Timing belts and interference valvetrains together spell disaster when failure occurs. Valves drop into the combustion chamber where they collide with piston tops. Bent valves or cylinder head damage will result. Ouch. Certain manufacturers like BMW, Infiniti, and Nissan have eliminated this flaw from their current product portfolio. But there are still a lot of car makers that use timing belts such as Acura, Audi, Honda, Lexus, Toyota, and Volkswagen.

If you happen to own one, and you look in your owner's manual and you see that you no longer have to change it at 60,000 miles but rather 90 or 100,000 miles, and you are really happy about that? Well, no so fast. There are other things that go wrong with a timing belt. Of course the timing belt itself has to be replaced at the time or the mileage in the owner's manual, whichever comes first.

It has always been a standard procedure to replace the water pump. Now if the timing belt drives the water pump, that means the pump is behind the belt and if the pump were to fail, you would have to take that new timing belt off and do the whole job over again. So remember, replace the timing belt and the water pump at the same time. You'll be glad that you did.

Additionally, we have timing belt tensioners, sometimes known as idler pulleys. Well consider this. In the old days when timing belts were changed at 60,000 miles, it was no problem with a tensioner going around 120,000 miles. They would generally last through two timing belts. But now you have a 100,000 mile timing belt on your car and you have a tensioner designed for 120,000 miles. There is no way that these components are going to last through two timing belts. They are certainly not going to last for 200,000 miles neither.

So that means to do a complete timing belt job right, always replace the parts that rotate with the timing belt at the same time as the timing belt itself. Keep that in mind. You don't want to be the guy on the shoulder of a busy interstate with the hood up and hazard flashers on during a lightning rainstorm. Bottom line, preventive maintenance is the sure smart way to keep that stylish car from an early mechanical grave.