The check engine light came on yesterday on my wife's 99 RX-300, and the
engine was missing badly. It happened all of a sudden; had been running
perfectly until then. I took the car to the nearest Toyota dealer, hoping to
get it fixed quickly and inexpensively as opposed to a Lexus dealer, which
is farther away, and requires an appointment. I don't have a code reader, so
I couldn't determine what the problem might be ahead of time.
They quickly diagnosed a failed ignition coil on Cylinder #1, but also said
that all the spark plugs we fouled, and the engine required a
carbon-cleaning procedure that cost $200, in addition to the $300 to replace
the coil and all six Iridium spark plugs.
The car has only 65K miles on it, and has been maintain by the book. It is
out of warranty, because of it's age. We bought it CPO with 24k mi. on it
in May 2002. The original service date was 4/23/99.
Question: Was it really necessary to replace all six plugs? Spark plug
replacement isn't called for until 90k mi. according to the Lexus
maintenance schedule. Also, was the expensive carbon-cleaning procedure
really necessary? Why would all the plugs be fouled after only 65k mi.?
Dealer's Answer: The plugs needed changing because of the age of the car,
not mileage. The carbon cleaning was necessary because of the use of
inferior gasoline containing 10% ethanol. The car is used only for short
trips, therefore never gets combustion chambers clean.
I add a bottle of Techron every four months, when I change the synthetic oil
and filter.. We only use name-brand regular grade gasoline. The car is only
driven about 6-8K per year. Did I over-spend for this service, or is the
dealer correct in his assessment?
Another maintenance item on the 90K service is the timing belt. Should I
also have this changed right away, or should it last until the car reaches
Thanks for your opinions!
99 Lexus RX-300
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