Anyone had an issue where you can feel air coming back in front of the Mass Airflow sensor, where the air filter is and perhaps even get a P0100 error code. The car still runs well with no loss of performance that I can detect. The timing belt has been renewed and re-checked. There are no other errors that indicate VVT issues, so I am starting to assume worn cams or an intake valve issue. Would welcome advice on the next diagnostic check to perform - compression test, inspection camera in the oil filler hole?

I would suggest that with a P0100 code that you look at the performance of the MAF. The error is stating that the sensor is out of parameter and not giving the correct info. Please replace with genuine VAG product where possible (as there are lots of cheap after market sensors that give garbage information to the Engine)

Thank-you, that’s very useful to know. I’d assumed that as I could feel the blow-back the sensor was just confirming it wasn’t getting the airflow it wanted. I assume that situation would throw up a different code?