Yeah, I kinda highjacked the thread. I am 2.5 hours in, AOS is ready to be unbolted, all top lines off, much easier to just break plastic connections off AOS water lines then try to undo crimp clamp with it connected.

Hardest part of the job so far was the rear intake bolt, and the 2 clamps for the rear crossover tube aimed to the front of the car. In the 1.5 inch of space I was able to hold a 7mm wrench with my fingertips and slowly undo the clamps. This is where lowering the motor would help as well as the rear bolt.

I have one lower line left as well as the two bolts, and I assume the red barbed end goes into the block, or is it another line?

I guess my next move is to undo the bolts, raise it up and undo the bottom line?

I was surprised to find the vacuum operated flapper door in the rear crossover tube.

Looks like 6 to 8 hours may be the total time. Will keep everyone posted. I have taken a lot of pictures and will do a write up of some sort.

Andy

 

the red piece sort of pushes onto (not really into ) a hole in the case... that part is wierd because I never had the "feeling" like it "went in" - took me a while to agree in my head that "in" wasnt very far at all...

there is the bellows clamp on the bottom.

access to the bolts can be had thru the drivers wheel well with wheel removed and long extentions.

Bellows clamp from the tranny side on your back, there is one route that offers a straight shot in there

I believe cutting the old bellow out is the agreed easiest aproach, then take off the clamp - be careful cutting as there are a couple wires /lines in the area

 

Okay,

Just finished. Total time about 6.5- 7 hours. About an hour was spent just cleaning parts, the inside and outside of the main intake, the t-body crossover tube and the t-body itself of all the accumulated oil residue. I would say a good independent who has done this before could do this in much less time, but they are not going to clean everything as they go.

If you have your trans out for any reason please have them fix this at the same time as it would be dumb not to do this as the part is $104 from Suncoast, my car has 76k.

Here are some observations that I have not read anywhere and may be specific to my AOS failure since mine was coolant related, but I am also assuming it was internally blocked. I am going to cut it open to see.

1. My air injection pump no longer whines like a supercharger, apparently the AOS was blocked causing it to either cavitate or be under back pressure. So if you are experiencing a loud air pump it may be the AOS. This was a total surprise.

2. If you haven't changed the plastic water coupling for the AOS near the alternator you need to. This thing disintegrates like nothing else I have ever seen. It literally turns to dust when you try to remove whats left from inside the hoses. My opinion is this part is going to cause more and more trouble by bursting as these cars get older. If I keep the car a long time I'm swapping to brass.


I did not lower the engine to gain more access, but it could end up being necessary depending on the size of your hands or available tools and no doubt it could make things easier. You have to have a lot of patience and dexterity to hold a 7mm wrench in a 1 inch size opening on the backside to undo the big clamps on the rear crossover tube.

The hardest part of this job by far is the last intake bolt. You have to make up the perfect set of 10mm socket and extension and wish it on the bolt. If you have ever seen a vet with their hand up a cows ****, that is what its like because of the distance to the bolt, the limited room to work, and the inabilty to see what you are doing.

The torque spec seems to be 7.5 ft/lbs for the intake bolts. I was able to do the first 5, I just couldn't get my 1/4 drive inch/torque wrench to fit with my available extensions, it was either too low or high to fit.

Parts needed including the AOS, 1 gallon of Peak 50/50, 1 worm clamp for lower AOS bellows, 3 small worm clamps for 2 water lines on AOS and 1 at the water coupling by the alternator, the 3 intake gaskets, the t-body oring, and that stupid plastic coupling I referred to earlier. I recommend the t-body oring as it seems to have a memory and was flat as a pancake inside the housing. The new one stuck out a bunch after installation for a good sealing surface.

Big thanks to Ivangene who helped along the way on this thread and other previous posts of his. I will try and do a full write up for everybody to enjoy.

This pic shows where mine was leaking, apparently the plastic cracked at the bottom on the round part letting the coolant slowly leak out. It had been doing this quite a long time from what I can tell.


This pic shows how you have to place the wormgear clamp on the new aos

s

 

Good pics and info, thanks. Must feel good to have that job behind you.

 

Oh yes, problem is we just got 3.5 inches of snow yesterday most we have gotten here since 1996. We don't get much snow here. So best I could do was back her out of the garage and let it warm up. Now i'm going to have to wait till the roads dry up and all the salt goes away. If any of those AOS water hoses leak I'm gonna cry.

 

I feel another thread documentary by Shark Attack on its way for AOS.... I actually soooo dont want to do this job.

 

Are you replacing your AOS due to mileage on your porsche Kyle, or are you having smoking issues at start up?

 

Kyle, be careful of the worm clamps, the rubber bellow is thin and the clamp may cut into the rubber. If you can re-use the OEM clamp.... it is way better suited for the job.

 

Kyle, going in the front door or backdoor???

I went in the back door (thru engine bay) Its an easy job, just time consuming. It wasnt nearly as bad as I thought it would be though.. you can do it......OLD MAN !!

 

Ill be going in the back door..... Still kinda Po'd at you for not telling me to do this when I had the tranny out.... Joking... Im a republican, I dont blame others for my scewups...

 

Took me 13 hours on my Tiptronic I used to have. Firggin' PITA!

I even knew every detail before going in too. Manuals are far easier from what I was told.

 

Took about 2 hours on an MK2 car last time, which was significantly easier than the MK1 set up. Did not remove transaxle (manual) or the intake manifold.

I can understand if a shop wanted to charge to remove the manifold, and I'd imagine ~4 hours to be a reasonable rate. The way we did it was from under the car, breaking one of the small coolant lines off of the old AOS for ease of removal (forward facing top line). For reference, the AOS was 90k+ miles/factory original and diaphragm not torn. I may have pictures saved somewhere if anybody is interested. Anyway, smoke issue was overfilled crankcase on that particular car.

On an MK2 with manual transmission, removing the transaxle wouldn't help in any way.