Hello,

First time poster.

2003 Grand Caravan 3.3 150k miles. Rough idle and hesitation/vibration at all speeds. Clearly, a cylinder or 2 is being dragged along for the ride.

Local parts store ran codes, got the following:

P0300 (multi cylinder misfire)
P0302 (Cylinder 2 misfire)
P0304 (Cylinder 4 misfire)

The plugs and wire are 20k miles old.

I took a gamble and replaced the coil. No change and codes returned.

THANKS in advance for advice on next steps!!!

 

I failed to add that I pulled plugs #2 and #4 and they appeared typical. I grounded them against the block and observed healthy spark on both.

 

Unbolt the power steering reservoir and lift it up (no need to disconnect either hose). Remove the covering on the injector wiring harness which runs under the reservoir and inspect each wire carefully for melted insulation. Melted wires in that location is very common on the early gen 4 vans.

 

Hi, just a follow-up to this thread.


Compression test revealed little compression in cylinder 6.


Exhaust valve was stuck just slightly open, and obviously "burnt". I pulled a head from a junkyard vehicle and installed. Gasket set was killer expensive ($175), but this being an old-school pushrod engine AND the fact that the problem was on the cylinder bank easily accessible made this about the easiest head removal I've ever done.


Fixed and drove the car 500 miles back home from where it was stranded. No problems so far.


Thanks

 

Interesting that the specific misfire codes were for cylinders that were ok, and no P0306 was set. Not the first time I've seen someone post that the wrong cylinder misfire codes were showing up. Glad you got it fixed and thank you for posting this follow up (most never do).