AOS seals and replacement

redcoupe86 · 09-02-2023, 07:49 AM

So I did a smoke check straight to the air oil separator and tons of smoke started coming out at the bottom of the AOS. I’m assuming this means the seal is bad. So what has to come off in order for the air oil separator to be removed and replaced on a turbo thanks.

I know the intake manifold will have to come off but after that what else needs to be removed?

redcoupe86 · 09-02-2023, 09:13 AM

OK for the love of God, the turbo has to come off! Jesus never had to take it off before, but it looks like a royal pain in the ass. So before I go through all that effort, I just want to be clear on how I’m thinking it’s the seal on the AOS.

First of all, I’m not getting any oil leaking on the ground. I was trying to track down a vacuum leak that I couldn’t find anywhere else I simply connected my mineral oil smoke generator to the vac line to the AOS and all of a sudden smoke started pouring out at the bottom of the oil fill tube. But I could not determine exactly where it’s coming from. I’m just assuming that it is coming from a bad seal. I do know there is some sort of leak because I was dripping mineral oil from wherever it was coming out because there was a small puddle on the ground about 2 inch diameter after I was done checking with smoke.

gb944 · 09-02-2023, 10:13 AM

Yep, it's a real pita.

I have three 15mm chinesium wrenches that I modified to each get just 1/18 th of a turn of the bolt before switching to the next wrench. Made to be installed before installing the engine in the car, not made to be wrenched on afterwards.

redcoupe86 · 09-02-2023, 10:43 AM

Which evil bolt do you speak of, so that I may make offerings to the car gods prior to beginning this self inflicted torture!?

gb944 · 09-02-2023, 12:20 PM

redcoupe86 · 09-02-2023, 01:16 PM

Thanks!

kdjones2000 · kdjones2000's Garage

Just take off the exhaust and crossover pipe, oh and then you get the joy of trying to remove that allen head bolt that holds the turbo to the crossmember. Make sure that you are VERY SOLID on that before trying to loosen it, because if you round it, it's almost impossible to get a drill in there to drill the head off.

Some people let the weight of the front of the car rest on their tool to make sure that it doesn't round out.

More fun wrenching on 951's!!

redcoupe86 · 09-03-2023, 06:21 AM

My car is on ramps to lift the front end up. My understanding is I will have to disconnect the steering rack at some point which is easy enough. However when I go to put it back will I be able to do it with the wheels on the ramps? Do the wheels need to be free hanging?

redcoupe86 · 06:40 PM

Ok. Starting to have some anxiety attics at this point. I’ve changed the clutch, pulled the cam housing, and done timing belts and balance belts but this turbo removal has me seriously thinking I may have bit off more than I can chew

So far I’ve pulled the intake (done this many times, so no biggie), and I’m trying to remove the heat shield but though I’ve removed all the bolts I can’t seem to get it out. But once I figure that out it appears there may be other shields I need to remove.

dme · dme's Garage

The biggest PITA job to replace an O-Ring...

redcoupe86 · 09-04-2023, 09:06 AM

No doubt.

So I finally go the heat shield removed, the turbo water pump out the way and the oils line off.

I saw that infamous 6mm Allen head and I figured if I couldn’t get it out this game was over. So I gave it a stab and was able to break it loose with a hardened ball end Allen. But if I switch to a stubby Allen which is the best direction to access it? From above or below. How did y’all do it.?

gb944 · 09-04-2023, 09:52 AM

Quote:

Originally Posted by redcoupe86

No doubt.

So I finally go the heat shield removed, the turbo water pump out the way and the oils line off.

I saw that infamous 6mm Allen head and I figured if I couldn’t get it out this game was over. So I gave it a stab and was able to break it loose with a hardened ball end Allen. But if I switch to a stubby Allen which is the best direction to access it? From above or below. How did y’all do it.?

From below, with a 3/8 drive short 6 mm hex socket and a long mfing extension. Stay away from the ball end sockets, they can damage the bolt head too easily, and then you are truly fubar.

redcoupe86 · 10:03 AM

I understand the 3/8 drive and hex socket but where are you connecting the extension?

Trying to understand how this works the hex bolt is more or less on the side of the block above the flange correct?

redcoupe86 · 09-04-2023, 12:37 PM

Well. I guess I got lucky. It only took me 5 min to get the 6mm and 13mm out. After the 6mm “broke loose” I just used a ratchet on the ball end Allen and it just came right out. Now getting it back in will prove to be a PIA.

Now on to the next step.

redcoupe86 · 05:31 PM

Ok. All bolts out but one. It’s the up-pipe bolt that’s has a welded stud. Looks like a pain, but what’s new everything else I’ve done so far it’s been a pain. Just gotta get a game plan.

redcoupe86 · 09-05-2023, 06:53 PM

Finally, turbo out! No on to the AOS seal.

And while I’m at it a turbo rebuild.

nize · nize's Garage

Quote:

Originally Posted by kdjones2000

Just take off the exhaust and crossover pipe, oh and then you get the joy of trying to remove that allen head bolt that holds the turbo to the crossmember. Make sure that you are VERY SOLID on that before trying to loosen it, because if you round it, it's almost impossible to get a drill in there to drill the head off.

Some people let the weight of the front of the car rest on their tool to make sure that it doesn't round out.

More fun wrenching on 951's!!

+1
what worked for me was to literally use a floor jack to "jack up" the wrench so that some of the weight of the car was on the bolt, then i whacked it with a hammer to break the bolt loose. before all this, i used plenty of PB-blaster to grease up the bolt and let it sit overnight. you do not want to mess this up and round out the allen bolt as it's near impossible to drill out.

nize · nize's Garage

Quote:

Originally Posted by redcoupe86

Finally, turbo out! No on to the AOS seal.

And while I’m at it a turbo rebuild.

this is the perfect opportunity to upgrade to a dual-ball-bearing turbo. garrett ceramic DBB turbo for the win.

https://forums.pelicanparts.com/porsche-944-turbo-turbo-s/346595-turbo-upgrade-pauer-tuning.html

redcoupe86 · 09-07-2023, 05:47 PM

I’m not going for any upgrade, just a nicely rebuilt OEM unit. I do know that I never want to have to remove the thing again!!!

redcoupe86 · 10-01-2023, 12:29 PM

Ok,rebuilt turbo from Evergreen is on. Now I just need a couple of washers for the oil line (dropped the originals down the black hole somewhere!). And attach the new oil feed line on top. Then the intake and fingers crossed we’re running again. One thing is for sure this engine was never meant to be serviced with it in the car for this stuff!