Changing Platinum Plugs

The Sonata Manual calls for replacing the platinum plugs at 60,000
mile. If the car is running as well as it ever did and the MPG has
not gone down how important is it to change the plugs?. In other
words is this a case of "don't fix it if it ain't broken?"

Old_Timer

 

I can't speak for Hyundai, but my last couple of GM cars went a minimum of
100k and the plugs were still working OK. I change my LeSabre at 118,000
and there was no change in mileage or performance. My '91 Regal went to the
bone yard with the second set of plug in it and my LeSabre will do the same
it seems. The wires, however, did need changing as they were starting to
arc.

 

With the advent of catcons it is fairly important. A miss of any
significance can put enough raw gas out the exhaust to overheat and
damage the converter. A converter is MUCH more expensive than a set of
plugs, even the expensive platinum plugs, because most catcons have a
lot more platinum in them than the plugs have!

Matt

 

You may be thinking of iridium plugs, as platinum plugs aren't
particularly expensive at ~$20 for 4. For that matter, you can replace
them with NGK V-Power copper plugs, which are dirt cheap (under $10 for
4) and actually perform better than platinum or iridium plugs, they just
have to be changed more often (~ every 30K miles).

 

Matt's correct about the risk of damage to the converter. You can wait
until the plugs start to misfire, but you'll need to stop driving the car
right away (have it towed) and replace the plugs before driving it again
in order to guarantee you've done no significant damage to the
converter(s).

 

I have an 02 Sonata with 75,000 miles on it.
will change the plugs when it starts ot miss or 100,000, whicheve
comes first

The 2.7 liter engine is designed very poorly since the intake plentu
must be removed to replace the plugs. What were they thinking

Honda spark plugs are easy to get to and change

 

If it misses enough to be easily detectable by the driver, there is a
good chance you will trash the catcon before you get the new plugs in.

Matt

 

Iridium plugs will go well over 100K, don't know about platinum.

I would stick with the Mfr's recommendation.
-

Bob

 

I changed the iridium plugs in my 2001 3L V6 XG at just over 110,000km. I
had thought the car was running just fine but could definitely feel more
acceleration up these steep mountain roads where we live after the change.
The old plugs all looked OK just used with no real deposit build up or badly
eroded electrodes. 6 years on one set of plugs was good for me so why
stretch it.
BCinBC