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Spark plugs and wire--when to change

Do I need to change the plugs and wires on my 2003 Hyundai Santa Fe with 115,000 miles. I bought it new and have maintained it properly and its runs fine. When I go in for the free oil changes now, the dealer keeps trying to sell me plugs and wires for about$400.

Yes, they are due. Don’t use the dealer - $400! Get prices from some other places and at least one good independant mechanic.

Open the glove box, remove the owner’s manual, and read it and the maintenance schedule that accompanies it. The maintenance schedule will tell you when the spark plugs need to be replaced, which is NOW. The wires are probably optional, but if you don’t read the schedule you’re at the dealer’s mercy.

I’d also want to know about the timing belt, which is critical.

Good luck.

Good luck getting them out. They should have been changed at more like 60,000 or at least taken out and put back in.

I am much more of a “show me the defect” type person when it comes to plug wires. Can you really find a wire replacement interval in the owners manual? plugs themselves are on a schedule though.

I agree; 60k miles is about the limit on plugs. Wire could go longer based on a number of conditions; environmental, any misfiring plugs or other condition causing a misfire, etc.

Platinum, Iridium, or not, any plug can start to misfire at any time and some of it may not be noticed by the driver. The owner becomes acclimated to a lesser performing engine; just like they get accustomed to weak struts, a developing differential whine, etc.

If the plug(s) are seized in the threads from being allowed to remain in place so long then the cost to replace those plugs will go up dramatically due to the thread repairs that may be needed.
Makes me wonder just what else on this vehicle has been neglected.

If you have really driven the car for 115,000 miles without ever referring to the maintenance schedule, the number of items that have likely been ignored in addition to those 60,000 mile spark plugs is very significant. You will soon learn the meaning of the old saying, “Maintenance is far cheaper than repairs”.

I tend to agree with oldschool. At that age they are maybe getting there, but unless you are seeing a problem, you likely don’t need to replace them, yet. Generally when plug wires are getting ready to fail they will start demonstrating problems when it gets damp out.

Here is an idea. If you have a garage pull in open the hood some evening and leaving the garage door open start the car and look at the wires. If you see sparks, it is time to change them. If you have a spray bottle that you can put water in, then while it is running spray the wires. If you get sparks or if the car starts to stumble, then I would replace the wires.

When replacing wires I strongly suggest OEM wires as opposed to the fancy expensive ones often sold.  They look fancy, but frankly I have seen more problems with them than the standard lines. 

I also suggest going to an independent mechanic.  Dealers are no better (or worse) but almost always more expensive.

The plug wires you can do yourself if you like.  That auto parts store will have the parts and often can give you some instruction.

Thank you all for your answers, didn’t really clear the matter up since you all have different opinions. I did ask my non-dealer mechanic about it and he didn’t seem to think it was necessary so I was wondering if the dealer was just trying to make a sale. But those of you who got a bit snotty about doing regular maintenance and checking the owner’s manual–I have always done the recommended maintance on this car as scheduled. I just didn’t know about spark plug wires. Good grief.

I also agree…My 98 pathfinder has the original set of wires on them…340k+ miles…

I just wipe them down with a clean damp cloth every couple of months.

Soon to be moot since most cars these days are going to a distributorless system.

I can’t believe that any mechanic would recommend to NOT change the spark-plugs. Even the Iridium plugs need to be changed at 100k miles…and you’re past that.

I strongly suspect that the OP’s definition of “properly maintained” would not conform to what most of us would consider to be properly maintained.

And, his post did not make clear that his question was merely about plug wires. It appeared that he was asking about plug replacement, as well as plug wire replacement. Maybe he has replaced his plugs at 60k, as they are supposed to be, but it is all very unclear. And, perhaps the dealership is pressuring him to replace those plugs because they are coming due for their second replacement.

He did not want to be involved in the stripped threads issue which is likely to come up…Or the plugs are a NIGHTMARE to change…At 110K miles, I would change BOTH plugs and wires automatically. It might not even HAVE wires. A set of plugs is $20 and wires $30. Just do it…

Even if a mechanic looks at the plug pulses on an oscilloscope and they’re perfect (which is highly unlikely at 115,000 miles), plugs with over 100,000 miles on them still are pushing the limit, just because the longer the plugs are on there is the greater the chance that they’ll be seized to the surrounding metal.

Like Mike, I too am surprised the mechanic didn’t suggest changing them.

Ok, spbausch,
We can be reasonable. Don’t change the spark plugs or wires until the engine performance falls off and the gas mileage falls off. There might be added assurance by the check engine light coming on with a code. Then, you’ll know for sure.

It’s me again, the questioner. I agree–I need to change the spark plugs and will have that done ASAP. The wires, I am still not sure. The dealer says I really need to use Hyundai wires, not after-market ones. Any comments on that?

Every dealer I know of will say to use ONLY their part…no matter what the part is.

Hyundai does NOT make plug wires. They are made for them…probably Denso. Any good aftermarket set will be fine.

“I agree–I need to change the spark plugs and will have that done ASAP”

Once again, a vehicle that the owner adamantly claims has “had all recommended maintenance…as scheduled” turns out to not have been maintained very well.

Perhaps our recommendations to open the glove compartment, take out the mfr’s maintenance schedule, and to read and follow the maintenance schedule was valid, despite the OP’s protests to the contrary.

Postscript: I really hope that I am wrong, but the OP may find that the spark plugs have seized in their threaded holes, due to being left in place for far too long. If–as was earlier suggested by some other forum members–this does happen, the cost of this “deferred maintenance” can become much higher than properly scheduled maintenance would have been.

Great topic. I was getting ready to post a similar question. My wife has a 06 Toyota Sienna with about 48k on it. The maintenance schedule suggests 120k, but that seems far too infrequent. I was thinking something like every 50k or so.

I can only suggest really. But i would go with the supplier for Hyundai whichever manifacture that is. Or you can ask the Hyundai partsdepartment how much they charge. I know that for my Nissan Altima the wires are around $60, so i assume that for your car it will be about the same.