About 3 weeks ago, I went to a park which did not have paved parking area. Every car was parked on mud/sand/stone area. My car "hit" a pot hole during parking - slow speed. Since then, I always hear a rumbling noise when driving car at slow speed with all windows up. At high speed, I could not hear the noise with all windows up but car did not feel running smooth on highway. Alignment was fine though.

What could be the source of rumbling noise (at low speed) and rough ride (at high speed) ?

Thanks.

 

If it was a small hole I would t think that you have damaged a suspension component but I would take the wheel off and check

It sounds like something has dislodged in your engine bay

Hoses made of plastic often become brittle and can break when touched so it could be anything like that

Sorry I couldn't bee more helpful
Maybe if you post a small video of the noise it can help us more

 

After replaced all 4 tires, no more rumbling sound at slow speed and riding at high speed is smooth and solid.

Thanks for all the suggestion and comments.