Trouble Code P0306 2004 Santa Fe 3.5 Please Help

[MommaHyundai]

Hi I have a 2004 Santa Fe with the 3.5. Today I started it and the check engine light came on. It was not on before this. (We had a lot of wind and rain from the storm but nothing major.) And seems to be running fine. I went to the auto parts store and they ran a diagnostic and the Code P0306 came up #6 cylinder misfire. They said probably Spark plug, wire or coil for #6, then went to look up code in computer and did not have my truck so they went with Kia or Domestic, which gave different possibilities for a code P0306. They had me buy some fuel injector cleaner as injector was on the list. The light is still on so I guess the cleaner was not the magic bullet. I spoke to a lady at another auto parts store who is a wiz when it comes to cars and has been around them and fixing them a really long time. She says the Code P0306 is Spark Plug, wire, coil #6. She has a 4cyl Hyundai car not truck and she had the code for her #4 misfire in the past and she started her repair cheapest first, Plugs, wires her code was still there she then changed the coil and that did the trick for her.

I on the other hand can't do this stuff myself. Can't afford the dealer anymore or to have a shop do a tune up AND coil if I don't need all new plugs and wires just a coil as they will charge a lot to do a lot all. And it may not need it or even be any of those things. I also suspect the dealer and shops will want to still hook up their computers to do an costly diagnostic because the light is on, even though I know the parts store already came up with a code P0306 twice. Spoke to the dealer on the phone and he already basically said they would want to do that first for $100 plus the cost of repair.

I brought the truck new. It now has 91,500 miles on it and the dealer has already done two tuneups on it in that time, Plugs and wires. I hear it probably shouldn't have even needed these tuneups in this amount of millage? So the last one was probably about 2 years ago and a few thousand miles maybe a guess 10,000-20,000 miles ago. Do you think a plug and wire would be bad already in that few miles?

Do you think it is more likely the #6 coil?

Is it bad to ask them to change just the one Plug or wire if it is just one of those?
Do they all have to be done for 1?

Do you think what I was told about it most likely being the coil (Or Plug or wire) is a very good possibility?

Or do you think its possible something else and maybe something worse?
(I read the coil going on this model is common?)

Do you think a shop will charge a lot to put in a coil? The part is about $85 but I imagine they will jack that up too.
Is it hard in that model to replace the coil with #6 on it?

The truck will be driven down to Long Island from MA and back up (About 500-600 miles I guess) in about a week would it be risking damage or dangerous if driven down there before changing the coil if that's the problem or plug/wire do you think?

PS It is running smooth right now, I don't feel any change.

I have been laid off I am so low on money, this is the worse possible timing. So, any advice would be so appreciated. I have no garage I use I use to use the dealer till things stopped being covered. So I fear walking in a random shop with a check engine light and being a female and no idea about what it maybe and what would be a normal cost. Like the wrong shop and I have a target on my head in the shape of an $. So, please can anyone help guide me I am freaking out here. :'(

Thank you.

[Nightstalker2160]

Originally Posted by MommaHyundai

Do you think a plug and wire would be bad already in that few miles? It could be, but it's more likely they didn't change the plugs and wires at the last tune up. Did they give you the old parts after the tuneup?

Do you think it is more likely the #6 coil? No, because each coil fires two cylinders. In this case the #6 and #3 cylinders. So it stands to reason if it was a bad coil your #3 cylinder would be misfireing also.

Is it bad to ask them to change just the one Plug or wire if it is just one of those? No. Make sure you get the old parts to ensure they did the repair they charge you for.
Do they all have to be done for 1? No. Individual plugs, wires, and/or coil packs can be changed without causing damage to the engine.

Do you think what I was told about it most likely being the coil (Or Plug or wire) is a very good possibility? No, see above.

Or do you think its possible something else and maybe something worse? (I read the coil going on this model is common?) I would start with the plug first and have a reliable mechanic check it. It's an easy chech since the #6 cylinder is located at the front of the engine near the battery and radiator.

