[Edgar_in_Indy]

I was able to get genuine Mopar ignition coils at my local Advance Auto for $36 each. (I believe the brand on the box was "Standard", so I was surprised when they seemed to OEM parts). Original on the right, replacement on the left. It's too late to help you, but if anybody else needs to replace their coils, you can save a lot of money that way.

Also, it's a shame they went through the trouble of replacing the front spark plugs without changing out the coils while they had the manifold off. It seems to be a pretty common failure. I had two fail within about a month of each other. Luckily for me, mine were both on the rear bank of cylinders (#1 and then #5) so I could change them myself without much trouble. I went ahead and bought replacements for the three front packs, and when one fails I'll replace all three.

 

[Edgar_in_Indy]

My engine light is on and it reads Code P0303 Cylinder 3 Misfire. Drives rough so I parked it til I can find a mechanic to fix it. Dealer ship cannot even look at it for 2 weeks. Guess I'll try having the same thing done from a friend I know instead of taking it to the dealer ship.

You're lucky, cylinders 1,3, and 5 are the ones not covered by the intake manifold, so it's not necessary to remove it. It's the rear bank of cylinders (closest to the firewall) all the way on the right (towards the driver side) when you're standing in front of the engine.

EDIT: Sorry, cylinder 3 is the middle cylinder. I had a brain fart because the one I replaced on my car was 5...all the way on the right.

It's not too challenging to replace it yourself. You have to remove some miscellaneous stuff out of the way, but nothing too drastic. At the time, I found a YouTube video that helped me. I'll see if I can find it again.

Here's the video I used:

And here's another one that may be useful:

In both the videos, the mechanic is removing the intake manifold to access all the cylinders, but you can ignore those parts if you want and just follow along for the rears.

 

[Edgar_in_Indy]

Well, we had a third coil pack die late last night on my wife's 2017 Limited while still about 30 miles from home.

It started out subtly, while we were on the interstate. The ride felt a bit bumpy at times, and at first I thought there was some kind of surface issue with the pavement in the area. But then I noticed that the "bumpiness" only occurred when I was pressing the accelerator. As we got closer to home, the roughness under acceleration became more pronounced and the check engine light started flashing intermittently and sometimes there would be an audible warning ding.

When we got home, I hooked up my OBD-II scanner dongle and pulled the codes. It showed code P0306, a misfire on cylinder 6,

It looked like I was finally out of luck since cylinder 6 is one of the cylinders hidden under the intake manifold. My two prior ignition pack failures were on cylinders 1 and then 5, which are accessible without removing the intake. Replacing those ignition packs only takes a few minutes, but removing the intake to reach the other cylinders is a bit of an ordeal.

I kind of knew this day was coming, since the two earlier failures had been within a short time of each other (somewhere in the 70,000 mile range). At over 90,000 miles I figured I was running on borrowed time, so I already had four new ignition coil packs on hand, as well as four new iridium spark plugs (I already replaced the spark plugs on cylinders 1 and 5 when I replaced the packs).

Unfortunately the timing was not ideal, since my wife was starting a new job in the morning. I started at around 11:30 last night, and finished up around 4:00 this morning. Not counting test driving the van and putting my tools away, the job probably took 3.5 to 4 hours, including time spent watching YouTube videos for reference, lol. I used the two videos I linked earlier in the thread. Here it is with the manifold off:

The YouTube videos definitely helped, but they glossed over some of the parts I found trickier as an amateur mechanic, such as how to unlock and disconnect the various electrical connectors without breaking them.

Everything went pretty smoothly, except that when I thought I had removed and unbolted everything, I still couldn't pull the manifold completely off because it was hung up somewhere down and on the right. It seemed like there was still a bolt attached, but I couldn't find it. I finally found the following illustration, which showed me the bolt I had missed. It's the bolt labeled "2". It's pretty much impossible to see hidden behind the two big electrical plugs down on the bottom right side of the engine.

Here's the thread where I found that diagram, which has other useful information for the process:

Spark Plug Location?

Where exactly are the spark plugs located on our pacificas? I replaced the air filter yesterday and was kinda looking around for them i didnt see much. 3 might be located back by the firewall? I am afraid someone is going to tell me under the intake and that does not look fun to take off. I am...

www.pacificaforums.com

And here's how my spark plugs looked after 90,000 miles:

I replaced the original Champion Iridium RER8ZWYCB4 plugs with Denso SXU22HCR11S 3461 iridium plugs.

Yeah, it was a bit of a pain doing the repair myself, but I think that anybody who is decently mechanically apt should be able to do it. If I had to do it again it would go much quicker. I imagine a real mechanic would be able to complete the job in under two hours. But I feel good about saving several hundred dollars, and being able to get my wife's van fixed overnight instead of waiting for a repair shop to fit it in.

 

[Edgar_in_Indy]

Not sure what to do now, mechanic has been sitting on my car for 12 days! I've called repeatedly and they say they're backlogged. This morning had another phone call and said he has to do a road test and that the last repair (where they replaced two of the coils) they recommended replacing all of the coils. Would other coils cause a misfire in only one cylinder? I'm about to just take the car back home and try another shop or the dealer.

So I've had three ignition packs fail at different times, and each time I received a code for a misfire on the effected cylinder. So when the pack on cylinder 1 died, I got a code for misfire on cylinder 1. Same for cylinders 5 and then 6. I also experienced identical symptoms each time: Running rough, especially under acceleration, check engine light flashing, and an occasional ding.

 

[Edgar_in_Indy]

Thanks Edgar, based on your experience then would it make sense to just replace the remaining ignition coils?

That what I ended up doing. Especially if you will be removing the intake anyway to get to #2, #4, or #6.

Three of mine failed at between 70,000 and 92,000 miles. I'm not sure if that's typical, or if my van just got a bad batch of packs when it was built, but I had no faith in the remaining packs. I was afraid that the next one would fail at a very inconvenient time. In fact when we took a family trip a couple states away a few months ago, I brought an extra ignition pack and my toolbox along just in case.

Since I was able to find genuine Mopar packs at Advance Auto packaged in "Standard" brand boxes for ~$35 each (see higher up in the thread), I went ahead and bought enough packs to change them all. I don't know if they're still selling repackaged Mopar packs at that price, but I jumped on it.