Hi everyone,

Today I was driving home on the highway after spending a few days up north, and out of nowhere, started hearing a strange banging / clanging noise that would happen sporadically and at random intervals.

I pulled over after noticing it, and took a look inside the engine for anything loose. Couldnt spot anything. Looked under the car, noticed a small drip right below the drivers seat– looks like coolant from the heater pump, but not 100% sure. I have a heater pump problem that my mechanic bypassed until I can fully replace it, but it’s nothing vital. No noise up until now. So what is it?

Continued driving home, and on the residential roads didnt notice any noise. Parked my car, checked back after an hour or so– no leaks under the car at all. So, I am stumped. Maybe it wasnt coolant, just condensation? Maybe it’s not the heater pump at all? Anyone have any insight on this?
1994 BMW 530i