They do break but not as often. From a quick google search, I find quite a few posts saying that the ecotec is an interference motor. It still am not at all concerned as the chain will probably last the life of the motor.

 

There's a few factors that make the difference as to whether an engine has interference -
a)valve stem angle - the further off axis they're positioned, the further down the edge of the valve sits at -
b) peak valve lift - high cam lift or high rocker ratio in non-direct acting cams
c) compression ratio - the higher it is, the closer the piston gets to the top of the smaller combustion space
d) bore/stroke ratio - a long stroke makes the combustion chamber taller relative to the valve lift

So a long stroke, low compression, low valve lift engine with the valves set inline with the cylinder bore (and hence a significant bend in the ports) is likely going to be a non-interference engine, and a pretty poor performer too. Any deviation from this makes the likelihood of interference greater, and a modern high revving, high CR, DOHC, high output engine is pretty well guaranteed to be. I don't know for certain but I'm pretty sure that the Ecotecs are (maybe some odd displacement configurations with longer bores, or low CR for forced induction won't be). Bottom line, assume all modern engines have interference, never trust a belt beyond its design life (or less if the engine is leaking oil, which degrades the teeth), and replace a noisy chain ASAP. Poor timing costs lives (of engines).

 

My last car was a VW Jetta TDI. I had the dealership replace the timing belt and the idiots bent the valves. So I am just glad my HHR has a chain. If the chain breaks I can buy a new engine for less than that P.O.S. cost me. Buy American...They may break but they are cheap to fix

 

whooops my bad. guess i should study harder in auto class next time.

 

I broke a timing belt on a Ford Escort back in the mid 80's. Catastrophic damage that was.

But not nearly as bad as having to explain why I snuck out and "borrowed" my sister's car in the middle of the night. Before I had a drivers license. And the case of beer in the back seat. lol.

 

Sure you had a 'life or death' excuse for that one.

Ford spent close to a billion dollars developing the CVH engine (hey, it's a Hemi!). Not a great investment, but it was in production for a long time.

 

You know it was a simple question. I didn't make any statement about the life of a chain or a belt etc etc. I was just interested in knowing a little data about the engine.

 

Funny how that works.................