Do you think a shop will charge a lot to put in a coil? The part is about $85 but I imagine they will jack that up too.
Is it hard in that model to replace the coil with #6 on it? No, the coil is right in front mounted on the front cylinder head. I would expect no more than an hours worth of labor.

The truck will be driven down to Long Island from MA and back up (About 500-600 miles I guess) in about a week would it be risking damage or dangerous if driven down there before changing the coil if that's the problem or plug/wire do you think? It will not damage your engine, but it will reduce your gas milage and engine performance.

PS It is running smooth right now, I don't feel any change. Further indicator in my mind it's a plug, plug wire, or both.

I have been laid off I am so low on money, this is the worse possible timing. So, any advice would be so appreciated. I have no garage I use I use to use the dealer till things stopped being covered. So I fear walking in a random shop with a check engine light and being a female and no idea about what it maybe and what would be a normal cost. Like the wrong shop and I have a target on my head in the shape of an $. So, please can anyone help guide me I am freaking out here. :'(

Thank you.

Do you know anyone who has mechanical abilities? A spark plug check and change would take 10 minutes and cost about 8 dollars. Someone with experience would be able to tell if the plug or wires have ever been changed.

I'm not trying to scare you, but my experience has been not to trust dealers. My wife and father-in-law both paid a Hyundai dealer to do thier 60K tune up. I did the next tune up (120K) and it was obvious the dealer NEVER changed the back 3 plugs and wires on our 2.7l V6. To do that they would of needed to remove the intake manifold. They charged them for all that work, but didn't do it. This is at two different deallers. One in Tennessee and one in Georgia.

I would try to find a reputable independant mechanic or a person with some mechanical background to check it for you. May be as simple as new plugs and plug wires.

good luck

[sbr711]

Repair the misfire like last month... driving with misfire will kill a Hyundai catalyst real fast.. You will either get a cat efficiency code or an engine that cannot breath out the exhaust when the honeycomb start melt /chunking away and clog up the front pipe and downstream cat in the front pipe..

Coils on 3.5 is common,,, look at the plastic coil winding body, do you see a nice big grey/withe spot adjacent to the steel part ??

Do the wires look like they have a white haze on them like they been sprinkled with talc ?

Wanna test the coil theory ? swap the #6 coil to #2 cylinder.. see if the misfire change to a 0302...

[MommaHyundai]

Thank you Nightstalker2160 and sbr711

Nightstalker2160 to answer your question, no I did not get the old parts and yeah I know the dealer I purchased the truck from had ripped me off a few times. Said they did things that later I would be told by another place it didn't look like X,Y,Z was ever done. You are so right about that. I don't have a mechanic I use. There are some smaller shops around me and someone suggested our local cab company mechanics do some work on the side. I wonder if that is a good or bad place to try?

So, guys today I called the dealer that I'd been using the past few years (Since I stopped going to the one where I purchased the car because of what I said above.) I called to ask them to look up when and if they had a tune up on file for me (Because I thought I remembered having one there but could not find a receipt for it and wanted to know what millage it was done at.) They did not have a record of it either. So, maybe the first dealer did it and that would have been longer ago then I thought. Or maybe I am wrong and I didn't have one done ever.

Anyway, this dealer said they would put one plug in for me if that's what I want BUT if that's not it that's on me. I said its maybe the Plug, wire or Coil I'm not saying its one or the other thing. He said he would want to run a diagnostic test even though the auto parts said P0306 because maybe the parts store entered a number off for the VIN when entering it into the machine they use. (I went to 2 different auto parts and both got the same code and none put a VIN number in actually) and if they did that the reading would possible be wrong he said. He said on my truck the plugs and wire are rated for 90,000-100,000 miles so my 91,500 falls in there and I should do them all and all thee wires. He said it could also be a gasket that runs from the head to the engine (He didn't call it a head gasket or Value cover one but I forget what he actually called it think it stared with a P?) He said during a tune up they would do that gasket, plugs and wires. Its important on my particular Truck to do that gasket at this many miles with the tuneup because it could be leaking.

