Originally Posted by 996_C4S

Question re: AOS replacement for my '03 C4S. Thinking of getting the Motorsports AOS vs the stock part; this is my second AOS failure (two diff 996's) and I'd like it to be my last. Any experiences to share? Is it worth the extra dough?

Originally Posted by manansal

hello everybody,

i just did this aos replacement. i thought everything went fine, but when we went to restart car we had a backfire and the car won't stay running.

any ideas?

i am thinking i might have a leak somewhere. maybe from the cross tube behind the throttle body, or the throttle body itself. does these sounds like the correct symptoms?

thanks!

Originally Posted by perryinva

Please, STILL can't find the answer to the question : On the 3.6L MKII engine, is there a bellows pipe that needs to be replaced? As stated, when you order the part number 996-107-175-50 as shown in the PET for part, "10", the bellows, you get a 90 degree bent oil hose pipe, instead. Pelican shows the part number for the bellows as 996-107-237-52, but lists it as '99 through '01 only. Yet the AOS is the same. Anyone that has done this, can you shed some light, please?!

Originally Posted by perryinva

So when you took off oyur old AOS, there was no bellows installed?

Originally Posted by 450knotOffice

Now that the engine has been lowered and the throttle body is off and some basic connections are disconnected, it's time to dig in deeper.

The first task should be to loosen all eight of the big hose clamps connecting the plenums to the intake manifolds. I used a 7mm socket with extension to make quick work of that job. Now leave it. Don't try to remove the plenums yet, you will likely just waste a lot of time trying.

Next, loosen and remove ALL of the intake manifold bolts. Trust me on this (I learned through trial and error throughout this job) - if you remove the manifold bolts first, you'll then be able to move the manifold outboard a bit to enable easy removal of the the two plenums.

The hardest job yet is finally upon you, your poor arms, and your patience. Trying to get the 10mm intake manifold bolts off is not easy - especially the last one in the very front (my favorite expression always began with an F. My neighbors probably think I'm crazy now - muttering to myself while hugging the engine of my beloved 996 ). The bolts aren't tight; they're just hard to get to. Actually, the rear five aren't too bad. It's the previously mentioned last one. Number six. Here's what I finally figured out: Do NOT try to come at it at any angle with a swivel socket. It won't happen. If you use a 1/4" drive socket extension about the height of the manifold itself - maybe 7 or 8 inches, and leave the wrench off for the time being, you can come around the left side with your left arm and then, as you feel your way past the edge of the manifold, come straight down - STRAIGHT DOWN - and feel for the bolt head down there. If you've gotten your socket near to where it needs to be, it should slip right onto the bolt head with only a little wiggling to find it. I HIGHLY recommend that you go in bare handed at first - with no wrench. Try to "learn" the layout of the manifold down there with your fingers, Find the bolt head. Feel where it is in relation to other landmarks. Get familiar with it. Then, when you're comfortable finding it every time with your left hand (basically you index finger only), try it with the socket and extension. You should be able to find the bolt head if you come absolutely straight down on it. It's a tight fit in there, but don't give up. Once you're on it, bring the wrench in, carefully attach it to the extension and slowly loosen the bolt.

Make sure you have a magnetic pickup stick. You WILL drop sockets and bolts onto the case.

Now you can see the AOS at the front left. As my Porsche mechanic friend recommended to me, don't pull any water hoses off of it just yet. Pull off the big hose on the right (with that funny connector again) and that's all.

Now, head down underneath the car with a light and get into position to see the AOS from below. You'll see the bellows and it's clamps. My Porsche mechanic friend told me to just take some pliers, squeeze the clamp, and pull it (the clamp) up and off the metal tube that the bellows attaches to. It's a bit ungainly and will deform the hell out of the rubber bellows, but no worries - you have a new one. Now, take your trusty 10mm 1/4" drive socket and about 15 inches of extensions and come in from the side and remove the two bolts that hold the AOS onto the case. Get a screwdriver or something similar and start wedging it outboard. Once it's clear of the case, climb back topside, grab the AOS and pull it up and back toward the rear. Once you have it in front of you, it's a simple matter to pull off the two water hoses, but be aware that you will spill a few ounces of coolant, so have a small container ready for the overflow.

Woohoo!! The AOS is out!