09 Cayman air/oil separator question

[matt1415]

So I've been noticing some smoke upon start up and I decided to have a look at the air/oil separator. Sure enough I've got oil leaking into the vacuum lines going from the separator to the intake. The part was easy to find (9A1 107 042 02) but apparently you have to buy the seals separately. My question: Is the separator itself bad or is it the gaskets that have caused the issue? I don't understand why they would sell these parts separately if they are apart of the same unit. Do I need to buy them both?

[Serg_Australia]

Hi Matt,

I had the same problem with my Cayman 2006, Australian delivery, and all I did was the following:

Note: Provided all the other areas are working fine i.e. compression, correct spark plugs, cooling system, positive crankcase ventilation.

1. Making sure the oil level is absolutely at the max. level marking
2. Fuel injector cleaner (Liqui Moly) on a (1/4 tank) full only - every 4th tank (very healthy for the engine)
3. There is also a pressure pack (spray can) for the same product which you can use in the induction system and oil separator.
4. Frequent oil changes will also help, I change my oils every 5,000 Kms.

I hope this helps.

Sergio

[matt1415]

Update: I changed the oil/air separator but still have oil being sucked into the intake through those vacuum lines. Any ideas now?

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[pdxfj]

Originally Posted by matt1415

Update: I changed the oil/air separator but still have oil being sucked into the intake through those vacuum lines. Any ideas now?

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I've been chasing the same issue on my '07. After changing the AOS twice and finally admitting defeat ,I took it to a shop. After a battery of tests they were baffled and couldn't find anything.

Just this weekend I changed the upper vent hose and cleaned out the intake (again).

So far I only had smoke on the initial startup. Hasn't been long enough yet to determine if the new vent line helped or not. I can say it "felt" different installing the new line onto the AOS and plenum, vs the old (and likely original) one.

Just for the record I was only getting oil into the drives side part of the hose. Passengers side was dry.

I will continue to drive the car this week and likely do an AX day on Thursday. Fingers crossed no more damn smoke. Will post up here with my results if you like.

[matt1415]

Originally Posted by pdxfj

I've been chasing the same issue on my '07. After changing the AOS twice and finally admitting defeat ,I took it to a shop. After a battery of tests they were baffled and couldn't find anything.

Just this weekend I changed the upper vent hose and cleaned out the intake (again).

So far I only had smoke on the initial startup. Hasn't been long enough yet to determine if the new vent line helped or not. I can say it "felt" different installing the new line onto the AOS and plenum, vs the old (and likely original) one.

Just for the record I was only getting oil into the drives side part of the hose. Passengers side was dry.

I will continue to drive the car this week and likely do an AX day on Thursday. Fingers crossed no more damn smoke. Will post up here with my results if you like.

Ya I was pretty pissed off after spending $200 on a new separator only to find out that wasn't the problem. Our engines are a bit different but all Caymans seem to be prone to this issue. I'm curious what kind of air filter are you using? I have a K&N in there right now and I'm wondering if the increased air flow is causing oil to be sucked out from the oil sep. Just a theory though probably not relevant

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[pdxfj]

I'm using a stock Mann filter. Brand new, with about 2k miles on it now. The shop did compression tests, bore scoped the cylinders and used a manometer to measure vacuum pressure and everything was well within spec. No signs of any bore scoring. They said the engine and car are in great shape for the age and mileage (97k).

I expect a puff of smoke every now and then since it seems to be rather normal with flat engines. Not the fog that lasts 15-20 seconds before clearing up. If all you did was change the AOS and not clean out the residual oil, it can take a while for it to clear up. The upper vent hose can hold a lot of oil. I took the plenum off and the other crossover tube off and wiped everything clean, including the intake on both sides.

This is what I'm finding on the drives side of the plenum where the AOS vent line attaches. Only on the drivers side. Passenger side is dry.

[matt1415]

Originally Posted by pdxfj

I'm using a stock Mann filter. Brand new, with about 2k miles on it now. The shop did compression tests, bore scoped the cylinders and used a manometer to measure vacuum pressure and everything was well within spec. No signs of any bore scoring. They said the engine and car are in great shape for the age and mileage (97k).



I expect a puff of smoke every now and then since it seems to be rather normal with flat engines. Not the fog that lasts 15-20 seconds before clearing up. If all you did was change the AOS and not clean out the residual oil, it can take a while for it to clear up. The upper vent hose can hold a lot of oil. I took the plenum off and the other crossover tube off and wiped everything clean, including the intake on both sides.



This is what I'm finding on the drives side of the plenum where the AOS vent line attaches. Only on the drivers side. Passenger side is dry.

I replaced the vacuum lines and cleaned out the throttle body and plenum. After a day of driving I noticed the smoke again on cold startup. New vacuum lines were glazed with oil just like the old. I'm going to look into designing an oil catch can setup that I can put in line with the oil separator. I just can't have oil going into my intake like this.


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[pdxfj]

Well I can say changing the upper vent hose made no difference. A friend suggested I take it to a shop just down the road from where I took my car originally. From what he says, the shop he recommended are experts in the water cooled engines. The place I took it is a very good shop, but they have shifted more to the air cooled crowd.

There has to be a (hopefully simple) solution for this issue. I'm not sure if oil is being sucked though the AOS, or pushed up.

What brand and weight of oil are you running?

[matt1415]

Originally Posted by pdxfj

Well I can say changing the upper vent hose made no difference. A friend suggested I take it to a shop just down the road from where I took my car originally. From what he says, the shop he recommended are experts in the water cooled engines. The place I took it is a very good shop, but they have shifted more to the air cooled crowd.

There has to be a (hopefully simple) solution for this issue. I'm not sure if oil is being sucked though the AOS, or pushed up.

What brand and weight of oil are you running?

Total quartz 9000 0W40

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[cnavarro]

Originally Posted by matt1415

Total quartz 9000 0W40

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Where do you normally set your oil level?

[matt1415]

Originally Posted by cnavarro

Where do you normally set your oil level?

7.5 litres (the max)


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[cnavarro]

Originally Posted by matt1415

7.5 litres (the max)


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That's not helping your problem. I've seen this happen before when people overfill the engines. It creates additional windage that puts a higher load on the AOS. I'd recommend filling to one bar above the minimum. That will help significantly.

[matt1415]

Originally Posted by cnavarro

That's not helping your problem. I've seen this happen before when people overfill the engines. It creates additional windage that puts a higher load on the AOS. I'd recommend filling to one bar above the minimum. That will help significantly.

I hope you mean one bar bellow the maximum. Will that not set off the low oil warning if it's that low? I don't know how the computer measures the oil in regards to how much is really in the engine vs what it's telling you.


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[cnavarro]

Originally Posted by matt1415

I hope you mean one bar bellow the maximum. Will that not set off the low oil warning if it's that low? I don't know how the computer measures the oil in regards to how much is really in the engine vs what it's telling you.


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No, I did mean to say one bar above minimum. That is how we set the oil level even on race cars. If it is above the minimum, there is enough in there.