What are you thoughts on that gasket comment?
Is it true that there is a gasket that should also be changed on that truck at a tuneup?
And if that's not done because a non Hyundai mechanic fixes it and skips that I could have major problems later like he insinuated?

He also said the coil would be sluggish at a light maybe a plug would maybe cause a slipping feeling when the truck switches gears?
If true its not sluggish but sometimes rear but goes into 2nd gear a little slow like a short whine out then in.

So, I may not have had plugs and wires done ever after all or if so maybe long ago like 50,000 or so miles ago. This probably changes things huh and maybe it is the plug.

If I find someone and they think its the plug and I have them change just that plug should i at least get the plug from Hyundai instead of a random auto parts plug?

I am wondering if the genuine Hyundai plug is made differently to make it last 100,000 miles or would the auto parts store replacement be made to go that long too?

Same question if the wire is going to be changed dealer part or auto parts store the same quality/lasts etc?

Also, I wonder because, if down the line when the other plugs start to go and I maybe have to go for the rest of the tuneup when I can afford that I'll have all the same plug brands or if I have any motor issues later Hyundai can't say I didn't use genuine Hyundai parts (Plug, wire) or they see someone else did work on it by the auto part store plug and blame that. Or is that an unnecessary concern?

Thank you so much guys. Sorry for all the questions. I just want to go into this with some knowledge so a shop maybe doesn't rip me off again. I can't afford to be ripped off right now.

[MommaHyundai]

Originally Posted by sbr711

Repair the misfire like last month... driving with misfire will kill a Hyundai catalyst real fast.. You will either get a cat efficiency code or an engine that cannot breath out the exhaust when the honeycomb start melt /chunking away and clog up the front pipe and downstream cat in the front pipe..

Coils on 3.5 is common,,, look at the plastic coil winding body, do you see a nice big grey/withe spot adjacent to the steel part ??

Do the wires look like they have a white haze on them like they been sprinkled with talc ?

Wanna test the coil theory ? swap the #6 coil to #2 cylinder.. see if the misfire change to a 0302...

This may sound like a dumb question but just so I am clear, do you mean if the code is 0302 after switching the #2 wire to the #6 coil that means the #6 coil is bad?

Thank you for the pictures and the Cat warning too. That would cost a whole lot I imagine. I am worried and will look into getting if fixed first or cancel the trip if places are trying to charge more then I can afford to fix it right now.

I have had problems with this truck since day one. Its been so frustrating. I feel hopeful seeing people still going with like 150,000 on this model but I can't imagine mine will make that, not without breaking down every few months or having constant repairs. Think I got the bad apple in the barrel. Most people seem to have had good luck with these.

[johnaauld]

Originally Posted by MommaHyundai

This may sound like a dumb question but just so I am clear, do you mean if the code is 0302 after switching the #2 wire to the #6 coil that means the #6 coil is bad?

Thank you for the pictures and the Cat warning too. That would cost a whole lot I imagine. I am worried and will look into getting if fixed first or cancel the trip if places are trying to charge more then I can afford to fix it right now.

I have had problems with this truck since day one. Its been so frustrating. I feel hopeful seeing people still going with like 150,000 on this model but I can't imagine mine will make that, not without breaking down every few months or having constant repairs. Think I got the bad apple in the barrel. Most people seem to have had good luck with these.

Sounds like money is a big motivator for you. If money were tight, I would have a male neighbor(someone with a sparkplug socket) change out your #6 spark plug and wire. If you want to buy the whole set of wires now, you could just change out the #6 wire and hold on to the other wires til you had enough money to do the whole thing right. If will cost around $500 to change out all the spark plugs and wires. The reason it costs so much is that the "intake manifold" has to come off to change the back three spark plugs and wires(hence the gasket for the intake). A neighbor could change your #6 spark plug and wire in under ten minutes and would be happy if he got a beer out of it. You should be able to buy a spark plug and wire set for $80 or so.

