Maryland 'Z Club

A Timing Belt is a Timing Belt - Right?

As the owner of a Z car repair shop I get a lot of phone calls from folks price shopping for a 300ZX timing belt replacement.  Sometimes, after quoting the price, I'll hear something like, "Oh, Jiffy Tune or Precision Lube or fill-in-the-blank only charges 'x', how come you charge more?".

The purpose of this article is to explain what constitutes a long lasting timing belt replacement job.

A timing belt is a ribbed rubber belt that connects the crankshaft and the camshafts.  Beginning in the 1980's automobile manufacturers began converting from timing chains to timing belts in an effort to make engines quieter.  The drawback to this arrangement is that unlike a timing chain with a life expectancy of more than 100,000 miles, a timing belt must be replaced every 60,000 miles.

What can happen if I don't replace my timing belt?  If you don't change your timing belt and it breaks, which it eventually will, the valves and pistons inside your engine will collide.  This will result in catastrophic damage that could cost in the thousands of dollars to repair.  Unless you are a gambler, this is not a risk to be taken lightly.

A little bit of my car repair philosophy:  when I repair a system I try to think of the future.  In other words,  what can I do to make this system perform as designed for as long as the intended life expectancy?  In the case of the timing belt system, and it is important to think of it as a system, I want all of the related components to last as long as the replacement timing belt.  I don't want to repeat my labor in a week, month or year because I failed to replace a component of the system.

What related components should we renew when the timing belt is replaced?  Of course, the alternator, power steering and air-conditioning belts must be replaced.  After all, they have to be removed in order to gain access to the timing belt.  It's foolish not to replace the water pump as you would have to repeat most of your labor to replace this part at a future date.  Remember, water pumps generally have a life span of less than 100,000 miles.  That leaves the belt tensioner and, in the case of the mk2 (1990-1996), the idler pulleys.  Think of these parts as bearings and as such their  failure will lead down that big repair bill highway. 

So, the next time someone quotes a price to replace your timing belt, be sure that their estimate includes those parts necessary to guarantee miles of worry free motoring.

Mike McGinnis
Banzai Motorworks