My 04 Hemi Durango starts to miss when ever it is driven in moderate to heavy rain no check engine light or code is set runs perfect when in dry weather it just started doing this a month ago. I sprayed coils and wires with marine wire dryer and seal plugs are new Bosch +4 Platinum just changed also any ideas would be appreciated. It has never quit just misses

 

You won't find many +4 fans here. While that isn't necessarily your problem, they aren't any good for you in the long run.

Check the coils closest to the intake for contamination from water splash via road spray and rain coming through the grille area on that side.

IndyDurango

 

AndyZ

How many miles on your D? Being an 04, the wires are at least 7 years old and have spent a lot of long, hot hours under the hood of your D.

When this happens, it would help to get to a dark place and open the hood to see if you can see any signs of the spark voltage shorting to ground.

Don

 

It has about 109000 miles. I replaced it with the Bosch +4's after I started having the issues. I never replaced the wires but they all are sparking, are not corroded and did not see any fraying on the wires. I did see other post and complaints to the nhtsa and one said IAC sensor went bad and another said that water was getting in through the cowl. I checked the coils and they are ok.

I don't see the cowl being the cause. The seal is in good condition. Checked for faults after the rain we just had and it is showing a code P0300, which is a universal code for random misfire.

 

had this issue with my '04...replaced plugs and wires, no help. a few months later a valve spring broke and had to have the headers rebuilt, that fixed it. I know, not much help.

 

Good seals with the wires/coils? Dielectric coating on top of the plugs maybe help?

 

ON second thought I might just go ahead and replace the wires. At least you would eliminate a potential answer to the problem and what would seem like an obvious first thing to fix if you took it to a mechanic.

 

Same problem, I am replacing the wires and COP boots. (04, LTD, 5.7L, 2WD)

I have also read about adding a piece of flashing to the cowl and/or replacing the cowl weather stripping to protect the plugs from water splash, but I haven't seen any pictures to DIY. Does anyone have a recommendation where to put this?

 

I would like to know where the spark trigger mechanism is located possibly watter is getting into that unit putting up splash guards is not really solving the problem as I had the factory one by the radiator gone before the truck was a week old and this problem just started this year

 

I opened the hood and dumped ~a gallon of water on the windshield. To my surprise, I discovered the cowl is actually partially separated from the windshield and water pours through that onto the plugs/coils for the 3,4,5,6 cylinders. Also, apparently there is a new/replacement part for the cowl from Dodge to fix this.

I'm going to silicon the cowl to the windshield and make my own water guards to fit around the passenger side wiper shafts (since there are two).


Otherwise, each coil is mounted on a plug and has a plug wire to another cylinder. The coils get their commands to fire from the PCM (powertain control module), through a connector. I suppose you could check that the connector/coils are not getting water logged, being that they are male-in-female, I doubt that is the problem. If you're going to that length you might as well add a some extra di-electric/water resistant grease to those connections.