My daily driver (2002 Hyundai Elantra) has been running like crap. It was choking when you pressed the throttle and wouldnt respond when you stepped on the pedal. It has 67000 miles and my wife and I are the original owners.

I was up to date on all the maintenance stuff, and I had changed the plugs and wires recently to try and fix that spudder. Still nothing, and the car wasnt throwing a CEL either.

So I take it to the dealership before we left for vacation, and after they had it for about an hour the adviser calls me and tells me that the plugs are incorrect, and the after market plug wires I used when I replaced the plugs are not the correct resistance.

I told the guy that I used NGK plugs, and they are the correct part number and gapping according to the NGK manual, and the adviser told me that Hyundai spark plugs are "HOT" and that "COLD" after market plugs will not work. He said that the Dealership system computer rejected all 4 plugs during the diagnostic testing, etc.

Well, I didnt feel like arguing or worrying about it because i was packing the truck for vacation, I authorized them to do the tune up because I dont want the head ache. It is going to cost me $280.00 but oh well, its in the past. 1 hour labor at $90.00 plus parts, shop fee, and tax.

My question is, does the "hot plug" statement hold any water? I have never heard of this, and if this was the case then why doesnt NGK, or Autozone, etc. mention it or sell the correct spark plug?

I haven't picked the car up yet, but when I do if it chokes on itself I am going to be pissed and they are going to refund my money and put my "old" plugs back in.

This could very well be the case. people will post and disagree, but trust me, I've seen this many times in quads, bikes sleds, etc but rarely on a car. My Stang was picky for motocraft plugs. Didn't like aftermarkets. The Bronco can sometimes be picky.

I'll give you an example. My old Polaris sled(s). I swear, I could never get them to run the way they should on NGK plugs. I tried several different ones. They ran...just not how they would with the factory recommended Champions. It was very strange. I am a big NGK fan. I really think they have a quality plug and I feel the opposite about Champions...but I'll be damned that as soon as I swapped them all over to the factory recommended Champion plugs, they all ran like a T and I never had a fouling issue again.

My presonal beleif is that, for whatever reason, plug companies can't duplicate a plug. So Champions XXX plug is NOT equal to NGK's XXX plug although the companies may claim otherwise. The engine is designed to run based on what the manufacturer claims is the OEM part.

I guess it could be compared to going to Autozone to pick up an engine sensor vs. going to Ford and getting the OEM part. Sure, the AZ part may claim factory specs, but is it?

I hope the new plugs fixed your problem and that is where you will ultimately find your answer.

Me too. I just hope it wasnt something like a dirty TB or MAF sensor that the tech cleaned with a shot of carb cleaner, and in order to make his money he made up the spark plug BS.

I am trying to stay calm and not let these things worry me. I am really trying to stay grounded. I just dont trust the dealership at all, so I am fabricating scenarios in my mind and they are driving me nuts.

I dont know Jer, these cars can be tricky. I have an 03 Kia Optima with the v6 and the only plugs Ive found to work well are the Autolite double platinums. I tried 2 different NGK's (Iridiums and the factory suggested replacement), a set of Delco Rapidfires, Bosches, and even E3's. All of them either made the car run like shit or fouled rather quickly. The Bosch +2's and the E3's made the car miss enough to toss a CEL (not surprised by the gimmick plugs). The dealer couldnt even explain it. I wound up talking to the head mechanic at the Kia dealer. He suggested I try the Autolites. He told me that it was the best plug he found. Its been great ever since.

Now that I spent close to $200 on plugs alone, I found what works best for me. I just wish it was an old 302. I swear those motors would run on gum & paper clips if thats all I had.....

Since a majority of newer apps use plugs specifically designed for them, in terms of heat removal, and electrical resistance, you will find that. I used to have a 4-banger Cavalier with DIS that just wouldn't run on anything but Delco factory replacement plugs. I tried four different plug lines (Bosch Super and Platinum, Autolite and Denso), and I finally talked to a rep from Jacobs who used to work for GM, and he told me that the electrical resistance is the sticking point on GM factory plugs.
Basically, the ignition secondary has to have the right amount of resistance, or it won't work right. How's that for built-in necessity?

saturns are supposed to be the same stupid way. They use coil packs. they fire 2 cyclinders at the same time, it senses resistance in the wires and uses that to time the engine with fuel and spark. it is thier version of a crank shaft posistion sensor. It is f'd up. I tell ya.

I put in a set of regualy autolites in the wifes saturn and it still tosses a CEL once and a while. no ideas why it ever did it. I just put in new wires from vato zone going against everyones recommendations that the factory wires are the only ones that can be used. well needless to say, 5k on the new wires and 50k on the plugs and the CEL has not come on any more.

I would say it is very possible you need factory parts. do a google search on your car model year and engine and see what comes up in forums.

