Kintler11

Hello, my a6 c6 2.0tfsi is giving me an oil pressure warning when coolant temp between 40c-65c. If engine is completely warmed up there is nothing and when engine is cold there is nothing. My vacuum pump has been leaking oil and I thought it might be related to this issue, I changed the seal and the leak seems to have lessened or completely stopped though I'm not completely sure. I cleaned it and will over time look if it's still leaking. But the oil pressure warning is still showing up like before. I also seem to have somewhat of a vacuum leak as the engine is running lean 12.8% long fuel trim. I don't know if these issues are related to eachother. If anyone has any idea why the oil pressure is coming on at weird times please let me know, I'm scrambling for solutions.

sswari

Do you have any codes stored?

Kintler11

Only P0171 and P0420

sswari

come on, don't make me look this up. Copy the parts of the log.

Kintler11

Sry
P0171 - System too Lean (Bank 1)
P0420 - Catalyst System Efficiency Below Threshold Bank 1

sswari

Ok, well that is odd.
I am by no means one to just replace parts for the hell of it, but the sender on my old A6 4.2 was really cheap and very easy, I swapped in a new one and no more issues. That being said, I also was getting the low pressure pretty much every time I even started the car.
If you just let it idle till it is up to temp, will it throw the light on? Maybe you can get some more info that way?

Kintler11

If It's cold out (<32°F) it will throw the light on a minute into idling. But if its approximately over 32°F outside and then I start the car and let it idle, it works like a charm. The light doesn't come on at all if the engine is warmed up.

sswari

I don't know Dr. it hurts when I do this.
Dr. : Don't do that

Don't start it when it's cold
This is a new one to me. Could still be the sensor with a cold solder joint or something stupid. Is the one you have an Audi part or aftermarket?

Kintler11

Unfortunately not an option for me I live in a colder climate and its only warm in the summer here. Im starting to think the oil passages might be a bit clogged and when the engine warms up the oil viscosity gets low enough that it doesn't cause an issue. I dont know about the sensor and I'm gonna have to check.

sswari

Are you using the correct oil for the car and temps?