I know what it is....it is crankcase fumes and I notice in the cabin while at a stop lite or after I pull into the garage and shut off and get out of the car. I can also kind of locate it while the engine is running. Towards the back driver side. I've checked hoses etc. used a mirror and flashlite, but I just can't seem to locate the problem. Man these things have miles of plumbing! Any ideas will be much appreciated.
Oh......'03 A4 1.8t tip Q.
Thanks

 

It could be your breather valve leaking. This is what it looks like to give you a reference.

http://www.purems.com/products/product.php/II=1581

 

I have checked that over closely......it doesn't look like it had been replaced yet, unless they reused the clamps and I don't know if that is possible......where is the pcv located on the engine? I need to get a manual. I wouldn't have to ask these questions.
Thanks for the reply