plug wires

eshoremd · September 29, 2004

when do you guys change plug wires. im getting a ruff idol when theres a lot of moisture in the air and raining. i got 52k miles. think i should change them? if so should i use stock ones or are the aftermarket ones that much better?

asilverblazer · September 29, 2004

I changed my plugs and wires at 100k because of a rough idle. Even after changing them both I can't tell a difference. I figured even still for forty bucks nothing bad can come from new ones.

budhayes3 · September 30, 2004

I replace mine every 60k or 5 years as preventive maintenance even though they will usually last much longer. I went with MSD 8.5's for the heck of it, but the factory equipment is more than adequate. You can visually inspect them periodically and check them with a multimeter to see if they're OK. I'm not sure what the resistance should be in the factory wires though, don't have access to my service manual right now. You can also remove the spark plugs and visually inspect them and check the gaps...I know that when I replaced mine my gaps ranged between .045 and .065, with the spec being .060. If you are noticing that the truck is starting to run rough, you might also want to clean the throttle body and the top end with Seafoam or GM top end cleaner, also, I like to replace my fuel filter every 25 to 30k.

intruder217 · September 30, 2004

Depending on year and engine you should get a check engine light and a misfire code when your wires are starting to fail.

MattDewalt · September 30, 2004

I replaced mine around 80,000. The new factory wires had a resistance of somewhere around 400 ohms if I remember correctly. The wires i removed all had resistance that measured in the low 100 ohm range. So, by my thinking, the wires were about 3/4 of the way worn out at around 80,000 miles.

2000Sierra · October 3, 2004

Wait a second.... wouldn't lower resistance be better? Wouldn't resistance increase with damaged wires? After all, if the wire had a break, the resistance would be infinite.

budhayes3 · October 3, 2004

Wait a second.... wouldn't lower resistance be better? Wouldn't resistance increase with damaged wires? After all, if the wire had a break, the resistance would be infinite.

<{POST_SNAPBACK}>

Yep

frdfandc · October 3, 2004

High resistance is what causes excessive voltage drop. The lower the resistance, the easier it is for the spark plugs to get proper voltage.

lip277 · October 4, 2004

I changed my wires at the same time as I did the plugs. I did the stock AC Delco for both. The wires looked "OK" but the plugs were a bit worse for wear. After I did them, I had to look at the tachometer a few times to make sure the engine hadn't died.....

Then again, the idle wasn't that bad to start with, but... I figured 4 years and 80k were enough. I also didn't want to get in there again (to do the wires) so I did them as a set.

Not bad. Just that right rear one was a pain to get access to. (At least I think it was that one - One of them sure was I remember....)