Adventures with bad ignition coils...

D

Dynamo

Member
Location
Austin, TX
As I previously posted, I got a code P0300 and P0304 while out driving yesterday. I parked it and left my FX35 at my parent's house.

I go to the dealer today to get a new coil for cylinder #4 as assumed that's what was wrong. The dealer had 2 in stock but I only bought one. As it turns out I should have bought both of them. I replaced the #4 coil this evening after work and start it up but it still is vibrating and not running great. So I hook up my dad's code reader and now I get a code P0302 (misfire on #2). Just lovely.

Since the dealer was closed by that time I decide to try the local parts stores to see if they have anything thinking. Advance Auto has a couple in stock so I run down there to get one. The ones they have are a brand called Original Engine Management and it looks EXACTLY like the real deal OEM coil that I brought with me. All the same stampings and markings, I literally couldn't tell them apart. However there seemed to be some dirt on it in a few crevices so I am wondering if it is a recycled part or something. Anyway, I didn't care at that point as I plan to replace it and the remaining 4 and the aftermarket coil with new OEM coils when I change the plugs because I don't want to break down somewhere due to another bad coil.

I get the coil from Advance in there and it fires right up and definitely sounds and feels a-ok. No more codes either. I drove it home without any problems.

In case anyone is interested, both bad coils physically looked bad. In the picture below, the bad coil is on the right and the new (Infiniti OEM) good coil on the left. You can see on the bad coil where it is slightly melted and swollen next to the plug where the wiring harness connects. Both bad coils looked like that. Before I ran to Advance Auto I felt all of the other coils for that defect and all were ok. If you ever have a bad coil I would suggest feeling the others just in case.

FX35_coils.jpg
 
Cool, I had a VQ35DE in my QX4 and the ignition coils were a known issue that they needed replacing after X miles.
 
Damn! I had another coil go bad at lunch today. I managed to limp it back to work as I was almost there.

To complicate things even more, NOBODY has any. I have called all Nissan and Infiniti dealers in the area and all are out. Looks like I can get 3 more from 2 different Advance Auto stores at the moment so I am going to go grab them while I can.

A word to the wise: if you have a coil go bad, replace them all if you can.

Infinitipartsusa.com doesn't even have any in stock. :(
 
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Interesting update...

I found a related service bulletin, ITB11-017. Describes the coils blistering/melting and having misfires, exactly what I have been experiencing.

The solution is to replace a steering member bolt underneath the glove box, replace the battery to body ground cable and bolts, replace the body to engine ground cable and bolts, and clean up a couple of ground points. Easy enough to do.

Here's the kicker... I had my dealer replace my dash week before last and all of the sudden I am having coil issues and the service bulleting specifically mentions a bolt underneath the instrument panel (passenger side). I wonder if this was a bolt that had to be removed to replace the dash and I wonder if it got left out or not tightened. I don't want to jump to conclusions and blame the dealer but it seems like a strange coincedence to me. I am going to remove the glove box tomorrow and see if I can find that bolt. Everything else is in the engine bay and it doesn't look like it was touched (no reason to).

The fact that I have had to replace the same coil twice now tells me something else is causing the coils to fail.
 
Where did you find this info? I just had my dash replaced too. I was thinking of adding the grounding kit. i wonder if this will help me from not having the problem your having?
 
Huntsober said:
Where did you find this info? I just had my dash replaced too. I was thinking of adding the grounding kit. i wonder if this will help me from not having the problem your having?
Click to expand...

I found the service bulletin over at infinitihelp.com. I don't know if an aftermarket grounding kit would help but it does sound like a grounding issue is causing them to fail.

---------- Post added at 09:38 AM ---------- Previous post was at 09:34 AM ----------
GOFAST24 said:
Jsut curious, what was the price of the OEM coil vs. the Advance Auto Parts coil?
Click to expand...

The OEM coil from my dealer was $128.99. Infinitipartsusa.com say the MSRP for them is $107 but their price is $80.25. The Advance Auto coil was $79.99.

---------- Post added at 03:01 PM ---------- Previous post was at 09:38 AM ----------

I don't have an of the new pars called for in the service bulletin but I did clean up all of the connections. The bolt underneath the dash looks like it would not have been touched by replacing the dash so I don't think the dealer had anything to do with the issue.
 
I've had 2 coils go bad on me on two separate occassions in the past year, both times towed to the dealer since I'm under an extended warranty. the first time, the replaced 2 coils and said they re-grounded the others. This last time, I saw in the paperwork that it said "TSB applies". Hopefully this fixes the issue, whatever the reason is.

Are the coil packs easy to replace by yourself? I only have less than one year left on the ext warranty so if it happens again, I'm on my own.

Also, whenever your coil packs went out, did it damage your catalytic converter at all? Both times mine went out, the dealer replaced the coil packs, I pick up the car, and within a couple days I would get a SES light. Dealer said when the coils shorted, the engine was dumping fuel directly to the cat which damaged it.
 
KNFX said:
I've had 2 coils go bad on me on two separate occassions in the past year, both times towed to the dealer since I'm under an extended warranty. the first time, the replaced 2 coils and said they re-grounded the others. This last time, I saw in the paperwork that it said "TSB applies". Hopefully this fixes the issue, whatever the reason is.

Are the coil packs easy to replace by yourself? I only have less than one year left on the ext warranty so if it happens again, I'm on my own.

