Hey all…gotta pick your brains once again.
Got a 2001 Grand Caravan (100,000 miles, 3.3L V6 engine) that was setting a CEL - code P0132 (see this thread for more info: http://act…92209.page ). So I followed the advice given and bought plugs/wires, air filter, fuel filter, and the O2 sensor just in case.
The CEL kept disappearing on its own and coming back randomly (never flashing). I didn’t get a chance to put any of the “tune up” parts on…my wife was driving the van to my parents place and as she got into the driveway the van started misfiring and shaking and the CEL came on, flashing. She shut down the van right away and called me.
Well I brought all the parts over and thought I’d change those first to see if that would help. I pulled the codes just to see what they were: P0300 (random/multiple cylinder misfire), P0302 (Cylinder 2 misfire detected), P0305 (Cylinder 5 misfire detected), and P0352 (Ignition coil B primary/secondary circuit malfunction).
I got the front 3 plugs/wires done, air filter, but I could not figure out how to get to the rear 3 plugs and I could see the O2 sensor but again, no way to get to it. The van was still running rough and CEL flashing so I shut it back down and got it towed to the mechanic.
Explained the situation to him, gave him the remaining 3 plugs/wires and O2 sensor to put on and asked him to figure out the real problem. We had an issue about a year ago with the same symptoms (didn’t have a code reader back then so unsure of the codes) and it was fixed after an hour of labor. He said at the time that some wires that go to the fuel injectors had melted and were replaced. Van has been fine since then, until recently.
Soooo after a $600 bill this time around to fix the problem (and do the other items), he states that more wires had melted but in a different area this time…wires that go from the O2 sensor (front) and to some other components.
The van was fine for 2 days and then the same problem came back: after driving long enough to getting the van to operating temp, if you stop and restart it before it’s completely cooled down, it’ll always start no problem, but then run rough for about 10-20 seconds, feels like it’s misfiring or backfiring and it won’t move…no CEL this time, and it smooths out on it’s own after waiting it out and pressing on the accelerator a bit (which can’t/won’t force the RPMs up during this issue…the RPMs kinda have a mind of their own, up and down around 1,000 until it clears up the problem then roars to life and it fine for the rest of the trip).
Took it back and mechanic now says it’s those darn wires again, they are in a bad spot near the front bumper at the bottom of the engine and he wants to replace the whole wiring harness. Says the dealer wants $1800 for the harness, but will try to get one from a junkyard for $150 and won’t charge for the labor to put it in.
My confidence in this mechanic is pretty much gone now…any comments on all of the above? Any suggestions would be helpful…I know this is a tough one to diagnose especially on the Internet.
Thanks in advance…
Jad
Wow that was a long post…sorry!! and thanks for reading it, if you did 
Dear Driving Me Crazy, Have you thought of taking up a hobby-------maybe, Ming Dynasty stamp collecting, or South American butterfly trading?
Oh, the van! I’m with you. I have to wonder how wires can keep “burning”! Since none of us here, in cyberspace, can actually examine the van, you could have a qualified mechanic to examine it. He may see something the other mechanic is overlooking.
I suspect “burning wires” is the mechanic’s shorthand for something else, perhaps shorted or frayed? Wires can become frayed, ie, lose insulation, or have the insulation crack, which can lead to shorts, or they can open, which means the conductor breaks. I guess a wire could develop a short to ground and overheat (burn) due to the short circuit current, but a fuse should blow to prevent that.
The only way many wires can become burned (IMHO) is if some external cause burns them, ie if oil drips on a harness and then gets ignited, you could have burned wires. In any case I’d switch mechanic also, you are not getting a straight story from him.
by any chance have you removed the heat shields from the exhaust manifolds on the front of the engine? it sounds like they may be gone, or knocked off.
just to let you know, i have to do my back 3 plugs ‘blind’ over the top of the valve cover, using a 8" extension, and a short ratchet.
for next time:
the O2 sensor can be gotten by putting the van up on ramps, and sliding under from the front, and using an open O2 socket with the side lobe hole for the extension. you get the breaker bar and put the extension on the socket backwards so the breaker bar is down under the car with you. (you only get about 1/16 of a turn, but it is enough to ‘break’ the o2 sensor loose. you can get the rest from the top, with a little perserverance.) actually i had more of a bugger of a time getting the little clip loose from the wiring harness on the left side of the frame than the actual O2 sensor. (this seems like a two handed job, but there is only room for one hand in there!)
in regards to your original problem, i have seen this sputtering on my van once or twice, but changing the plugs and wires (and NOT the super platinum split fire crap) seems to have fixed mine.