Can AOS leak oil?

[sasha055]

I've been fighting an oil leak fore more than a year.
It has all the classic symptoms of Oil filler tube leak. There's oil on top of the engine, and it leaks a couple of drops only if I push the engine from 2K RPM to redline.
If I drive slow and smooth no oil is dripping.

I changed oil filler tube 2 times and it didn't help, so last week I wrapped my oil filler tube with plastic and went for a long drive... the plastic was oily on the outside, my only other suspect is AOS
It all started about 6 month after I changed my AOS so either I screwed up installation or maybe AOS went bad that fast..

Can AOS leak oil? if yes were would it come from?

Thanks
Sasha

[sasha055]

Some more information

Car is 2000 base Boxster, 80K miles, runs perfect, no signs of AOS failure, I can pull the oil cap really easy and it runs a little rougher with the oil cap off

Thanks
Sasha

[The Radium King]

the oil filler tube assembly is actually 3 pieces - the tube that bolts to the block, the main tube between this and the bulkhead, and the bulkhead fitting. i am assuming you only replaced the main tube in the middle?

two things - when i replaced mine i still had oil weeping at the join between the main tube and the piece that bolts to the block. also, the piece that bolts to the block can also fail, especially if you get tugging on it during the replacement of the other pieces.

[sasha055]

Thanks,
I indeed replaced only the main one.
I'll check the other two.

Is there a write-up on how to access/change the other two?

Thanks
Sasha

[Eric G]

Originally Posted by sasha055

Thanks,
I indeed replaced only the main one.
I'll check the other two.

Is there a write-up on how to access/change the other two?

Thanks
Sasha

It's ugly for the first hose and how you get to it is through this write up: Pelican Technical Article: Boxster Coolant Tank Replacement - 986 / 987

So you might want to consider doing the coolant tank while your at it...if its old.

Advise is to remove the clam shell as it will give you more room to work around if your going to dig in deep. When you replaced the main tube did you remember to install the O-ring back on the end of it?

[sasha055]

I changed the part that goes from "oil cap" to "just behind AOS" and install all the rings back..

I'm still puzzled.. if any of the other two parts is broken shouldn't it be oily there? (lower near the the point of oil filler tube connecting to the engine)
In my case AOS (and the engine under it) has the most oil

Thanks
Sasha

[The Radium King]

underneath the oil fill tube is some wiring with a plastic wire protector wrap. that wrap can hold a bunch of oil; in my case that oil was splashing around after i'd replaced the oil fill tube and made me think that it was still leaking ...

[Gilles]

Hi Sasha,

A couple of months ago I discovered an oil leak between the head and the block, that looked like the part of the head gasket that covers the cam chains was failing, also I noticed as well a light seeping from the main seal...

Upon closer inspection, later I noticed that the top of the engine was also covered with oil around the AOS...

I went ahead, replaced the AOS, cleaned the top and bottom of the engine and about 2,000 miles later I can assure that the leak was from the AOS, not the gasket or the main rear seal, it was a big relief...!

BTW, I paid for the new AOS less than $100 (delivered) from Rector Porsche

.

[sasha055]

Thanks Gilles,

Did you have any signs of failing AOS? smoke at startup? oil cap impossible to take off?

The leak started about 6 month after I changed my AOS.. I know they don't last very long.. but 6 month.. that's a very little lifespan

Thanks
Sasha

[Gilles]

Originally Posted by sasha055

Thanks Gilles,

Did you have any signs of failing AOS? smoke at startup? oil cap impossible to take off?

The leak started about 6 month after I changed my AOS.. I know they don't last very long.. but 6 month.. that's a very little lifespan

Thanks
Sasha

Sasha,

No, the AOS did not have any symptoms, never smoked at startup and for that reason I never thought of removing the oil cap.

You are right about the short lifespan of your new AOS, perhaps you may want to check for a leak around the hose that connects the bottom of the AOS to the block..?

.