My engine recently misfired a lot. I had it checked out at the dealer, for $80. Then the mechanic and manager tried to talk me into replacing all ignition coils, whether bad or not. Their theory was some one after another failure crap and I didn't buy their story and drove back.

In addition, their price was an astounding $90 a piece and they try to let me believe that labor cost would be huge if I just replaced them one at a time. I happened to replaced spark plugs months ago and I knew how easy that job was. Later I found that I could just pay $60 per piece if I ordered from online dealers. Were they trying to rip me off? I probably would have listened to them but for Max.org. I know there are some experts who are not biased by interests.

Any opinion is welcome.

 

If its a 99, I'd say replace them all. My 3rd coil pack in 30 days just started going out. Wish I'd replace them all the first time. Courtesy Nissan has them for about $54 a piece.

 

Read the stickies above on how to check codes yourself. That will tell you which one is bad, then replace yourself as needed. Very easy.

I had one go bad (#6) in my 99 almost 10k miles ago and that's it. Ordered from DAVEB at South Point Nissan for like $55-60/ea. And since 99's tend to eat up coils more than others, I just went ahead and ordered two more (one front bank, one rear bank) so that I have them handy if/when another one goes bad.

Do not take your car to Nissan for this unless you don't mind paying $300 for something you can do for $55-60 yourself. And I don't buy the "one after the other" theory either.

 

Mine is a 95. If all need to be replaced once one goes bad, why didn't Nissan make them all into one piece to cut down on the cost?

 

The bad one (#1) is not acting up enough to trigger a ECU code.

 

NO NO NO! Under no circumstances replace all 6 ignition coils! WTF are you talking about man??

Anyway, misfires you say ehhh? Well, it's like this with defective ignition coil(s) - ...I had a defective ignition coil with 3k to 5k RPM range hesitations. At first, I was frustrated because no check-engine light came on, therefore making the self-diagnosis extremely difficult if not nearly impossible! I drove around with the hesitations for about 4 months. Eventually the defective coil will wear out to a point where the hesitation is no longer such, but instead, a big pause. When that happens, the coil will cause severe cylinder misfire, causing you ECU to throw a code - which was exactly what happened with me. I check the code and indeed IT WAS cylinder #5 misfire. After that, I decided to play detective and swapped Ignition coil #5 (yes, the one on cylinder #5...they correspond) with coil #1. I reset my ecu, drove around for some time and got a check-engine again with...yes, u guessed it, cylinder #1 misfire this time. At this point, it was obvious that what cause the hesitations was an ignition coil going bad. I bought a new coil at a local nissan dealer for $75 and replaced the defective one. OMG...UNLEASH THE POWER! Jesus, what a difference!

- when looking at your Maxima's engine compartment from the front the cylinders are as follows:

1 3 5

2 4 6


Since the coils for the back (1,3,5) cylinders (...the ones closer to the windshield) are different than for the front cylinders (2,4,6), you can only swap front with front and back with back: (e.g. swap 5 with 1 like I did, but cannot swap 5 with 2 for instance)

Moreover, I just want you to know that it is a very complicated process. The only way to test ignition coils (and you have to test each one of the six) is to use some kind of device that mostly only auto mechanics own. It's not your regular multimeters etc., it's a more complicated device I forgot what it is called. The reason is because you know that a LOT of spark and hence electricity goes through the coil. So multimeter and other devices are not strong enough to transmit so much electricity.

Also, a defective coil will still transmit say a spark or any other current of electricity under certain voltage without a problem. Yes, it is only under heavy voltage (like when accelerating in a Maxima) it will lose half of what it is transmitting at the top (...you know how a coil looks I assume) either because 1) it shorts to the valve body of the engine because cut/worn out rubber hence poor insulation of the coil or 2) the top part of the coil (looks like a cube basically) is defective inside somehow. I had case 2 because the rubber was in excellent condition. So if it is case 1 you can find out which coil it is just by closely examining it by yourself, without having to test it.

Another alternative to testing the coils (I went with this) is to drive hard for a couple of weeks. It worked for me. A defective coils (case 2) gets more and more defective the more you drive. However, it gets even more defective under heavy load (heavy acceleration) like say WOT. Well, after a couple weeks of hard driving my coil was so weak and defective that it eventually caused the cylinder to misfire SO much that it finally made the ECU throw a code. Remember that a slightly defective coil will ALMOST NEVER throw a code. Anyway, when I checked the code it said "cylinder 5 misfire" so I knew right away it was ignition coil # 5. Called some 7 Nissan dealers and found one cheapest for $75. (yes, they are expensive!)

Lastly, 99.99999999999999999% of time, only 1 ignition coil is defective at a time. It almost never happens that two or more ignition coils are defective at once.

Hope this helps and clears up some things.

 

BOSS is right, a coil going bad won't trigger any codes, until the cylinder actually starts to misfire. You may just obtain some driveability and performance issues, get the codes checked at a local auto parts store that lends out OBDII scanners, and replace the coils on whichever cylinder has the misfires. If the driveability problems persist even after you replace the bad ones, you may have to play a little musical chairs to find the one thats about to go bad.

TK

PS It never hurts to have a couple extra working ignition coils laying around, in case new problems arise in the future.

 

Let me further explain my coil pack experience with our 99. We had an intermittment misfire under load and at idle for months. Finally it got to the point a code was triggered. (#2) Replaced coil pack and all was fine for about 2 weeks. Then the misfire started again. After about a week, code was triggered (#1). Replaced coil all was fine again. Now 3 weeks later, misfire is back. Another code was triggered, this time #5. In all three cases, I've switched the coil packs to another cylinder and then verified the coil was bad by triggering a new misfire code for that cylinder. With 3 coil packs going bad in a relatively short period of time is why I suggested replacing them all on a 99. Its common knowledge here, the 99's have problems with the coils. I'm tired of the misfires and time spent switching coil packs and then obtaining codes. Thus, I 've decided to replace the remaining coils with new ones.

With your car being a 95, I would then suggest just replacing the one faulty coil. You most likely will not go through the problems I had with our 99.