911ct

I've just changed my AOS and wanted to share the experience. I attached my story, hopefully will help.

EricD997

Nice job! What was your mileage when AOS was changed?

911ct

38500 miles. I did not have clear cut signs of AOS failure, but I have a troublesome CEL and this is part of my plan of trying to solve it.

Edgy01

Nice write up but you refer to the use of standard tools throughout. You need to move on to metric! What's a 5/16s ??

911ct

At the beggining I used an E10 socket for the intake manifold screws. When I got stuck(at the foremost screw of the intake manifold I could not fit the E10 socket) I got one of the screws and went to a Advanced Auto Parts and found a Duralast 5/16''(not metric) ratcheting wrench that was a perfect fit for the screw. That wrench saved the whole project.

USMC_DS1

Good job 911ct and belayed thanks for this write-up... sorry I missed this earlier - looks like it came in during the x-mas holiday. Will post it on the 997 DIY sticky.

gota911

A 2.5/8 th!

utkinpol

amazing job, I heard it takes a ninja to do this if you cannot drop down gearbox.
usually AOS only gets changes when gearbox goes down due to extremely difficult access to those bolts, like you already found out.

PelicanParts.com

....lol Edgy!

But great write-up back when 911ct, good stuff.

997_rich

My AOS just failed. The symptoms were a screeching on the outside of the engine on start up. I though this screech was the idler pulley bearing. I replaced it and I didn't hear the symptom for some time.

Later when I was driving, the screech appeared again consistently. I pulled the engine compartment open but by that time I had a large rush of white smoke out the exhaust. I shut it down and got a tow home.

After some investigation (turning the engine over by hand, changing oil and filter looking for debris, disassembling the intake and finding oil on all the surfaces), i was able to diagnose. The screeching was coming from the AOS.

I pulled all the parts of the top of the engine following the write-up (great write up by the way!). I had to make a special wrench to remove the intake manifold while the engine was still in the car (see pic).

I also found that even though the starter has been working great, the starter cable was a little melted. So I replaced that in the process.

When I jacked up the car, I found that I could access some of the AOS bolts from the underside by reaching past the transmission. This may help some people.

Putting it all back together tomorrow.

997_rich

More pics of the failure.. disregard all the plastic dust.

Note that the bellows are torn. This is what causes the squealing.

iammulva

Great writeup. I didn't see a mention of how long this took. Does anyone have a guesstimate?

997_rich

It took me about 4 hours to pull everything apart but that includes investigation time, changing the oil, jacking the car, cutting and torch bending a wrench etc. I expect 3 hrs to put it all together.