[MommaHyundai]

Hi guys. I called my original dealer where I brought my Santa Fe new from and asked them to look and see if they have a record of a tuneup.

They said Yes. Said they did all the Plugs, wires and all 3 coils on my truck at 61,437 miles on November 30, 2009. (I now have 91,500) So, all those parts only have 30,000 miles on them.

(I remember the reason they did them was that the service manager at that time said it was the scheduled maintenance time for them. I was not having an issue with them as far as I remember.)

How much does this fact its only 30,000 on them not 91,500 change things?

Is it reasonable to have the Plug, Wire, or Coil on my model go in 30,000 miles on parts the dealer put in?

Now I am very worried its not normal and reasonable since this truck is supposed to be rated to go 90-100,000 on these parts. But, maybe its common that sometimes any of these can go in as little as 30,000?

The dealer I started to use for oil changes and some services after I left that other dealer said in a tune up they always change the Plenum Gasket too. (I called them to see if they had done plugs on my car too since I thought it was done twice they hadn't.) He asked if the original dealer changed the Plenum Gasket when they had done the Plugs, Wires, and Coil. I didn't know to ask the first dealer. I only asked about the Plugs, Wires and coil being done or not so I didn't know.) The 2nd dealer said if they hadn't done that gasket back with the tuneup maybe the P0306 code is that being bad not the Plug, Wire, or Coil and that's a BIG job and expense.

He also said if a Spark Plug (Wire or coil) is bad now in 30,000 miles he strongly feels I should have them put it on the ($100+) diagnostic machine so they can see what might be causing the plug, wire, or coil to go bad in only 30,000 cause there maybe a reason its so soon.

Would there likely be some bigger reason for the #6 Plug, Wire, or Coil to go in 30,000 or is it perfectly reasonable for that to happen?

I am sorry for all the questions its just I wondered if 30,000 vs the 91,000 I thought they had on them, may make a difference and wanted to get your opinion on all this and this new info.

Thank you so much.

[santa06]

You said the dealer replaced the plugs and wires and coils in the last 30k miles. I doubt they replaced all three coils , plugs and wires yeah ; if it was running properly there would be no reason to change the coils and the cost would have been really high.

As suggested cheapest route is to change the #6 plug first ; if still running crappy then change out the coil , leave the plug wires alone. My bet is the real problem is a bad coil. Good luck cheers.

[sbr711]

We dont see plugs as problem with 3.5L.. age kills the coils, see pics in post 3 above

Coils about $75 each, and there is 3 of them.. anybody look at the coil and find burn spot as seen in the forementioned pics ?

[MommaHyundai]

Originally Posted by MommaHyundai

Hi guys. I called my original dealer where I brought my Santa Fe new from and asked them to look and see if they have a record of a tuneup.

They said Yes. Said they did all the Plugs, wires and all 3 coils on my truck at 61,437 miles on November 30, 2009. (I now have 91,500) So, all those parts only have 30,000 miles on them.

(I remember the reason they did them was that the service manager at that time said it was the scheduled maintenance time for them. I was not having an issue with them as far as I remember.)

How much does this fact its only 30,000 on them not 91,500 change things?

Is it reasonable to have the Plug, Wire, or Coil on my model go in 30,000 miles on parts the dealer put in?

Now I am very worried its not normal and reasonable since this truck is supposed to be rated to go 90-100,000 on these parts. But, maybe its common that sometimes any of these can go in as little as 30,000?

The dealer I started to use for oil changes and some services after I left that other dealer said in a tune up they always change the Plenum Gasket too. (I called them to see if they had done plugs on my car too since I thought it was done twice they hadn't.) He asked if the original dealer changed the Plenum Gasket when they had done the Plugs, Wires, and Coil. I didn't know to ask the first dealer. I only asked about the Plugs, Wires and coil being done or not so I didn't know.) The 2nd dealer said if they hadn't done that gasket back with the tuneup maybe the P0306 code is that being bad not the Plug, Wire, or Coil and that's a BIG job and expense.

