Hi, I have a audi a3 8v 2014, 1.8 tfsi.
I had a warning message appear saying low oil, usually i get this every 6-8 months but I know these cars are very prone to burning oil, but this time, it appeared after a month of changing the oil, and it seems to be around the oil cap.
I cleaned the oil cap and around it with some brake cleaner and took it for two drives, first time I saw no leak, the second drive was a bit longer and on the motorway and I saw oil around the cap and no where else. I decided to buy a new oil cap but no luck, still same issue.
I smoke tested it and saw nothing, maybe it's too sunny but even then I heard no hissing and saw no smoke no matter the angle I looked. I also opened the cap and it was pressured with the smoke. I have a feeling it's when I'm driving at high speeds that pressure builds and pushes it out the cap?
I think that would point at the pcv but I changed that in oct 2025 and it hasn't been a problem until now, or atleast not that I noticed? As there hasn't been a warning for low oil since changing the pcv.
I can't recall why I changed it but one of the spark plug holes were leaking so I took the rocker cover off to reseal and it fixed the issue and decided to change the pcv also. I got it from Febi on Ebay themselves, I'm sure it was to do with something I read on an audi forum and thought whilst I'm here why not..
My next test will be using dye to track where it's coming from but has anyone got an idea what it could be? I've also read that aftermarket pcvs fail, but I'm sure the car would throw a warning? Or would I have to use PETKA to check as it would be hidden? Also is there a test for pcv on PETKA to verify if its blocked or got issues? If so could someone share a screenshot/ instruftioms of what I need to do to test it please?
Also i noticed that one area (right side) of the pcv is oil stained already but the other (left side) isn't, not sure if this is useful information.
Also sorry for the long message, trying to be as detailed as possible. I've attached some images
I had a warning message appear saying low oil, usually i get this every 6-8 months but I know these cars are very prone to burning oil, but this time, it appeared after a month of changing the oil, and it seems to be around the oil cap.
I cleaned the oil cap and around it with some brake cleaner and took it for two drives, first time I saw no leak, the second drive was a bit longer and on the motorway and I saw oil around the cap and no where else. I decided to buy a new oil cap but no luck, still same issue.
I smoke tested it and saw nothing, maybe it's too sunny but even then I heard no hissing and saw no smoke no matter the angle I looked. I also opened the cap and it was pressured with the smoke. I have a feeling it's when I'm driving at high speeds that pressure builds and pushes it out the cap?
I think that would point at the pcv but I changed that in oct 2025 and it hasn't been a problem until now, or atleast not that I noticed? As there hasn't been a warning for low oil since changing the pcv.
I can't recall why I changed it but one of the spark plug holes were leaking so I took the rocker cover off to reseal and it fixed the issue and decided to change the pcv also. I got it from Febi on Ebay themselves, I'm sure it was to do with something I read on an audi forum and thought whilst I'm here why not..
My next test will be using dye to track where it's coming from but has anyone got an idea what it could be? I've also read that aftermarket pcvs fail, but I'm sure the car would throw a warning? Or would I have to use PETKA to check as it would be hidden? Also is there a test for pcv on PETKA to verify if its blocked or got issues? If so could someone share a screenshot/ instruftioms of what I need to do to test it please?
Also i noticed that one area (right side) of the pcv is oil stained already but the other (left side) isn't, not sure if this is useful information.
Also sorry for the long message, trying to be as detailed as possible. I've attached some images
