Diagnose my oil Leak

infrasilver · 4 Mar 2018

From memory I think a single 10mm bolt holds the connector to the head and there is a gasket/O ring under it, the tube that goes to it from the AOS is pinch/squeeze fit onto it and unless you can get your hand onto it easily you will never get it off and is an O ring to seal it.

You may need to remove quite a bit of kit surrounding it, loads of labour and pennies for the parts.

Kingb4 · 29 Mar 2018

I thought I would check the AOS itself, before I started to sort the weeping AOS breather pipe. I looked in the inlet and could see a slight oil misting. Then tried removing the oil-filler cap, whilst it was running. It would come off, but I could definitely feel suction.

Apparently suction and some oil (but not defined how much, as apparently 'some' is normal) in the inlet are signs of possible AOS failure, but as they are 'subjective', I decided to do a definitive test.

To definitively check the AOS - I built a DIY Slack Tube Manometer (I have seen a few of these on various forums). I warmed up the engine, then did the tests with revs less than 1000rpm and AC off. Apparently 5 inches of water is the expected vacuum, with 6 inches plus as 'suspicious' and 7 inches as confirmed AOS failure.
Thankfully, mine came out as exactly on 5 inches. Which teaches me that the ear and feeling by hand definitely cant tell you how much vacuum is being pulled.

So now I will focus on sorting the breather pipe. Which will hopefully just be the O-rings, but looks a pig to get to........

deMort · 29 Mar 2018

And this is why i read here every night .. the ingenuity of what you guys come up with is amazeing .

:bow:

There is no easy way of figuring an AOS failure .. they can block or they can pull up oil and dump it in the inlet mainifold .

987 yesterday .. we had to use 2 hands to get the oil cap off .. obvioulsy blocked .

Fitted a new AOS and if left over night it smokes enough to trigger the fire alarms .

Lots of checking and it seems like the new AOS might be faulty .

Your test .. excellent .

Any smoke on startup should clear in 15 - 20 seconds imho .. if not there is a fault or the beginning of a fault .

Kingb4 · 29 Mar 2018

Thanks Demort - I cant take the credit. I saw (and copied) the idea on another Porsche forum....the measurement of whats passes/fails is apparently based on lost or research/testing by Jake Raby in the US.

Strangely, in my mind, I had already decided the AOS must be bad, so was already gearing up to drop the engine.....I have to admit that whilst I am grateful not to have to do the AOS replacement, there was a small part of my that was excited to drop the engine out.

wasz · 29 Mar 2018

There was a thread on rennlist where jake raby said loads (1/3?) of AOS he buys - genuine parts - are faulty. He has made a rig to test them before fitting.

asterix_the_gaul · 29 Mar 2018

Wow that's a frightening statistic! How do you go about demanding a refund of Porsche for a duff aos? if they have a defect rate of 30% the supplier would be in trouble surely

Kingb4 · 30 Mar 2018

I read a similar stat somewhere about AOS failure rates. There were several people complaining their new AOS had only lasted 3-6 months.....One was offered a new AOS, but understandably the owner was more concerned with who would pay for the labour needed to switch out the AOS again.....

Palladium · 30 Mar 2018

do you have a record of the repair process, like pictures. video?

just to rule out anything not being put back correctly, it can happen.

Kingb4 · 30 Mar 2018

Sorry Palladium - you have lost me? (doesnt take much)

Palladium · 30 Mar 2018

Kingb4 said:
Sorry Palladium - you have lost me? (doesnt take much)

you said you had an oil leak, you weren't sure of its origin, you said you had repairs to the ims and there was suggestion that it could have been due to the work you had done, of course just a suggestion,

i asked if during the major work of ims upgrade, any record, either pictorial or video had been undertaken, for the protection of both garage and customer, to show its correct fitting, or any other procedure you had done, i mean we are talking big money,

i fix things for people, i often take before,during, and after shots for peace of mind. :thumb:

Kingb4 · 30 Mar 2018

Ah, I understand. Sorry, thought you were commenting on the AOS failure rate.

I only have the receipt for the IMS Seal (done with the clutch) - the previous owner had it done. Although I did call Box911 when I was buying the car and they looked up the work record and confirmed what had been done.

Its barely leaking at the bottom of the engine (where the traditional IMS leak appears) - its damp there, no dripping. I have cleaned it off and will see how I get on...... I will address the AOS breather pipe leak, as that seems to be spreading a thin film of oil across the engine bay. Clearly a little oil goes a long way, as the level on the dipstick and digital display isnt dropping (admittedly I've only done a few hundred miles in it since I bought it).

Diagnose my oil Leak

infrasilver

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Kingb4

Montreal

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deMort

Monaco

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wasz

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asterix_the_gaul

Barcelona

Kingb4

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Indianapolis

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Palladium

Indianapolis

Kingb4

Montreal

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