Should I replace the spark plug wires on my van? it has 150k miles and has never had them replaced. and if I should replace them, should I buy the premium wires or are the cheapest ones sufficient?
thx
On one hand, no point fixing something that ain’t broke. On the other, considering everything has a limited life span and the low cost of the wires, I’d replace them. OEM quality would be fine IMHO.
They’re cheap, so if it bugs you replace them. Get OEM replacements and do them one at a time, and when you do you might as well replace the plugs, making sure you gap them properly.
But as SanDiegoTim said, why bother as long as the van still runs properly? Unless it’s a mileage-based maintenance item in your manual there’s really no reason to change them.
Wait until it is dark out, then open the hood, start the engine up, and spray some water from a light mist type spray bottle. If you see a lot of arcing, it’s time to replace the spark plug wires.
At 150k I might just go ahead and replace them anyway. I’ve usually ended up replacing them somewhere between 150k and 200k on different vehicles that I’ve owned.
I agree with the others. The regular OEM wires are fine. There’s no need (IMHO) to shell out extra cash for premium wires.
At 150k I’d do it just for peace of mind as well as the belts if they’re original.
A lot of arcing? Make that ANY arcing. If the plug is firing to ground via a bad wire the cylinder is misfiring. Misfire can destroy the converter in very short order.
Converters are spendy.
At over 100K I would change the wires anytime they get disturbed. The reason is that due to heat the wires get stiff and brittle. On high mile cars it is not uncommon to do a plug change and a couple of days later have a dead miss due to a wire failure.
With very rare exceptions I go with OEM wires.
At that mileage, replacement as preventive maintenance is a reasonable, I would even say wise*, thing to do.
I would not recommend using the cheapest wires available – they’re likely to be more susceptible to problems and not last as long as better quality wires. Premium grade aftermarket wires should do just fine. Actual OEM wires (from a dealership) will do fine and fit exactly to boot.
*If a misfire develops from old plug wires, the cause won’t usually be obvious. Testing will be required to determine whether it’s wires, plugs, coil, or injectors. If replacing the wires prevents a wire-caused misfire, it saves you the testing fee.
What kind of van is it? Most vehicles don’t even have plug wires anymore.
Back ten years ago when I worked in a shop attached to a used car dealership, we were supposed to test all plug wires for resistance, if it came in higher than 10k ohms (I think, but I could be wrong), we replaced the whole set with OEM plug wires using contact grease on the fittings and OEM plugs. The place I worked tried to do things on the cheap usually but this was the golden exception. My brother was the owner and an ASE mechanic, and said that using non OEM plugs can cause serious problems in older cars, especially going from standard copper to platinum plugs. The newer higher powered plugs, he put it, could essentially burn holes in pistons and he had to rebuild a few engines because of this. The plug wires had to be OEM as well because he said that half the time the cheap ones already had micro-cracks in them and the other half the fittings would crap out way before they should.
Of course, YMMV and all that.
Is gapping still recommended? I bought a gapper for my spark plugs a few years ago, and I remember being told it’s no longer necessary nor recommended to gap spark plugs (at least not the iridiuim ones I was buying). What’s the scoop here?
Some of those platinum and multi headed spark plugs aren’t gappable, but the standard AC Delco or NGK plugs you see on a lot of cars are the regular style. If you car came with one of those regular standard ones and you want to upgrade it for one of the platinum or iridium ones, I wouldn’t recommend it according to the advice of my brother. Just keep it with what it was designed for he says because the newer style plugs “fire hotter.” I had a 2000 Volkswagen Beetle that was misfiring with the fancy pants plug, and the Volkswagen Dealership by my house suggested the AC Delco plug and gave me the part number. It fixed the misfire on the 3rd cylinder. I couldn’t tell you the logic behind why that fixed it but it did.
When I go to get plugs for my cars, the guy behind the counter at the parts house can look on his computer to get the recommended spark plug gap. My 2007 Nissan Xterra has recommended spark plug gaps written on a sticker under the hood of it. I haven’t changed those plugs out yet, but I am assuming they are of the standard sort.
Yeah, I have a Mazda 3 which takes iridium plugs, so I guess that must be it.