yorkee

I took off the j-boot and discover something:


Where would the oil come from? Is it possible it come from the vacuum line?

The airbox and filter is clean...

Crackership

It's definitely possible for it to come from your vacuum line... I'm not totally sure, as I'm a little rusty in the world of the NA. But, IIRC, that vacuum line connects on the other end to the AOS. So, as I understand it, some oil is normal, a lot is an indication of bad AOS seals. I can't say that I'm absolutely sure, and hopefully someone with more experience will chime in, but yes, it is definitely possible for oil to come into the TB from that vacuum line.

Darwantae951

When AOS seals go bad, they leak externally, not internally. Oil in the intake is common on these cars due to how the AOS is plumbed. You should see a turbo car...

John_AZ

Do not use carburetor cleaner to clean this mess. Too harsh.

Get a can of Fuel Injection and throttle body cleaner. CRC
http://www.oreillyauto.com/site/c/de...2382&ppt=C0126

You can use it to clean your ICV/ISV .

It is the AOS seals --2 "O" rings on the black oil fill tube.
When you remove the intake to do the reseal, check and replace the vac hoses, clamps, heater control valve if you see a white deposit --it drips on the clutch and sensors +++++

GL
John

yorkee

sorry... what is AOS seals? where are they located?

pnbell

AOS = Air Oil Separator

The Oil Filler Tube is a large black plastic thing for a reason on these motors. It serves as a Air Oil Separator... Basically it takes high pressure gases that build up in the CrankCase and puts them into the intake to be burnt. Most Cars have PCV = Positive Crankcase Valve.

So the seals we're talking about are on the bottom of this large plastic filler tube, and requires removing the Intake manifold to replace.

yorkee

Thanks for the info.

I also find this.

I guess mine is not as bad but I should replace it, as well as the FPR...

ernie9468

# 17 in the parts diagram are the AOS seals.

ernie9468

yorkee__forgot but www.clarks-garage.com will come very handy when doing any maintenance on your 944.See Garage Shop Manual.

pnbell

I mean, it's not that hard to replace them. With the intake off it's a good time to replace Vacuum lines, and Clean Idle Stabilizer Valve..

But with that said: Unless your looking for work, there is no sense of urgency. This may even just be normal build up over time... You could wipe it up with a cloth, and check the intake again in a month.

Crackership

There is always the option of temporarily sealing it up with grey permatex. It'll work. And you might be able to get it done without pulling the intake... I can't remember how much room there is on an NA.

choinga

AOS should be easy to get to in a NA...it's a bit of a PITA on a turbo (with the turbo still in).

The seals are cheap and easy to replace - probably worth doing regardless. When I replaced my turbo it was pretty obvious mine weren't sealing all that well - there was a decent sized mess around one of the seals - not excessive...certainly not after 25 years worth...but enough to see they weren't working well anymore. Of course, I took it off and they were just squished down - no sponginess at all. Prior to that, I did have a little oil in my throttle body and intercooler pipes. I put a catch can on and with a new turbo/AOS seals it's as clean as it's going to get...

ernie9468

I'll go with that,use varsol & a cloth or paint brushe to clean the heavy deposite off,then like John suggested Fuel injection/throttle boby cleaner,btw I use to do mine every couple years on my ex 944.

yorkee

Thanks. I will clean it up and observe it next time I re-tension the belt .

luftpirate

I have mine torn apart now as well. Does the AOS wear out? Is there anything that should be done to service it other than replace o-rings which lead to external leaks?

Edit : Read the AOS link, that clears some things up.

This all started with a sticking throttle body, led to me pulling the fuel rail to find some of the caps on the bottom of my injectors were cracked/missing.