What would make you change the wires when you change spark plugs?

[paulri]

I will be changing the spark plugs on my Civic this Friday. The wires were changed by my mechanic the last time the plugs were changed, at 150K in mid 2012. Should I change the wires also, automatically, or are there only certain signs that should make me want to change them? FWIW I will be having someone who has done spark plug changes with me when I do it, so there will be another pair of eyes on the stuff. Also, the wires are very easy to get to when I change the plugs--I don't have to take anything off when doing this, with the Civic, the first thing you disconnect are the wires. In other words, if I do need to change the wires in the future, they are right there, easy to access, so there really appears to be no reason to change them prematurely.

Here is the link to the OEM part , my mechanic put this part number on my invoice when they were done at 150K.

 

[Egg_Head]

I'd be more concerned with the condition of the cap if it wasn't changed last time than wires that have about 52K miles on them (according to your sig)

 

[The Critic]

Are you sure they used Genuine Honda wires? A lot of shop software programs will list the OE part number when the part was in fact aftermarket.

There are specs in the Service Info for testing of the wires. If the wires were replaced relatively recently they are probably still fine. This is assuming that you are able to remove them without damage.

Where are you in CA?

 

[WobblyElvis]

Agree with egg head. Cap and rotor are probably due.
I have maintained a few older cars for the last 45 years and have only seen a spark plug wire go bad once. I found the spark jumping to ground by looking under the hood at night. Cleaned the wire and wrapped it in electrical tape and drove the car two more years until I scrapped it. I'm not a believer in changing the high voltage wires.

 

[Gimpy1]

Wires should be changed if the boots are damaged or the outside jacket is damaged. These are usually damaged by pulling on the cable to take it off the plug OR in some cases heat damage from touching the exhaust manifold etc. Long term heat and age can cause the outer jackets to get brittle and crack which can cause misfires, especially with lower quality cables. I would look at the condition of the cables, check for cracks and look at the boots, are they in good condition, if they are, leave them alone, usually you will damage them during the removal. Also look at your owners manual maintenance schedule, in most cases it advises to inspect, but not necessarily replace. I have never had to replace wires because they wore out, I usually damaged them when removing the cable to change plugs.

 

[paulri]

High desert region of SoCal.

Originally Posted by The Critic


Where are you in CA?


I am not 100% sure, but my mechanic is very big on OEM parts--and the part & numbers were all hand printed on the invoice.

 

[paulri]

Just to be clear, when you folks say change the cap and rotor, you are talking about parts 2 and 3 in this OEM diagram, correct?

https://www.hondapartsnow.com/genuine/honda~cap~assy~30102-p54-006.html

 

[Egg_Head]

Yes. Be careful taking the wires off and use dielectric grease when installing the wires over the plugs. Not familiar with your vehicle, what is the recommended plug change interval?

 

[slacktide_bitog]

NGK wires are a nice blue color, and they are numbered too

 

[paulri]

30,000 miles, but I'll be installing NGK Iridiums, so I'll probably go 100K--and certainly closer to that than 30K.

Originally Posted by Egg_Head
Yes. Be careful taking the wires off and use dielectric grease when installing the wires over the plugs. Not familiar with your vehicle, what is the recommended plug change interval?

 

[Chris142]

Originally Posted by paulri
High desert region of SoCal.

.

 

[paulri]

Dielectric grease isn't application specific, is it--how about this: https://www.autozone.com/greases-an...5-g-dielectric-tune-up-grease/125419_0_0



Originally Posted by Egg_Head
Yes. Be careful taking the wires off and use dielectric grease when installing the wires over the plugs. Not familiar with your vehicle, what is the recommended plug change interval?

 

[StevieC]

If they are working and in good condition I'd re-use them. (Look in the boots for obvious signs of "tracking" where the spark is leaving the boot)

Take them off carefully. Slightly twisting in both directions and rocking them side to side as you take them off instead of brute force pulling them off will likely leave them in reusable condition. Always pull by the boot and never the wire itself.

They aren't hard to change should you need to in future anyway so the risk is low.

Use some di-electric grease on them before re-installation.

 

[Vaca]

Originally Posted by paulri
I will be changing the spark plugs on my Civic this Friday. The wires were changed by my mechanic the last time the plugs were changed, at 150K in mid 2012. Should I change the wires also, automatically, or are there only certain signs that should make me want to change them? FWIW I will be having someone who has done spark plug changes with me when I do it, so there will be another pair of eyes on the stuff. Also, the wires are very easy to get to when I change the plugs--I don't have to take anything off when doing this, with the Civic, the first thing you disconnect are the wires. In other words, if I do need to change the wires in the future, they are right there, easy to access, so there really appears to be no reason to change them prematurely.

Here is the link to the OEM part , my mechanic put this part number on my invoice when they were done at 150K.


Like a few others here have said, no, I would not automatically change the plug wires when you change the spark plugs. Even if they weren't already changed at 150,000 miles, I would not automatically change them.

I would only replace the wires if they were defective; either the resistance out of spec (pretty unlikely) or if physically messed up like loose connections or arcing evident or similar.

 

[Delta]

In my case I've always had a plug boots get stuck on the old spark plug. First case was 18 year old wire/plugs on my '87 Oldsmobile and the second case was the 17 year old wires and plugs on my S10. Broke just about every boot on both...

 

[racin4ds]

Be aware that the boots will ARC down inside the head in the spark plug tube on a Honda where you cannot see, I've seen MANY of them do that over the years of working on Honda/Acuras. I actually bought a car very cheap once because the PO thought it had a dead cylinder. Come to find out, the plug boot was arc'ing down in the head and dead shorting the wire to ground causing a dead cylinder. Put new wires and plugs in and it ran like new.

 

[CharBaby]

I've always replaced everything when doing an ol'school tune up. Plugs, Wires, Cap & Rotor, PCV.

 

[MRtv]

Originally Posted by Char Baby
I've always replaced everything when doing an ol'school tune up. Plugs, Wires, Cap & Rotor, PCV.


Yup. Same here.

 

[CT8]

Change everything. Do the job ponce.

 

[BrocLuno]

The only way I know test wires is with visual inspection and then an OHM Meter. If they show no signs of arcing and no cracking, etc., they may be good. Then meter them end to end, and if out of range, replace. Wires can last a long time, or go quick. A meter will tell you whether they are acceptable or not ...