Sunday, January 7th, 2007 AT 4:18 AM
Mazda Protege 2001, 200K miles. Engine runs well at low speeds but knocks at high speed and "Check engine" light comes on. Mechanic suspects I might need "valve work" but not sure. I can drive around town, but not on the freeway because of the hard knocking sound at high speed. What do you think?


