I was having some work done to my 92 Accord EX the other day and I asked the Certified Honda mechanic what he would charge to change out the spark plug wires. He said that as long as they didn't look worn that they shouldn't be changed. Does this make sense? As far as I can tell, the current wires are stock. I bought the car used so I'm not sure how old they are, thus my reasoning for wanting to put new ones on. Any thoughts?
d9h

 

If you feel like they need to be changed, change them

 

Does anyone know of a reason why I should not change them? I've never heard of not changing wires.

 

as long as you use a quality wire, theres no harm to be done by swapping them.

 

Probably something similar to the old saying if something is not broke then don't fix it. If the wires are not chewed up and are in good shape you should be fine.

 

If you have a multimeter you could test the resistance of the wires and then compare that to the manual. If the resistance doesn't match that of the manual then change them.

 

^ that

no point in paying to replace something that aint broke.

 

There's 2 different ways for plug wires to fail. Incorrect resistance, measure that with a multi-meter & compare against what they're supposed to be.

Then their insulation can break down. Even if the resistance is correct. Wait until after dark, & this works better with the engine thoroughly cold. Turn off all the lights & start the engine. Look for arcing around the cap & wires. It'll look like a dull blue glow. Maybe spray water from a windex bottle to make it more visible?? (If the arcing is across the surface of the cap, then replace the cap.)

 

Wow- a conscienstiuos mechanic turning down a half hour of easy work. Where is this guy located?

 

I've received similar advice from my Honda dealership. I changed my wires after 110k miles only when I noticed a miss when revving hard. I changed the plug wires and the miss stopped. Along with the suggestion of only quality, consider which brand. I've read threads about some brands not having a proper fit. I purchased Accel wires and the cap covers that seal the valve cover "holes" is not as tight as the factory wires. The lengths were perfect, they even fit in the wire guides on the cover. The fit onto the top of the plugs was perfect.

 

I appreciate the replies. It doesn't sound like it will do me any harm to change them out. Thanks.
d9h

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by d9h &raquo;</TD></TR><TR><TD CLASS="quote">I appreciate the replies. It doesn't sound like it will do me any harm to change them out. Thanks.
d9h</TD></TR></TABLE>

Nope, the most difficult decision really is which color to choose

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Then their insulation can break down. Even if the resistance is correct. Wait until after dark, & this works better with the engine thoroughly cold. Turn off all the lights & start the engine. Look for arcing around the cap & wires. It'll look like a dull blue glow. Maybe spray water from a windex bottle to make it more visible?? (If the arcing is across the surface of the cap, then replace the cap.)
</TD></TR></TABLE>

I agree. Yesterday I checked the resistance on my wires and they all checked good. They were 85* F when I checked them as opposed to the 70* F the manual calls out but I don't know how big of a difference that makes. Anyway, even though they checked ok they visually aren't so good. The outside of the wires look to be breaking down (little cracks in the rubber and looking dried out) where they go into the boots. I didn't check for arcing since it was still light out. But I'm going to replace them anyway when I do my timing belt and other things in a few weeks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TouringAccord &raquo;</TD></TR><TR><TD CLASS="quote">... (little cracks in the rubber and looking dried out).</TD></TR></TABLE>Yeah, looking for arcing in the dark is one way to find that stuff before it even gets big enough to see...

Resistance changes with temperature, but probably not that much from 70 to 85. If the resistance was borderline, then you'd want to measure it again at the right temperature. Unless you've got a Fluke, the temperature change is probably less than the meter-error. Usually when the resistance fails, it's WAY off.

 

no, the resistance on the longest wire was well within spec and just got lower as the wires got shorter.

I'll have to check for arcing tonight if I remember.

 

what resistance are we shooting for when testing the wires?

 

25,000 Ohms max at 70*F