Add me to the list of people who has blown through a flex plate. I have a 1999 Toyota Tacoma 3.4L 4X4 auto.I bought it used at 120,000 miles. I noticed a slight knocking in the engine bay but never took it too seriously. After about 17,000 miles and a couple of mud bogging incidents(possibly related) my flexplate went. I was on the highway doing about 2,000 RPM when i noticed a terrible noise, nearly that of a grenade beneath my car.

Obviously after that i couldn't get my car to start. So i towed it to the local mechanic and he confirmed it was a broke flex plate. He said that Toyota does not even mention such a thing happening and that he has never seen it.

As we speak i am having it repaired for $450 + the 200 dollar part. Any suggestions what this might be from? I considered possibly the crank to be somewhat at fault, but then wouldn't i be leaking oil? (which I'm not).

Just my 2 cents.

Thanks