Hi all, I'm new to this forum, but have been a die-hard Honda fan for over 20 years. I started with a used '88 CRX Si (the loss of which I still mourn), then to a new 1995 Civic hatchback (which was dependable but lacked character), and then to a new 2005 Civic 4-door LX, which quickly won my total devotion. Not the zing of the CRX, but everything about this car is solid, reliable, pretty, quiet, etc. I love the car and plan to keep it well past 10 years old, maybe even pushing 15.

What brings me to the forum is the question of when it is reasonable to have the timing belt and water pump changed. My car is currently just shy of its 7th birthday and 50K. According to the manual, the belt has hit the recommended age limit, though is not near the use limit.

A friend of mine, a seasoned mechanic who knows my driving patterns, has suggested that 7 years is a bit early for the change, but also suggested I try a forum such as this one to see what the experience of other owners has been as far as timing belt longevity.

Also, does anyone happen to know whether the engine in this car is the type that just stops working when the belt breaks, or actually incurs major damage when the belt breaks?

Thanks much for any information you can share. As I am not a mechanic and plan to keep this car into its golden years, I hope to meet others here who are doing the same.

 

IMO, you should change that belt. I have used belts up to 100K with no problems ever, but after 7 years I would suggest for it to be changed. And yes, if the timing belt breaks there is a high chance of severe engine damage. Of course, there have be cases where nothing wrong has happened after the belt breaking, but I guess it just all depends on the situation and your luck.

 

Happily, I don't have to depend on luck as to whether the engine gets half-destroyed if the belt breaks. It's apparently a function of what type engine it is. I knew of the distinction before, but my friend summed it up nicely:

On some engines (interference), a broken timing belt can lead to bent valves, this would be considered a major repair as the cylinder head must come off and get rebuilt. If a broken belt occurs at highway speeds, there is also a chance of piston damage. If your car is interference, changing the belt sooner rather than later is good insurance.

With a free wheeling engine, a broken timing belt leads to an engine that shuts off and won't restart (it will crank rapidly). Other than being stranded, no additional damage is done. If you car is free wheeling, changing later only costs you a tow and rental car.

I may give the dealer a call today to find out which type is in my car, but just wondered if anyone here would happen to know, and what the experiences of others have been.

 

All Honda engines are interference engines.

Belts break down both through use/mileage and by age. It may not be due by mileage but it's close to being due by age. You'll want to look into changing the timing belt, water pump, and belt tensioner soon. (All are done at once because you have to take the same covers and timing belt off to get to the pump and tensioner. Cheap insurance policy to get them all done at once.)

 

Darn, they're so near-perfect in every other way.

That makes the decision easy though, and I really appreciate your input. Everything you mentioned gets done at the next service visit, because I'm not that big a gambler.

Out of curiosity, why on earth does anyone build an engine like this when the other way is possible? Why not have all engines that simply stop instead of self-destructing when the timing belt goes?

 

Lots of different reasons, actually.

The main goal of an engine designer is to have as complete (read: efficient) use of the fuel/air in the cylinders as possible. If you bring the top of the combustion chamber (the cylinder head with the valves) closer to Top-Dead Center (the highest point the piston reaches on the crankshaft), you'll get a higher compression, and a complete burn that gets great fuel economy (because you don't need as much fuel/air to fill up that small space) and low emissions (since there's so little unburned fuel). The downside is that the piston and valves are closer together and will touch if they're not timed correctly.

If you were to space them far enough apart that they wouldn't touch, you need to fill the extra space with more fuel/air to get an efficient burn and make similar power.

For a more straightforward example, take a look at the fuel economy and emissions levels of a Honda, then find something like a Mazda (with a non-interference engine) with a similarly-sized engine and of the same vintage as the Honda. You'll see the Mazda's mileage is usually less, and doesn't get the lovely LEV (or even ULEV) designation that recent Hondas enjoy.

 

Makes sense -- thanks for taking the time to explain it. I have to admit, the gas mileage is but one of the things I love about my car.