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You may want to go to Skips threads on the UAOS to understand what happens when the oem AOS fails. You don't want this to happen. People don't take the repercussions seriously enough. Best case you get a little smoke. Worst case you get intermix and/or hydralock. The oem aos is a brittle piece of plastic and rubber that will fail in many places. Especially if its as old as the car.
Do yourself a favor, get the car into the best porsche specialist you can find to make sure you haven't damaged the car, and if not, get yourself the UAOS track version. You won't loose any sleep again. While you are in there, replace the water pump with another oem water pump. That was you will mitigate two catastrophic failure points.
Yes, the factory system is designed to have 4-6 "inches of water" vacuum on the crankcase., when it fails you can have as much as 400 "inches of water" vacuum ( 29 inches of mercury) ... that's 100x the vacuum the system is designed to handle...or anything in-between..
Glenn has been writing a paper to inform on all the advantages/benefits of the UAOS System. I never mention them all in a single post because there are so many, like I didn't mention the warning system or the fact that all coolant lines are no longer used due to the relocation of the low pressure/high velocity zone...I spent a year designing and developing the UAOS System..
Glenn has been writing a paper to inform on all the advantages/benefits of the UAOS System. I never mention them all in a single post because there are so many, like I didn't mention the warning system or the fact that all coolant lines are no longer used due to the relocation of the low pressure/high velocity zone...I spent a year designing and developing the UAOS System..
Yeah, i am by no means an expert nor plan to be. Just a happy customer that paid full price for the UAOS track version that wants to help Skip to collect all of his thoughts and information on the UAOS and condense into a simple summary. Similar to what Pete did with his explanation on UAOS instalation. UAOS failure is a topic with complex implications that most gloss over. After experiencing 2 factory aos failures and a motorsports aos failure I appreciate what Skip has designed.
Yeah, i am by no means an expert nor plan to be. Just a happy customer that paid full price for the UAOS track version that wants to help Skip to collect all of his thoughts and information on the UAOS and condense into a simple summary. Similar to what Pete did with his explanation on UAOS instalation. UAOS failure is a topic with complex implications that most gloss over. After experiencing 2 factory aos failures and a motorsports aos failure I appreciate what Skip has designed.
Yea, that's another Myth that is hard to bust, many believe the Motorsport AOS is leaps and bounds better than the Factory AOS when the only thing it does different is it holds 1/4 quart more oil and lowers your oil level by 1/2 quart when it's full and can't handle any more...
Took me an hour to get it out. Left bank 1 manifold on, expansion tank in, alternator in, and didn’t touch motor mounts. Would've taken less had I not unbolted the AOS prior to getting the bottom hose off (not the accordion, the one to the right).
So much crap going around about this thing. About to make a thread about how to change this in less than an hour. Installing it is going to be easier than taking it out.
Couple of things:
1 - I still stand true that my AOS was fine and that the initial vacuum leak was caused by a failing / ripped / old bellows tube. It was not a faulty aos that caused the rip in the tube. The fact that the tube was still “there” and seated (albeit with a small tear) is the reason the aos never smoked / failed completely (it would've eventually obviously). The reason the aos started to fail in the first place is because the bellows tube was ripped on the backside. The reason it became dislodged on my go-around is because I used hose clamps and probably over-tightened it. When it dislodged, the aos failed completely and at a more aggressive rate, showing the smoke and loud squeal.
2 - the "rubber inside" talked about was 100% fine prior to me ripping it up to take it out and take a picture of it. No "rips" or whatever people say happen to it were present. The spring was functioning just fine. It’s a rubber piece covering a circular piece of plastic suspended by a spring.
3 - my aos and car would probably still be fine had I not re-installed a bellows tube with worm-style hose clamps. Should've just unbolted the aos from the block to give me more wiggle room and bought the finger-safety style snap clamps that were on the car originally.
4 - the reason i found a small amount of oil in my intake manifolds originally (when I made that other thread about the car wash a few weeks ago) is because the bellows tube was ripped and preventing the aos from working at its full capacity. I still don't believe there was anything inherently wrong with the aos as-is (before I stabbed with a flathead, obviously).
My take on this is that:
The bellows tube malfunctioning / ripping will cause the AOS to malfunction. It is not the other way around. I don't see why an original AOS wouldn't last well past 200,000 miles. There have been many people state that they see original aos's last for a very long time. My proof for this is having an original ripped bellows tube cause a vacuum leak, but it was still seated properly and had a small tear so the aos never showed smoking/aggressive symptoms. My aos never "failed" during this, it was just on its way. It was only when I changed the bellows tube with hose clamps that the bellows tube slipped completely off the north port and that’s when sh*t hit the fan. The car was running great for about 20-ish miles there and then the squeal came on very aggressively out of nowhere. My guess is the hose slipped due to me using regular worm-style hose clamps.
So replace the bellows tube, or put your finger up behind it to feel for rips before you change your AOS, and don't use hose clamps like I did. Use the snap clamps with the finger safety so you can get it on without removing the aos. And unbolt the aos so you can get the tube on easier, don't try to do it with the aos bolted to the block.
F*ck this thing and the internet. Just break the coolant tabs off the aos and remove the lines that way. Saves 30 minutes. You're replacing them with a new aos anyway........ and use hose clamps on the coolant lines. Position them when reinstalling so you can get a socket on them. Reach under the manifold with your right arm and over the bank 1 side with your left arm like shown.
^ this pic is supposed to show how you get your right hand behind the manifold. Look under the manifold to get eyes on the two hoses while you finagle them out.
this rubber piece was fine before I ripped it up to take it out. Looked brand new in there.
^ murdered it with a flathead.
spring that was suspending the circular plastic piece.
Reinstalled everything. Smoked out the entire city of hermosa beach for about 20 minutes before it went away.
I’m getting a faint whistle now. There’s another thread I found where a guy replaced his AOS and had the same thing - even took it to a dealership. I have re-checked everything a thousand times. Everything is tight.
is it possible that a brand new AOS gives off a faint whistle for a bit? I’m driving it and it seems fine. ICV had to re-learn the idle but overall idles great and pulls hard now.
Edit: stopped whistling just now for the first time. Only thing I did was Jack it up one more time and have a look. Wiped away some excess oil that had dripped from before, but no leaks present. I pushed in on the hose one more time above the variocam connection but it didn’t move. Dunno. Seems to be running fine. No knocks or smoke anymore. Fingers crossed.
10-27-2023, 06:03 PM
