Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Advice on AOS replacement job

Recommended Posts

Hey guys, this is cross-posted on rennlist, but I thought this might be a better venue for this questions. Apologies for any overlap.

So I'm about to dig in and replace my AOS. I know it's not for the faint of heart, but I feel I can tackle it.
My question is, what else should I replace while in that deep in? I'd rather not make return visits to this part of the engine bay in the near future if it can be avoided (that place is like my in-laws). I really want to get a comprehensive parts order in before I take the car apart. I am already planning on replacing the parts for the Secondary Air Injection check valve fault as I'd like that light to go away.
Any advice is appreciated, thanks again!
Link to comment
Share on other sites

I followed the tutorial and it worked well. The hardest part for me was removal and reinstallation of the alternator. Take your time because you will have to remove, unclip, disconnect quite a few parts lines, hoses to get to the AOS using this procedure. You don't want leaks in the intake after putting it back together. Take pictures as you do the work and make sure you put the check valves in the correct orientation. There are some small diameter hard plastic lines that go into the large rubber sleeves connecting the upper intake parts. They can break or people forget to put them back in. This is not an easy or quick job, I did it over the course of a 3 day weekend.

Don't take the following list as necessary, but I replaced:

- the oil filler tube 996.107.150.61 and ~$50

- newer model oil filler cap

- newer dipstick with double o-ring seal

- the small diameter coolant lines that go to the top of the AOS

- the o-rings for the flex/ribbed lines that connect to the AOS

- the large diameter rubber sleeves that connect the upper intake sections

- new hose clamps that tighten the large rubber sleeves

- throttle body to intake tee gasket

- I replaced the oil/water heat exchanger and the orings (I noticed there was seepage of coolant when I removed the upper intake and replaced the heat exchanger due to corrosion on the mating surface)

- new serpentine belt

- air filter

- small vacuum lines going to the check valves

- replaced the fixed pulley on the alternator with the newer free-wheeling type

While in there I did the following :

-checked that the nuts holding the cables to the starter were tight

-checked for any cracked hoses

-checked for any frayed wires (especially the knock sensor cables)

-cleaned all of the oil/residue inside the upper intake

-cleaned the throttle body

-vacuumed the top of the engine to remove grass/dirt/leaves that had accumulated (make sure the lower intake runners are covered up to protecting from flying debris)

Since I had done it before, I did not include:

- water pump/thermostat replacement

- coolant reservoir replacement

- fuel filter (much easier to get to on C4's with the left upper intake removed, C2's have the fuel filter underneath the car)

  • Upvote 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.