Also, whenever your coil packs went out, did it damage your catalytic converter at all? Both times mine went out, the dealer replaced the coil packs, I pick up the car, and within a couple days I would get a SES light. Dealer said when the coils shorted, the engine was dumping fuel directly to the cat which damaged it.
Click to expand...

The coils are pretty easy to replace. Basically like changing spark plugs without changing the spark plugs. There's a DIY about how to change spark plugs, I just followed it for the coils. Remove the engine cover and intake snorkle and you can get to them all. Only one bolt and one electrical plug for each. The only thing that makes it remotely difficult is all of the wiring harnesses in the way but it isn't too hard to work around them.

As for the catalytic converter, I have an appointment to take my FX in tomorrow because I now have a SES light for "P0430 - catalyst efficiency below threshold (bank 2)" which I am guessing means that possibly the bank 2 converter has gone bad from the bad coil(s) & misfiring. If it is bad then I am *hoping* they will cover it under the 8yr/80K mile emissions warranty as otherwise I will have to pay for it. I am prepared to pay for it but it would be nice to not have to.

The codes for the bad coils have been erased but I am going to take in the bad coils to show them plus a printout of the TSB and discuss the situation and course of action. I was going to get the new battery cables and bolts today and do the TSB myself tonight but they don't have the parts in stock so I guess I will let them do it. If they don't do it then I am going to do it myself afterwards.
 
They replaced my cats under the emissions warranty both times mine threw a code, so it should be no cost to you either.
 
You would think that if the computer knew the coil on #2 was bad that it would also stop injecting fuel to number 2 cyl to prevent having to change out a expensive cat under warranty?
?
KNFX said:
I've had 2 coils go bad on me on two separate occassions in the past year, both times towed to the dealer since I'm under an extended warranty. the first time, the replaced 2 coils and said they re-grounded the others. This last time, I saw in the paperwork that it said "TSB applies". Hopefully this fixes the issue, whatever the reason is.

Are the coil packs easy to replace by yourself? I only have less than one year left on the ext warranty so if it happens again, I'm on my own.

Also, whenever your coil packs went out, did it damage your catalytic converter at all? Both times mine went out, the dealer replaced the coil packs, I pick up the car, and within a couple days I would get a SES light. Dealer said when the coils shorted, the engine was dumping fuel directly to the cat which damaged it.
Click to expand...
 
KNFX said:
They replaced my cats under the emissions warranty both times mine threw a code, so it should be no cost to you either.
Click to expand...

I dropped my FX off at the dealer this mroning and had an interesting conversation with the service writer and tech who will be working on it. The tech said that it is a grounding issue and that there are a couple of more ground spots to check in addition to what the TSB describes. He said I will just keep blowing coils until the grounding is fixed. He said the coils should be replaced as a complete set so I am going to have them replace them all while they are in there.

As for the cats the tech said both should be replaced even though I only have a code for one side. He said most likely it was just a matter of time before the other side would need to be replaced. The good news is that both cats will be replaced under the 8yr/80k mile emissions warranty. I was really worried that I would have to pay for those since the code for the bad cat appeared after the coils went bad.

So all in all I'm not happy that I will be paying for new coils but very happy that I will be getting new catalytic converters under warranty.
 
Dynamo said:
I dropped my FX off at the dealer this mroning and had an interesting conversation with the service writer and tech who will be working on it. The tech said that it is a grounding issue and that there are a couple of more ground spots to check in addition to what the TSB describes. He said I will just keep blowing coils until the grounding is fixed. He said the coils should be replaced as a complete set so I am going to have them replace them all while they are in there.

As for the cats the tech said both should be replaced even though I only have a code for one side. He said most likely it was just a matter of time before the other side would need to be replaced. The good news is that both cats will be replaced under the 8yr/80k mile emissions warranty. I was really worried that I would have to pay for those since the code for the bad cat appeared after the coils went bad.

So all in all I'm not happy that I will be paying for new coils but very happy that I will be getting new catalytic converters under warranty.
Click to expand...

Wow, good info here. Thanks for sharing.
 
KNFX said:
He didn't happen to mention where the other ground spots were did he?
Click to expand...

He mentioned that there is a brace that runs underneath the dash and it sounded like there were a couple of places along it. If I talk to him again I will ask. I have a feeling though that they will only do what the TSB calls for as otherwise they would have to remove the dash. He did seem familiar with the overall problem and knew there were grounds that had to be cleaned up.
 
That just makes me scared that I will be replacing coil packs and cats from now on. Hopefully the tsb addresses enough to keep this from happening again. I wonder if this is a result of having to replace the dashboard...
 
KNFX said:
That just makes me scared that I will be replacing coil packs and cats from now on. Hopefully the tsb addresses enough to keep this from happening again. I wonder if this is a result of having to replace the dashboard...
Click to expand...

Unless they just left or removed some bolts under the dash that should be there then I doubt having my dash replaced was the cause. At this point I think it is just a coincedence. The grounds in the engine compartment are much more susceptible to water and the elements that might cause corrosion.

Depending on the age & mileage of your FX I think doing the TSB yourself would be good preventative maintenance. Each cable is ~$40 and the 5 bolts should be less than $10 so altogether less than $100. The two cables are very easy to replace and the bolt under the dash is easy to get to when you remove the glovebox as if you were replacing the cabin filter. Had I known this was an issue 2 weeks ago I would've done it myself and saved some money. Oh well, at least I am getting new cats out of the whole ordeal.
 
Got my FX back yesterday. New cats, new coils, new spark plugs, and new battery cables. It's running good and no more SES light or other problems.

I didn't get a chance to speak to the tech again, sorry.
 
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