retrofit of the headlights on my Boxster so these would no longer fit.

[@joe-serioushoward6201]

I’ve had three fail in seven years. Each time trashing my intake with oil.

[@HelpMeDIY]

+Joe-serious Howard sounds right

[@richardchandler9027]

Yup getting ready for the third replacement in 137k. On an 01 986 S. Very frustrating. It is just an over engineered PVC valve . It is open at ideal to reduce emissions by allowing crank case vapors to be burned and pulls shut at higher vacuum. If not the oil vapors are pulled in at excess. Seriously it should have been a recall. Thoughts?

[@joe-serioushoward6201]

@@richardchandler9027 I upgraded to the Ultimate AOS. Google it. It seems to be working great so far. No more AOS changes. Just change the diaphragm on top of motor because with the Ultimate AOS the diaphragm is now on top.