One problem related to blown head gasket has been reported for the 2006 Nissan Altima. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Nissan Altima based on all problems reported for the 2006 Altima.
Check engine light came on about 2 days prior to incident. Went to a friends house, while slowing down for a speed bump car completely shut off. After leaving house car acceleration was very hesitate, took it to advanced auto to get the codes read on the car and it came back p0345 camshaft position sensor malfunction and p0430 catalytic converter failure and cylinder 3 misfire. So I called Nissan because I went online reading about recalls on the 2006 Nissan Altima engines but they told me that mines was not one of them. Changed both camshaft sensors and cylinder 3 coil. And car still acting like it doesn't want to start and stall. Took it to my mechanic and the way it looks I might have a head gasket blown. Crazy because researching on the internet, I see a lot of Altima owners are having the same problem.