Engine question

I have a 2002 Ford Taurus and I let my brothers use it one night. They drove about 90-100 miles. My brother said that they were going about 110-115mph and it only gets to 120. When they returned it, the engine had a knocking/ticking sound and the engine service light was on. Is this permanent damage or something that will cost a lot to fix?

Ouch. Sounds like a rebuild to me. Those engines aren't designed for running hard like that. I don't have to tell you how insanely dangerous it is to be running a car that fast when its not designed to do that, but it sounds like a rod or main bearing, maybe a head gasket blew leaving one cylinder scored and you have piston slap. Sorry for the bad news, but knocking is never a good sign.

I'm sure that car has a rev limiter and other sensors helping out. But yeah...sounds like a rebuild. I had the same problem. I just fitted a new engine