The Gates listing in the first post on this thread is not entirely accurate. (BITOG friends overseas, my comments are about US-spec cars, though I'm sure you knew this.) The 1.3 L four used in the Ford Festiva and its replacement, the Aspire, is not indicated as an interference engine, but believe me, it is. My '88 Festiva had dire warnings in the owner's manual about major engine damage if the timing belt was not changed at 60,000 miles, and I know of at least two other Festivas that suffered engine damage when the belt broke.
Also, most Mazdas and Toyotas on the list are not indicated as interference engines. My understanding is that most if not all of these engines, especially the fours,
are interference. Mazda designed the Festiva/Aspire engine, by the way, which should be a clue. Note that the Hondas and Nissans generally have interference engines; why would Toyota and Mazda be greatly different?
In addition, Ford does not have a 60,000-mile recommendation for timing belt changes for the 1997 and up Escort 2.0-liter "CVH" SOHC. There is no mileage given. A dealer chart issued later gives 120,000 miles for this service for the SOHC. The SOHC is correctly indicated as not interference. The belt in my parents' 1996 Escort with the closely related 1.9 L CVH broke at 108,000 miles with no internal engine damage. The 2.0 DOHC Zetec is a close cousin: the block is slightly taller than the CVH, but the bore centers, bore, and stroke are all the same, and the oil filter is in the same location on the block. So my guess is that the Zetec is not interference, but this is
only a guess.
Now on to what is probably a touchy topic. Let the flame wars begin! If the feds are going to meddle in car design, why couldn't they meddle to benefit car owners by mandating noninterference engines, etc.? On the Focus with the 2.0 Zetec, at least one gearhead magazine has reported that the timing belt cover is jammed against an engine mount or some such and will probably be cracked or broken upon removal to get to the belt. In other words, when a shop replaces the timing belt, figure on replacing the cover too.
Why is this allowable? My Festiva had a 3-hour labor time for the belt change, which involved taking the engine off a mount, etc.
Why should a regular maintenance procedure take so long and require so much hassle? Shouldn't the feds mandate a little more in these areas to benefit owners and those who maintain their own cars?
Please understand: I'm not necessarily advocating government involvement here, but I'm throwing the thought out to get reactions.
