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This car keeps me busy. 

I wanted to change air filter and MAF's because the car is not running and shifting well. 

The procedure is easy for somebody who is handy. Biggest problem to seperate the pipe where the MAF is sitting from the pipe which is going to the turbo.

 

if the air filter is out there is enough place to work.

 

right side was a bad surprise for me. 

I had the valve cover gasket replaced some weeks ago and there is still so oil spray. I note them already . 

 

But when i had the air filter out and look down i found everything full of oil. This i guess is coming from somewhere down.

 

i seperated the MAF from the pipe and what i saw was not nice.

 

hose completely dirty with oil

MAF swimming in oil

 

i understand the air stream is from up to down. Air filter to MAF to turbo.

 

what causing so much oil in this MAF / pipe. ?

 

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Hi Thomas you asked me a few days ago how to removed this DV. see attached.

working from the underneath remove sump guard cover(s), then remove pipe numbered 1 (jubilee clip each end) and then squeeze the spring clip 1 on the small Diverter valve hose and pull the dv out of the small hose, then from the top loosen jubilee clip 1 and the pipe numbered 2 can be removed with the dv still attached. I found this was the easiest way.

Even if the DV is faulty or not is regardless, the Oil is either carry over from the turbo or more likely the PCV system (is your air/oil separator in good condition?). Porsche apparently "drain" the oil residue from the intercooler(s) bottom hose connection as routine maintenance because of oil carry over.

before getting to worried I would clean everything, ensure the dv is working, (simple test push the brass disk inside effectively opening the valve and then hold your finger tight on the vacuum nipple, it should hold the brass spring loaded diaphragm open until you release your finger and it will snap shut under spring pressure).

 

ctt engine side view.jpg

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I need to look at mine when I get home but isn't the Bypass valve plumbed in below the MAF? And the PCV (crankcase ventilation is all plumbed in after the MAF too? Isn't it? A bad Turbo seal could cause oil air to get by the bypass valve but it should end up in the airstream below the MAF I believe.

On the one side, I do pull my Intercooler lower hoses off every other year and drain the oil and spray brake cleaner up into the Intercoolers to help clean out some of the Oil. Turbo engines produce a lot more crankcase ventilation than normally aspirated since more pressure gets by the cylinders. I have catch cans on my twin-turbo Audi RS6 and plan to install a pair on the Cayenne, too many projects. I'll be home in a week and have to do a closer inspection, time to clean my Intercooler pipes again anyways.

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1 hour ago, lewisweller said:

Hi Thomas you asked me a few days ago how to removed this DV. see attached...........

 

I know Lewis . You explain me how to do it. Is your guess the DV is causing this oil mass?

 

i am not a mechanic and so my questions might sound stupid but i try to understand  the basic things on this engine.  Why a bad oil separtor which is sitting on top of the engine can be also involved in the problem i have here? 

 

Thank you for making things claer with your markings a the engine picture.

1 hour ago, lewisweller said:

ctt engine side view.jpg

 

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32 minutes ago, hahnmgh63 said:

I need to look at mine when I get home but isn't the Bypass valve plumbed in below the MAF? And the PCV (crankcase ventilation is all plumbed in after the MAF too? 

 

 

Hi Mark

like shown on the engine picture,  after the hose which is coming out of the air filter housing, the MAF is located. Next is a tube which is connected with the turbo. 

 

This hose has some kind of junction where the DV is connected to.

image.jpeg

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I hope thats not a problem with the turbo itself. Maybe i should add that some month ago the the turbo to intercooler hose was drained and got a new seal.

the car has still full boost on the gauge. 

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2 hours ago, ekstroemtj said:

 

I know Lewis . You explain me how to do it. Is your guess the DV is causing this oil mass?

 

i am not a mechanic and so my questions might sound stupid but i try to understand  the basic things on this engine.  Why a bad oil separtor which is sitting on top of the engine can be also involved in the problem i have here? 

 

Thank you for making things claer with your markings a the engine picture.

 

The DV is not the cause of the oil problem. If you have full boost then probably the DV's are not split either (although when I found a "small" tear in my DV I did still have full boost surprisingly but how accurate is our dash boost gauge?). Anyhow back to the oil, is the other side MAF also covered in oil too? If not I think this is the turbo seal problem. If the other maf is oily then pcv problem carrying over oil in the vacuum line to turbo. 

