The use of a timing belt in place of a timing chain has been around for decades on imported car engines. The biggest drawback of using a belt, of course, is its age limitations due to wear & tear, chemical breakdown of the rubber and heat stress/drying of the rubber.
Unfortunately, few people are aware that timing belts should be replaced as part of routine maintenance. Fewer still are aware of the mileage levels at which they should consider routine replacement.
Most timing belt engines require timing belt replacement at around 60,000 miles, although some cars require replacement at a much lower and a few at a higher mileage level. Check your car's owner's manual for the recommended timing belt replacement interval for your specific model so you can plan to have the work done when required. It's critical that you stay on top of timing belt replacement so you can avoid being stranded on the side of the road or, much worse, cause extensive and expensive damage to your engine.
Expensive damage can be caused to your engine: Many timing belt engines are "interference motors", which simply means that the valves would hit the pistons if not kept in proper timing. This is not a problem under normal operating conditions but if the timing belt were to break or jump off the gears, the valves of one or more cylinders would strike the pistons and cause severe and costly damage.
If your car has more than the recommended mileage on the timing belt, you may be operating your car on borrowed time and the cost of replacing the belt is MUCH cheaper than having to rebuild or replace the engine because of damage caused by a snapped/worn timing belt.
Parts can be hard to find to repair damage caused by a failed timing belt: It's obvious that timing belt replacement as a preventive maintenance measure is often ignored. This is so prevalent, in fact, that many car manufacturers and engine parts manufacturers don't stock major engine components for timing-belt engines after the required 5-7 years because there will be only a handful of these cars still on the road. It can be quite difficult to find crankshafts, pistons, connecting rods, camshafts and the like for these older engines due to the economic infeasibility for the manufacturers to continue producing these parts for the few cars that they estimate will still be on the road.
In fact, many car manufacturers don't expect timing-belt driven engines to last through more than two timing belts or approximately 120,000-150,000 miles and, moreover, they actually expect many to be taken out of service with the original belt still installed. Sadly, there are hundreds of thousands of 85,000-90,000 mile timing belt cars in junkyards because the timing belt was never replaced. What a waste when these cars could still be enjoying a useful life had the owner just paid attention to the recommended mileage replacement intervals for the timing belt.
Unfortunately, the job of replacing a timing belt, especially on front-wheel drive transverse-mounted engines, can be difficult for a DIYer (do-it-yourselfer) because of the specialized tools that may be required.
However, most DIYers with a moderate amount of mechanical knowledge CAN do a timing belt replacement with guidance from a shop manual and proper planning. Planning ahead will save a lot of time and headaches.
Although it's more expensive to have the work done by a mechanic due to the labor hours required, you should always remember that the cost will always be considerably less than the cost of buying a new or rebuilt engine if you choose to forego the timing belt replacement beyond the recommended mileage interval.
Whenever you are replacing your timing belt, be sure to also replace the following related parts at the same time:
- Timing Belt Tensioner(s) and/or Tensioner Roller(s)
- Water Pump (if timing-belt driven)
- Front Engine Seal(s) on the Camshaft & Balance/Auxiliary Shaft (if so equipped)
The labor time involved in getting the timing belt changed is often high; changing these other parts at the same time only adds to the repair job the cost of the parts since the additional time is negligible when you're already investing the time on the timing belt change.
With regular oil changes, routine scheduled maintenance and regular interval timing belt replacement, most timing-belt engine cars can potentially provide you with at least 200,000-300,000 miles of trouble-free service.
In the final analysis, when you consider how much it would cost you to buy a new car or a new engine for your existing car, replacing your timing belt at the recommended mileage intervals is cheap insurance indeed!
When preparing to perform a timing belt replacement on your car, here are the parts you should consider having on hand:
Some cars may also require specialized tools, which is why it's always a good idea to do your research before attempting this repair. Check your owner's manual and an appropriate repair manual for your car to educate yourself on everything you'll need to start this maintenance job.
Repair articles are added regularly. Come back often to check for new maintenance topics.
These repair tips are designed only as a starting point. Please seek the assistance of a professional mechanic for all repair problems beyond your capabilities.