Dragonfly253

Hello.

My A6 (which I enjoy immensely!) started blowing out a fairly large puff of smoke at start up (whitish with a little blueish). It drives fine. I drove it hard (awesome!), parked, and then the smoke was continuous, minimum oil light came on.

I parked it overnight, started same puff of smoke, not continuous this time. I checked oil it's at level.
Here's what I know and what I've tried:

1. No water in oil. Although it seems to be consuming more. It's black looks normal.
2. No oil in water. Level is consistent.
3. My ODBC reader (BlueDriver) reads:
   1. P2279 - Status STORED - Leak in air intake system (8825)
   2. P0068 - Status STORED - MAP/MAF Throttle Position Correlation (104)
4. I cannot take the oil cap off while engine is running (from a post on troubleshooting PCV). Comes off when engine stopped.

I have a good mechanic (Audi only guy), appointment scheduled. This is a post for my education, I like to 'know' my machines. I'm happy to share mechanics info in a PM for anyone in Springfield, MA area.

I realize everyone's 'crystal ball' only goes so far, I appreciate any feedback on what it might be, what it might cost, similar experience, troubleshooting tips, questions...

Once resolved, I will post solution for the community.

kelisko

If you have the 3.2 FSI, start with checking the PCV valve yourself for proper connection. It's at the back of the intake manifold. If it's disconnected it could trigger the symptoms of a failed PCV valve. Check the connection to the back of the upper intake and the connection to the breather hose down below. I replaced mine by preventive maintenance but I don't think it was necessary. The PCV valve rarely fails on the 3.2 because the pressure inside the engine is not as high as with the 3.0 TFSI. This is what it looks like:


If you have the 3.0 TFSI, the PCV valve is integrated into the oil separator and getting to it is a lot more complicated as removal of the supercharger, lower intake, fuel pipes and top coolant hose would be necessary. Here is a link to a playlist of videos showing how I replaced the oil separator (+ PCV valve) on my A7 3.0 TFSI: https://www.youtube.com/playlist?lis...zxScBXRXBZV5-N

Dragonfly253

I've seen your videos, nice work.

I was expecting an American style PCV, you know, attached to valve cover, pull it out, put new one in....and then I saw your video. Hands up, steps away from the tool kit. It goes into the mechanic on Tuesday. I will update this post with final diagnosis, cost, etc.

I forgot to mention I get the 'minimum oil level' warning, oil is at level? Another clue?

What is the function of the 'oil separator'? I've seen blogs where people describe this as getting filled with oil.

Thanks again for the feedback, enjoy the day!

Dragonfly253

Correction:
"I forgot to mention I get the 'minimum oil level' warning, oil is at level? Another clue?"

No question. ".... oil is at level."

kelisko

If you get the minimum oil level warning whereas oil is at level, you may need to check the connector to your oil level sensor or replace the sensor if it's not a loose connector. It is installed on the oil pan.

Some gases escape through the piston edges (rings) during combustion. They are called blow-by gases. Blow-by gases are vapors containing oil, air, debris, carbon, water, unburnt fuel. These vapors end up floating inside the engine and would cause oil coking onto engine parts that do not get fuel or oil lubrication, causing nasty carbon deposits. They would also settle down into the oil when the engine cools off contaminating it highly. To prevent this, the oil is separated from the mixture by the oil separator and routed back into the crankcase. The rest of the mixture is reinjected into the air intake system to be re-burnt. So the oil separator helps the engine keep its oil clean and prevents oil coking or carbon buildup.

Sallad

Its actually not a hard job at all. Its just a longer process of removing things, one by one. Nothing too hard to remove or the need of special tools.

I did it last summer.

Dragonfly253

Thanks for the reply!

Kelisko's video is excellent, if I had the time, patience and garage (I'm in Massachusetts, USA) I might do it.

Another thing, this diagnosis is currently a 'best guess', the mechanic will give a true reason for the trouble. Which I will post for the group, I will also ask him how he determined root cause and share that as well.

Dragonfly253

It was PCV, here's details:

Cause: Started cold 11-30-22 to record any misfires and inspect for blue smoke. Noted a good amount of soot in tailpipes. Found 2 faults for Leak in Air Intake System Intermittent and MAP/MAF <-> Throttle Position Correlation Intermittent. Tried to remove the oil cap while running and the cap is hard to turn. Found 10inches of vacuum on the crank case.

Correction: Suspect the engine breather/PCV has failed allowing full vacuum on crank case. Recommend replacing the Breather/PCV and retesting.

3.2L V6 (BKH) GAS Breather/PCV replacement
$1,530.96
Intake manifold removed+reinstalled
Noise dampening pan removed+reinstalled
Coolant drained+filled
Coolant pipe removed+reinstalled
Fuel distributor rail removed+reinstalled
Breather/PCV replacement
Labor
2.5 hours
$300.00
Oil breather/PCV
Part
$313.33
Breather vent hose
Part
$280.00
Repair Kit
Part (I asked, O ring kit for fuel rails)
$68.33
6 items
Part #: 06E998907G 06E 998 907 G
Note: Updated 11/17/22
$409.98
Coolant pipe under intake
Part
$126.67
NEW STYLE PRE MIXED AUDI COOLANT
Part
$28.57

The minimum oil light is due to hood latch which they jumped, recommend replacing to resolve.

Sallad

Holy CRAP!!

Its amazing how much money you can save just by doing it yourself

A6 4.2 Vier

The labor was only $300, the rest of the cost was in parts.
They installed the overpriced injector o-ring kits, I would only expect to see this if they pulled and cleaned the injectors.