I recently had my head gasket replaced at the dealership (almost a month ago), and now I am running into another odd issue with my car. It seems to be misfiring at random, and has gotten progressively worse.

I had originally thought that it was a bad coil pack, so I replaced the one that was not firing. It had gotten a bit better, but as time went on, it was getting a little sluggish. Yesterday, I replaced the other three coilpacks, and all seemed fine. Last night on the way home, my car would not accelerate, and was misfiring bad. I pulled over, turned the car off, then back on, and it was still misfiring. I opened the hood, popped all 4 coil packs off while the car was running, (one at a time) and it fixed the issue. I have a code reader, and read codes P0352 and P0302 (both of which i looked up, IGNITION SIGNAL COIL B FAULT and Cylinder 2 misfire)

Today, I went for a run at the lake. On the way back, it started happening again. Instead of pulling all the coil packs, I just unplugged the 2nd one, and it resolved the issue. Again, once I pulled into my development at home, it started happening again. This time I pulled the 3rd coil pack, and that resolved the issue. Later, I checked the spark plugs. They are old, and will need to be replaced, in fact that is on my to do list for tomorrow. I swapped the 1st and 2nd spark plug, took it for a spin, and when it happened again, I pulled the 1st coil pack, and the issue stopped.

When it is not erroring out, I can notice a small loss in power, but it is in no way completely undrivable. It's only the random times that it decides to make me pull a coil pack then plug it back in. I have searched, but wasn't able to find any information other than what the P0352 code means. Does anyone have a clue as to what is happening? My wallet can't take a 5th trip to the dealership.

 

Ok, so if I recall correctly the P0352 is a coilpack missfire, multiple, so the only thing tha corresponds with all the coilpacks is the coil harness, if it happens that everytime you disconnect the pack the problem stops, then it starts when you drive a bit more chances are the harness is shorting somewhere on the engine or against itself. Try looking at that physically, that's about the only way you can see it, also the plugs could be a possibility, I would change them. Also make sure you had the coilpack recall performed on your car, so you don't have any bad experiences due to outdated packs.

 

On the drive into work this morning, everything ran relatively fine. I still noticed a small power loss and mpg, but i didn't have to pull over. Since i left early, and got in early, I took a quick look at the harness, but i am not sure exactly what I am looking for. At a quick glance, everything looked normal. If it makes a difference, I don't disconnect the harness from the coil pack, I pull out the coil pack from the cylinder.

 

The I lean towards this; when you move the harness it could reset whatever the short is. If you can't find it then is probably something else.

But here's what you're looking for anyways when you look at the harness: Frayed wires, insulation missig a little chunk, small knicks on the wires, the ground loose or not making full contact. Just follow the harness on its entirety from the last pack to the first one with a flashlight, then from the first one you might need an inspection mirror to look underneath the pack of wires going to the ECU, one or more little wires divert towards the firewall for grounding.

 

Awesome Dan. I did check, and some of the wires on the 2nd cylinder were frayed. I wrapped them in some electrical tape, and it did help out a lot. It's not throwing the P0352 code, but i can still feel a power loss. I think I am just going to go out and get another set of wires.