Are you sure you don't just have a leak?

 

The mechanic didn't seem to think so. I've put cardboard up under the vehicle and there is nothing on it. I don't know where it could be going...

 

Did said "mechanic" do compression checks or leakdown tests or anything?
Is your MPG or performance suffering?

 

We did a consumption test and once I brought it back to the shop he checked the crank case pressure, he said it was normal. When he drained the oil out there was roughly 4.1 quarts left. My oil gauge was empty and said to add oil, the yellow oil light came on but did not blink and said I could continue to drive but needed to add at max 1 1/2 quarts. I don't think my MPG's have been suffering. He filled it back up with Valvoline Syn Power MST 5W40 Euro, if that matters.

 

COMPRESSION test.....

 

They checked the crank case pressure, but no mention of compression test in the notes. I went in and initially asked for a compression test and was told that a consumption test needed to be done instead. I did call other VW dealership mechanics and they all wanted to start with the consumption test first as well.

 

Read the plugs

 

Hello and welcome to the forums.
Before you get sidetracked with focusing on compression testing, use the "Search Community" gray rectangle at the top center of the page and type in "Oil Consumption". Apparently it's a problem not limited to your Treg. A lot have seen/experienced it.
There has been speculation on the exact cause , from the use of low friction piston rings to a tear in the PCV diaphragm to bad valve seats.
VW says 1Qt per 1K miles is normal. I never accepted this. It's not just limited to VW as other brands have the same problem.
My '11 with (now) ~111K on it burns ~1.5 Qts every 5K miles, which is my self appointed service interval.
I've changed the valve cover with an upgraded RKX diaphragm kit and the gasket for the cover, the oil "loss" persists.
Some people get lucky to have no oil loss between services... I, like many others, am not that lucky. For now I just add some oil between services.

 

There has been speculation on the exact cause , from the use of low friction piston rings to a tear in the PCV diaphragm
to bad valve seats.

There's no speculation if you understand how engines work.
The shop already ruled out PCV .....

Crank case pressure was checked and found to be normal

The following is incorrect as it doesn't have anything to do with oil consumption. Bad valve seats
would affect compression\power\performance, not consume oil.

to bad valve seats

Lastly, how do you dismiss compression testing and follow it up with this? What method of testing do you suggest using to validate piston ring sealing if not compression\leakdown?

the use of low friction piston rings

OP, look at your exhaust (and smell it) right when you start it after it's been sitting over night.... you want to see if it only smokes initially during a cold start.... also, read #8

 

There's no speculation if you understand how engines work.
The shop already ruled out PCV .....
I didn't say it was the PCV in the OP's case, just mentioning things that could cause it. Or did you read that wrong and think I was saying it was only that?

The following is incorrect as it doesn't have anything to do with oil consumption. Bad valve seats
would affect compression\power\performance, not consume oil.

Lastly, how do you dismiss compression testing and follow it up with this? What method of testing do you suggest using to validate piston ring sealing if not compression\leakdown?
I don't discount compression testing, just suggesting to OP that there are other possible causes.


OP, look at your exhaust (and smell it) right when you start it after it's been sitting over night.... you want to see if it only smokes initially during a cold start.... also, read #8

There's no speculation if you understand how engines work.
The shop already ruled out PCV .....

didn't say it was the PCV in the OP's case, just mentioning things that could cause it. Or did you read that wrong and think I was saying it was only that?

Lastly, how do you dismiss compression testing and follow it up with this? What method of testing do you suggest using to validate piston ring sealing if not compression\leakdown?

I don't discount compression testing, just suggesting to OP that there are other possible causes.

 

1 - 11 of 11 Posts
Hi All,
I have the exact same car, same miles, same problem as Mountaingirl86. Both the dealer and local mechanic have looked and check compression, pcv, and just say it is normal for this engine. The only time I see any smoke or evidence of oil use or leak is when I go to add the 1.5 quart every 700 miles and I see a little smoke from the engine at the oil cap.
I don't have any solutions, but a couple questions:

• Is it correct that if I just continue to add oil as needed, the car should run normally for many more years? The use of oil is not degrading the engine in any other way, and it's not going to lead to some catastrophic failure of the engine?
• Every source I know says an engine swap would not be worth it, but if I did want to do one, what kind of cost would I be looking at?

 

1 - 11 of 11 Posts
Hi All,
I have the exact same car, same miles, same problem as Mountaingirl86. Both the dealer and local mechanic have looked and check compression, pcv, and just say it is normal for this engine. The only time I see any smoke or evidence of oil use or leak is when I go to add the 1.5 quart every 700 miles and I see a little smoke from the engine at the oil cap.
I don't have any solutions, but a couple questions:

• Is it correct that if I just continue to add oil as needed, the car should run normally for many more years? The use of oil is not degrading the engine in any other way, and it's not going to lead to some catastrophic failure of the engine?
• Every source I know says an engine swap would not be worth it, but if I did want to do one, what kind of cost would I be looking at?

How did they check the PCV?
What was the values of each cylinder when the did the compression test (if they gave them to you)?

 

Я бы в первую очередь посмотрел бы цилиндры эндоскопом и потом уже думал что делать. Эндоскоп сразу покажет состояние стенок цилиндров и клапана.

 

Please use English.

 

Nah, let me try to remember my Russian from gr6.... This might take a while....

 

quicker to hit google translate and probably better than your grade 6 efforts

 

truth... but I would have to care enough to do that, and I don't see that happening....

 

I have the exact same problem at 108,000. Always maintained.

 

Has anyone figured this issue out? I too have no visible oil leak. VW dealer said new motor at $12.500 for motor, $18,500 for motor/install. I find this unexceptable at 100K which is when I noticed the issue.

 

Just drive it , top the oil up when needed
It will do 3-400,000 klms easy I know I have one uses a bit of oil no logical reason why
This engine does do it , in the Audi , Passat ( I’ve seen Passats with 600000 klms on and still going strong
Time for a new motor when they go BANG
Which I Doug t will happen