I'm pretty new to the site here, I've been driving my mx-6 since last june. A while ago I was getting off the freeway and slowing down to stop at a light. When I down shifted, it slowed the car way to much, so i looked down to see the tach sitting at 0. I got the car over to the shoulder, and it would turn over but not start. after tons of troubleshooting, i found that the timing belt broke. I pulled everything off from that passenger side and got into the timing belt and found why it broke. the front cam shaft sprocket has seized, will not budge the slightest, the whole cam shaft is seized. my question for the sixer experts of the site would be, what could have seized or happened to have caused this? what can be done? it's a '93 manual v6 ls with about 170k miles, is it worth it to look at just replacing the engine? I'm really out of my area of expertise when we're going this far into a car, so i would really appreciate any advice! Thank you!