rsabeebe

Just a bit of background, if you haven't seen some of my other threads about my coolant loss, overheating, seeping cam tower gasket, etc. in the past. basically, i had coolant loss from the reservoir on a regular basis, overheating symptoms, a cam tower gasket that was leaking onto the headers, a leaking ps rack and various other small issues. so the slippery slope began, the teardown commenced and pretty much everything accessible was replaced, unless it showed to be in great shape. i had assumed the seals on the oil filter housing had let go and were allowing for a mild mixture, but i never saw any oil in my coolant. when i pulled the water pump, there seemed to be a minimal milkshake residue in there. when i pulled the lines to the oil cooler, all coolant and oil came out separately and clean. so, i seemed to still be chasing my coolant loss issue. all new seals/gaskets were replaced on the housing, cam tower, with water pump and all hoses to go.

i'm still piecing everything back together and, even though i had the AOS hoses and seals, i considered skipping that procedure just based on how much of a pita the removal looked of the AOS. in the end, i decided i was going to at least replacement the small, upper elbow hose - at the top of the AOS - and check to see how things looked. i'm guessing now, based on the pics below, i have bad seals on the AOS and need to pull everything to reseal it. am i correct, based on what the pics show, that i more than likely have leaking seals on the AOS?

if so, i'd appreciate any hints on how to perform this removal/install with the least frustration and/or need for mass quantities of alcohol. the black bracket in front of and curving towards the AOS - does that have to come out and is there a 3rd bolt at the bottom? i assume it won't slide out with just the top 2 bolts removed - that would be way too easy for a 951. can the AOS actually be pulled with the brake booster heat shield in place? my car was up on jacks for quite a while, but it's back on the ground now - soon to go back up - but i can't get a good look-see underneath right now.

when i pull the AOS, can this be cleaned similar to say the remote oil cooler? can it be flushed of gunk and reused or am i looking at a new AOS? i would appreciate any help any of you are willing to give. i know many have gone through this and your insight would be extremely welcomed.

thanks very much.

Grandpa#3

Nothing is easy when working on a 951. Maybe the link below might help. Sometimes a PO left out the bottom bolt to make it easier to change out the 3 AOS seal. The heat shields will have to be removed.

https://rennlist.com/forums/944-turb...951+AOS+remove

Cheers,
Larry

Techno Duck

The AOS looks like it has the typical collection of grime for its age, probably from leaky and sweating hoses. The only way to tell if its leaking is from under the car, you will get oil dripping down the side of the oil pan. I would replace all the hoses associated with the AOS while the intake is off.

These cars are old enough that in my opinion if the seals are still original then its probably leaking. Leaking o-rings tend to introduce more oil into your intake track from blow by.

It has been a long time since i have done this job, but i seem to remember the down pipe had to come off in order to get the AOS out. The heat shield is held on by 2 bolts which also sandwich the black curved intake manifold support and the downpipe support. The bolt that supports the downpipe is one of those "troublesome ones" often left off. As far as i remember, the heatshield and intake manifold bracket are sandwiched against that downpipe support and cant be removed.. i could be mistaken though.

The top of the AOS is actually not usually meant to be taken apart, the top cap where the hose connects has to be pried off, also their is an o-ring that should probably be replaced on said cap. I suppose you can just spray liberal amounts of brake cleaner in it and let it run out.. there is nothing actually inside of the AOS, its just an empty chamber.

rsabeebe

thanks for the replies, guys. i have to agree with you, grandpa, nothing on this engine is 'easy'. the layering and captive pieces from something else just drive you nuts. it makes the A -> B -> C -> D scenario so easy to get out of hand.

based on what you have said, techno, i'll probably leave things as is, since i have no desire to remove the original downpipe with nuts that will be nearly impossible to get off. it's bad enough i'm hoping to put on a test pipe and need to get the 3 bolts at the bottom downpipe connection. if the build up in the AOS doesn't seem problematic and considered normal, i'll clean out the openings and just piece it back together for more. i also have little desire to get those heat shields out with the motor in either. that crap is just too packed in there and i'm losing my patience already.

thanks again. i really appreciate the information.

kev951

remove turbo.. step 1

zerMATT951

Sounds like you're headed down the same road I did a few years ago when I finally tackled a blown head gasket. I decided to replace all hoses, o-rings, seals, and gaskets on the entire motor, stopping short of pulling the pan because it wasn't leaking, and I didn't want to pull the engine out of the car.

You might check out my old thread when you've got time... lots of pics - mostly of re-assembly after I tore everything off and performed a proper cleaning.

https://rennlist.com/forums/944-turb...ly-thread.html

rsabeebe

if i remove it, i'm upgrading it and that's not in the budget at the moment.

rsabeebe

great thread, content and pics. love the level of detail/finish on everything. i'm sure i might find some of those pics helpful during assembly. you certainly slid down the slope a bit farther than i did, but i'm sure this is what 95% of turbo owners run into when they top off the coolant.

thanks for the heads up on your thread. i hope to post some pics and finally an 'it's alive! it's alive!' post as you did. hopefully with a bit less drama afterwards. i really need to wrap this up, the wife is getting tired of parking outside while the 3 porsches are inside.

kent426

I did the Lyndsey Racing AOS bypass. Removing the AOS is not easy, it will take about 8 hrs. You don't need to pull the turbo. The heat shield is the biggest pain portion.

Thom

I would leave it until upgrading the turbo.

fejjj

Did mine when we put my Turbo DP/3" exhaust in.

I had been chasing an oil consumption problem (1qt/600 miles) and after changing the seals and hoses my consumption was less than 1/2 qt in 600 miles.����

ehall

lol YEP!