The noise started earlier this year (I brought the car new in 2009). I can hear the clunking/ knocking noise sometimes when I am driving, but I hear it mostly when I stop. The dealer said it’s my car cooling down (exhaust), but the knocking noise is louder than just a car cooling down. Plus, I am just hearing the noise this year. Within the first year of me buying my car there was a recall for the front upper strut insulators which I had replaced at the dealership. I now have 35,220 mileage.
Hearing a clunking/knocking noise near upper front wheel on the passenger side. on 2009 Nissan Altima
Sounds like a bad upper front strut mount or bad front suspension strut. Get the dealer's mechanic to go for a drive with you so you can point out the noise you are concerned about.
I also have a 2009 Altima. It is in fact the car cooling down. I hear the noise more pronounced in warmer weather. The sound comes from underneath the passenger seat. No worries.