Audi A4 - Oil in the cooling water / liquid? - Peter D
Most probably a failed oil cooler so not to expensive to fix. Mind you a bit early as it is a 2007. It could be a HG problem but the oil cooler can be tested quite easily. Regards Peter
Audi A4 - Oil in the cooling water / liquid? - Crasher
Highly likely to be the oil cooler, a well-recognised problem covered by Audi under their Technical Product Information notices (TPI’s) 2006187/12 and 2009047/7.