When you let off Throttle under boost the DV opens and circulate the boost around the turbo inlet and outlet causing the turbo to free wheel and prevent stalling, if their is oil in the Air flow it will invariable coat the nearby pipes and maf sensor as well. 

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13 hours ago, ekstroemtj said:

 

I know Lewis . You explain me how to do it. Is your guess the DV is causing this oil mass?

 

i am not a mechanic and so my questions might sound stupid but i try to understand  the basic things on this engine.  Why a bad oil separtor which is sitting on top of the engine can be also involved in the problem i have here? 

 

Thank you for making things claer with your markings a the engine picture.

 

Hi Thomas, I just check something and need to correct myself about the PCV issue causing both side to have oil carry over, this is not strictly true. See the elbow in the image where pipe 13 plugs directly into the oil/air separator (represented by my blue circle) and the pipe connects down to the turbo charger inlet pipe (represented by red circle) number 15.

So my point is check your oil/air separator rubber diaphragm before even thinking about dreaded turbo issues! :cursing: a new diaphragm is only $20 and 30minutes work :clapping:. Could be as simple as that to fix this issue? Fingers crossed.

CTT pcv and turbo vent lines with notations.gif

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Thanks a million for your support. 

The oil/ air seperator i wanted to check already but i found it very difficult to open the cap. I was affraid to break something. Will try it again. 

One last question about the turbo seal which you mention. Is this a part sitting inside the turbo housing?

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Shouldnt this area look a little bit more oily?

if the reason is to seperate oil and air here i was expecting more oil to see. 

Is the valve which is sitting in front of the Oil/Air seperator a part which can fail too? Any possibility to test this?! Than you

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Well I don't know really, I guess this look normal if excess oil was here it would suggest excessive blow by and that piston rings worn. So maybe a good thing! 

In the first picture it looks like metal flakes in that gudge?? 

Look at the below post might be interesting to you. 

 

 

 

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Hi Lewis

 

no that isnt metal flakes. Old dry oil i would say.

you mentioned the breather valve. I will have a look.  How possible to find out if this thing is working or not?

image.jpeg

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I just disconnected the valve to have a look inside. Indeed there are 2 orange membranes . Colour like in the AOS which i checked yesterday.  On one membrane is a part missing. Please check the picture. This means replacement?!

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I think the valve should be shut if you blow from this end shown in your picture. It does look like the membrane has perished perished is stuck partly around the seat of the valve. 

My thinking to how it works is under acceleration the turbo will suck in air via the pipe which connected to the bottom of this check valve and draw in pcv air and gasses to recycle through the engine. So effectively effectively the turbo suction opens this check valve. 

If in doubt replace it! 

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Hi Thomas. I did some work today on the Pig. Check my AOS and looks the same as yours. Also check my check valve again all ok. Cleaned my MAP sensor again and checked the passenger side recently new DV was still in good shape and replaced the vacuum pipe to the DV as a precaution. I use 4x6 mm PU tubing for all vac line replacements it dirt cheap and good stuff. 

I also checked my wastegates audibly using an compressed air source to activate the wastegate via the pipe disconnected from the N75 valve. All seem to work well no sticking, both opened at the same time at 5psi and 10psi and no leaks to be heard. 

Disconnected the battery for 30mins and then fired it up. Put my vcds on it to check for codes nothing showing. Running is rubbish as usual and worse now until adaption will smooth out some of the splutter hesitation. Fuel trims are bang on, no misfires, timing is 6degrees at idle. The new n249 change over soelonid valve on order gives me slim hope this might somehow but the faulty component but I'm not that confident. 

IMG_20160815_154907.jpg

IMG_20160815_164229.jpg

IMG_20160815_164249.jpg

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Running is bad?! Still did not found the reason? I understand from your posts its only at certain rpm. 2000, 3000, 4000 etc.

 

from where you get this PU tubing? Is there a place in the net?

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Yes still getting this stutter in acceleration. Nightmare to find the cause. 

 

The PU tubing you can buy at any good pneumatic/hydraulic parts equipment shop. 

4mm internal diameter and 6 mm outer diameter will work for our vac lines. If you need to fit it over a barbed connector or T you just warm the end with a lighter flame and push a screw driver or something of suitable size down the warmed and softened pipe end. Once about the right size, warm a final time and quickly slide it on the connector for a easy airtight fitment. Warning if you give too much heat it will melt and leak lol. Ask me how I know? 

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