He also said if a Spark Plug (Wire or coil) is bad now in 30,000 miles he strongly feels I should have them put it on the ($100+) diagnostic machine so they can see what might be causing the plug, wire, or coil to go bad in only 30,000 cause there maybe a reason its so soon.

Would there likely be some bigger reason for the #6 Plug, Wire, or Coil to go in 30,000 or is it perfectly reasonable for that to happen?

I am sorry for all the questions its just I wondered if 30,000 vs the 91,000 I thought they had on them, may make a difference and wanted to get your opinion on all this and this new info.

Thank you so much.

Update:
I went through my receipts and discovered that the orig dealer actually did or says they had did all new plugs at 49,000 miles as regular maintenance and then again at the 61,000 miles I mentioned above because the check engine light had come on and they said it was the Plugs and coils and did them again. Also, my radiator hose was leaking that same day and they replaced that after. (Maybe that was the reason for the check engine light not plugs and coils that supposedly went bad in a little over 12,000 miles.)

So, knowing it wouldn't make a difference but being frustrated by this type of thing from them in other repairs in the past and the discovery of these questionable receipts again I decided I would stop at the dealer and at least bring this to their attention! ask why the plugs or coils lasted only 49,000 then 12,000 then only 30,000 miles when supposedly done by them and rated for much higher mileage.

The service guy I have dealt with before over the years was there I told him the story and he knew about past repair problems and even the issues with the old service manger having a reputation of charging for work never done. Same guy who did these receipts. So he takes me to talk to the newest service manager. This new service manager just keeps saying. "Who knows what happened the guys not here anymore and maybe they went bad. They did them at 49,000 and your coils went bad at 61,000 and that ruin those plugs again and that's why they needed to be replaced again. That can happen if the coil goes bad it ruins the plugs. You can't prove that's not what happened, what do you expect me to do about it now its 30,000 miles since we put them in now. You should have come back right after we put them in." Is he kidding I had no reason to know the future the check engine light only just came on. I said "If the plug is bad again you should replace that #6 plug, at least one of the times someone didn't change the plugs when they said they changed ALL of them each time and they charged me for it." He said "He's not going to do that. He won't change the plug if its bad. Only thing he would d is he would throw it on the handheld machine and check the code take a look and see if its the plug or coil without charge." I said the code is #6. He said the auto parts store could be wrong.

He (Well the mechanic while he stood over him) checked, it was still P0306 the code was right. They pulled the #6 plug said it looks fine and the coil looks fine.

Then they said they are taking the #6 wire and putting it on the #5 coil and the 5 on the 6.

He said drive it around a while see if the check engine light comes back on. If it does they will retest and it shroud then say P0305 and think the error is #5 now. That would mean the #6 coil was bad. If it was an internal problem with the cyl in the engine the check engine light would come on again still saying error code in #6. If the light doesn't come on then nothing was wrong maybe a random misfiring that meant nothing or something was lose and moving the wires fixed that and I should be happy nothing is actually wrong.

He and the service guy said they can keep it that way with the #6 wire on the #5 coil and the #5 on the #6 coil because the coils in that truck are ALL the same part number. It makes absolutely no difference where on the coils each wire actually goes because they are the same part.

I have been driving it all week and the check engine light has not come back on.

Does this all sound legit?

Could it have been a freak thing and there really is nothing wrong after all if with the switched wires the check engine light did not come on?

And is it OK to just leave the two wires switched on the coil like that or should I make them at least put them back on the coli that matched their number?

I hope what they told me is all true and it must be fine now and they didn't just do something with switching the places of those wires on the coil to trick it so the check engine light simply doesn't come on over this now but should.

Thanks