Why to avoid cars having rubber timing belts
Premature failure of rubber automotive timing belts can easily
cost two or three thousand dollars of repairs, possibly
including a new engine. Therefore knowing the true mileage of a
used car is imperative. Cars having 4 or 6 cyl. engines may have
rubber timing belts and should be avoided.
Be warned Five years ago an international oil company survey
found that 50% of off-lease cars had their odometers illegally
turned back and suggested consumers avoid buying off-lease
(used) cars, or leasing used cars having uncertain mileage. If
the cars really had 50,000 miles, and the odometer read 30,000,
then the timing belts would fail long before the new owners
expected them to fail.
What is an "interference engine"? Rubber timing belts are
usually used in "interference" engines in which the valves open
further and project further into the combustion chamber than in
a "free-running" engine. This allows outside air at atmospheric
pressure to flow faster into the combustion chamber through the
larger valve openings, allowing the engine to inhale more air,
be smaller and still create as much power while reducing its
manufactured cost and guaranteeing future repair business for
the dealer.
If a rubber timing belt breaks while engine is running, some of
the valves stuck in their open position will smash into the top
of the pistons, thereby breaking or irreversibly damaging one or
the other or both.
How to find out if the engine is an " interference engine". The
salesperson may not know; ask the Service technician. Better
yet, go on any search engine and type in "interference engine
list" because asking the Dealer's service technician may not be
reliable. If he says it does not, have the Dealer's Sales
Manager (not the salesperson) say so on the purchase order and
personally sign and thereby guarantee his assertion. For
recommended replacement mileage of rubber timing belts, connect
on the Internet to Gates Rubber Company, a worldwide
manufacturer of such belts. On its web site, click on
Replacement parts/automotive. Look for "timing belt replacement
Guide".
Get a written guarantee to cover premature failure of the car
engine's timing belt. Because most rubber timing belts on car
engines should be replaced at 60,000 to 70,000 miles to avoid
the engine self destructing, insist on a written guarantee from
the seller to guarantee replacing the timing belt at no charge
if it fails within another 20,000 miles. If the seller won't
guarantee it then he's admitting that the mileage may be
inaccurate and by implication may have been turned back.
Consider a compromise, such as a $300 price reduction on the
vehicle. If not acceptable, walk away.
Replacement cost Simply replacing a rubber timing belt even at
recommended mileage can cost $400 + dollars. Before buying any
car, especially 4-cylinder foreign cars, or even a 6-cyl. BMW,
be aware of the unavoidable cost of $400-$800 to replace a
rubber timing belt at recommended intervals based on mileage or
car age.
That's assuming the timing belt didn't break. If it breaks
(always while the engine is running) then internal engine damage
will take place catastrophically. If a timing belt on an
interference engine is not replaced at recommended intervals,
the repair cost when the belt breaks could increase to $3,000 to
$5,000 to replace the entire engine. The sales person will
invariably not mention that an interference engine powers the
vehicle and may not even know what one is.
The sad part of this problem is that it is not possible to
detect timing belt wear without substantially tearing down the
engine. The timing belt is literally a "sleeping time bomb".
Therefore, always buy the cars with "free-running" engines