Me too. I just hope it wasnt something like a dirty TB or MAF sensor that the tech cleaned with a shot of carb cleaner, and in order to make his money he made up the spark plug BS.

I am trying to stay calm and not let these things worry me. I am really trying to stay grounded. I just dont trust the dealership at all, so I am fabricating scenarios in my mind and they are driving me nuts.

I don't trust the dealerships either. Now I don't think the tech makes money off sales. He most likely gets hourly. Now he might of cleaned a a sensor if the plugs and wires didn't work. Either to be helpful or because his pride got hurt.

That dealership is 2000% full of shit.

Elaborate...

I work at a hyundai dealer and i have seen this happen. Do you know what plugs you put in hyundai calls for NGK BKR5ES-11. Also they have problems with the TPS.

Elaborate...

First problem: incorrect resistance?!?!? :smilie_slap:twak:smilie_slap:twak and :enforce. Either they're resistor plugs or they're special ones for capacitive discharge ignition, but wrong resistance? I can't see a Hyundai/Kia/use-once-and-throw-away car having anything but the very cheapest ignition system on the market. Snowmobiles and other older small outboard motors have capacitive discharge ignition systems, but even most of those still use resistor plugs. The Champion part number prefix would be a Q instead of an R.

A 2002 Hyundai Elantra (G4CP engine) uses a standard resistor plug according to EVERY damn spark plug manufacturer I could look up online. The Champion (de facto) standard plug is an RC12YC. That plug is a standard resistor plug on hundreds of models of automobiles and trucks.

The factory NGK plugs are BKR5ES-11, and NGK claims, at the bottom of the application, that this plug is (from) the Original Equipment Manufacturer, and/or Original Equipment Service Part.

From the Autolite web site:

Part Number 3924

Product Type Resistor
Description Copper Core

Heat Range Chart Location D11
Hex 5/8"
Reach 3/4"
Resistor/Non-Resistor/Suppressor Suppressor
Seat Gasket
Thread Diameter 14MM
Tip Power
Pop Code A

Again, nothing special at all. Nil. Nada. Same plug used on both Infinity Q45 and GM's Quad4 motor, along with loads of other popular motors.


FINAL ARGUMENT: If the plugs were too hot, you'd be experiencing pinging at high load and speed. Eventually, you'd end up with holes in your pistons and other fun stuff, but this argument is COMPLETE BULLSHIT JER. Those RC12YC plugs are some of the coldest made. The 12 is the heat range. The only commonly available plug colder is an RC9YC. The guy is full of brown.

Hyundai uses RC10YC4 for Champion plugs not RC12YC.

Hyundai uses RC10YC4 for Champion plugs not RC12YC.

Not according to Federal-Mogul's website they don't. I cross-referenced NGK and Autolite numbers to RC12YC too.

Even if that were the case, it wouldn't stop the car from running right. The heat range of a 10 to a 12 isn't significant, and the 4 suffix is just a projected tip.

Just as reference, I'm using an equivalent to RS16YC spark plugs in my GT40P heads (Autolite 606's maybe?). Is that the right one? :shrug HELL NO. Well....not really. It's hard to say since these heads never came on a 5.8L. :toothless The right plug for the engine these heads were originally on is a RS14YC6. One range hotter on a higher-compression engine!!! Am I crazy?!?!?! No, I like to have clean, long-lasting plugs though. :D

Hyundai uses RC10YC4 for Champion plugs not RC12YC.

That is strait from a Hyundai service manual.

Well, all of the internets is wrong then. :rofl: Seriously, it doesn't matter. There's so little difference, you'd never know it just driving it.

His problem is more likely valve/cam timing related, a fuel pressure problem, etc. The throttle position sensor was mentioned as being a problem component as well, wasn't it? This isn't a spark plug problem no matter how you look at it.

Well believe it or not it worked. I saw the diagnostic report. I would not let them pull it out because I wanted to feel the cold start idle, and see if it bogged or choked. I drove it all afternoon and last night and it is running better than it has ever run in the last 3 or 4 years. I didnt mention that this is the third set of spark plugs in 3 years too. I originally replaced the factory plugs with some Bosch's, they threw the CEL after a few weeks. Then I was advised to use the NGK's, but they didnt work either, now the ones that are in it are factory NGK's and they make the car run perfectly. It doesnt make much sense to me, but the car is running and idling great, and it was $229.00 out the door which was cheaper than they originally quoted me. I checked and the plugs are new, and of course the wires are new too. Whatever they did worked and I am happy. $229.00 isnt enough money for me to worry about even if they did try to screw me so I am just going to let this one go and be happy. This keeps me calm.

whats the part number on the factory NGK's you should be able to get the same ones from vato zone.

Yeah I probably could. I will look on the receipt later and try to get the part number. I really dont feel like pulling the plug to try and find it there if you know what I mean.