Questions and Answers

Mazda Protege Timing Belt Q. I have a 1999 Mazda Protege, LX. 1.6 liter 4 cylinder, 5 Speed manual transmission. It has 80,000 miles. My question, I have heard there are two different types of timing belts/engines. The one, if it breaks can cause serious damage. The other, the engine will stop, but there will not be any damage. Can you tell me which type this engine is, or how I could see for myself?

If it will not result in damage, outside of the inconvenience of being broke down, why not wait until it breaks?

A. There are two types of engines. Interference and non-interference.

In the interference engines, the valves and pistons occupy the same place in the combustion chamber at different times. So if the timing belt breaks and the camshaft stops turning, the pistons hit the valves and, at the very least, bends them. Worst case is the valves and valve guides break, and the pistons shatter.

In the non-interference engine, the valves and pistons never occupy the same place so there will be no damage.

Your engine is a non-interference engine and should have the timing belt replaced every 60,000 miles. And a vehicle with a manual transmission is more likely to break a timing belt than a vehicle with an automatic transmission..

Why not wait until it breaks? Suppose someone in your family needs immediate medical attention. You are on the way to the hospital and your timing belt breaks. Or you are entering a busy freeway and you just edge out into the mainstream and your timing belt breaks. Or you are coming home from work on the freeway and traffic is bumper to bumper and your timing belt breaks.

Sure, you can wait until it breaks, but when and where it breaks you'll never know. And remember, Murphy's Law has never been repealed.