spark plug wires: old but under 10kOhms

Hi,

I just check the spark plug wires on my newly purchased 1997 Civic:
they are from 1997, probably the OEM wires, and they all measured under
10kOhms. I will also look tonight with the engine running to see if I
notice any "sparks" around the wires, but I was wondering if I should
replace those anyway. I am trying to make small (read cheap!)
maintenace jobs, such as replacing the air filter, spark plugs, maybe
the rotor and the cap, and all these are under $20, however the spark
plug wire set is $47. If it is not absolutely necessary, I wouldn't
replace them.

What od you guys think?

thanks

 

Do not replace. Plug wires for the last 15+ years have a very long
life. You've measured resistance, it's fine. Too ofter people take
perfectly good OEM parts out, put in aftermarket, and can't figure out
why the great new part fails in a couple of years. This is one of
those instances where OEM is best and will last.

 

"Too ofter people take perfectly good OEM parts out ..."

Thanks, that's why I asked. I do not want to throw money down the drain
if not necessary!

As a side question, does anyone know why the resistance of these
"wires" is so high? Notice that I put the word wire in between quotes.
in DC, a normal wire of that length (let's say 30 cm) and that diameter
(a few mm) should have 0 Ohms (well, 0.1 Ohms or so, most Digital
MultiMeters would have trouble reading such a low resistance anyway).
but now KiloOhms. Why?, I understand that the "resistance" of the spark
plug is much higher, thus all the voltage drop will occur across the
gap and the spark forms there, however a lower wire resistance will not
hurt.

The only thing I can think of (and remember, I am not Auto mechanic at
all) is some soft of protection. Either to protect the coil, or perhaps
the auto mechanic? if the resistance of the wire was small, the current
would be higher, and possibly deadly?

Wait a minute, that doesn't work, what if I unplug the wire right from
the distributor and I put a nail in there, then the voltage there is
much higher, the resistance of the nail is virtually zero and very
dangerous for me.

 

You won't see the blue light show unless the wires are extremely bad.

The wires' resistance is fine, but after that age, the insulation begins
breaking down and current starts leaking off to ground before the plugs,
especially in the wet.

Replace them with OEM, along with the cap, rotor and plugs. Yes, it's
expensive, but how much do you value reliability and peace of mind?

 

To protect the coil.
http://www.tegger.com/hondafaq/badsecondary/index.html

 

Might also have to do with RF emissions, rather than protecting the coil.

 

it /is/ to do with rf emissions.

 

Sometimes I spray the wires down with a spray bottle. If the car starts
missing: replace. I have also been known to touch the wires and feel for the
current. Get Zapped: replace

 

After the above statement, do you really want to advertise your
"credentials"?

Oh never mind. The life of men...

 

Then is the rotor's resistor there for the same reason?

 

That's actually a pretty quick and convenient method of checking for bad
wires. I've used it too.

The voltage is bracing, but not at all harmful.

 

yup.

 

I'd sooner touch plug wires than an electric fence; had an cousin that
electricity didn't bother him. He'd tease his brother then grab onto a
e-fence and wait....

 

it's rudimentary, quick, gives me an answer, and it don't bite too hard.

 

Shadetree city. I wouldn't insure you. Matter of fact, if I were with ASE,
I'd try to suspend your certification.

 

Glad you're not. That's a perfectly legit method of checking for a wire
problem, Elle. Most mechanics I've ever spoken with, especially
old-timers with oodles of experience under their belts, do this.

 

It's a fun trick to play on newbies, too.
"Hey, hold this wire for me, will ya?"

 

LOL! When I was in high school I was reputed to be an electrical wizard
(I was). Word was, don't mess too bad with Abe or he'll electrify your
doorknob! (It was boarding school.)

 

Of course for the "Correct" way of doing this, you pay for the spray bottle
of "liquid" to spray on the wires and look for the sparks. By paying for
something with a label, you acquire "the right way"

 

As a Mechanic, we get paid "by the job" Anyway to get answers to questions
quickly to get the right conclusion helps.
Water is a conductor. sprayed onto the wires it MAY cause a miss to start.
if it does there is a problem with the wires. Now I can also hook up 1500
dollars of test equipment to read the spark and resistance in the wires. But
if I have a known bad wire to start with and I found it quickly, why waste
time.
The same with feeling the wires. A small jolt of electricity answers a
question. Is the wire leaking?
There are other things we figure out that sounds strange... but do they
work? Yes. And that's what we get paid for.