I need help figuring out what is wrong with my moms odyssey. It started after I took it for a short drive with a small 5x8 trailer. I parked in the street to unhook the trailer and when I went to start it to pull it in the driveway it was acting strange. There was a loud knock coming form the engine, and it wouldnt go into drive or reverse, the engine appeared to be visibly shaking back and forth, then after probably 10 seconds just conk out. I realized there was no coolant and a puddle in the driveway, where it had been parked before I drove it, I added coolant and after it cooled down it started up and pulled in fine. So I know there is a coolant leak, but I am wondering if there is more serious engine damage now, or what could have been making that knocking sound

 

I had a nice response typed up but one wrong keystroke lost it all.

In a nutshell - take (i.e. tow) it to a reliable mechanic. You may have some overheat issues/problems. There are a bunch of things that could be wrong.