We changed our plugs couple of months ago, old ones looked very good, no difference with new ones. Now a #6 misfire code is shown. I just learned the info about the possible vacuum leak around the throttle shaft. If we have this problem too could it cause the misfire code to happen too ? Or just a coincidence by chance ? Thanks. *BW*

 

? ? ? Maybe no one understands the question ? *BW*

 

Well, I'm not that familiar with the 3.5 motor BUT...

Have you rechecked the plugs for signs of "fouling"/damage
Have you checked/tested the coil/plug wires
A misfire code can also be set by a malfunctioning fuel injector
With the computer management of these motors of now, a vacuum leak would generally set a code of it's own
How are you getting codes from the computer? A scanner that can also perform LIVE DATA READING can help greatly to track down the cause of the problem.

 

Thanks Rebel. Others must have had this problem too. Basic scanner said #6 misfire. Will probably get a new coil assy soon. Too bad it is under the intake manifold. Thanks again. *BW*

 

Make sure that there is not even just a couple of drops of water in the spark plug well.
If there is any, the water ionizes and creates a short that shorts out the plug.
wipe it dry, and spray a little WD40 in it and then try starting it.

 

Also, if you did not use the plugs recommended by Chrysler, they can and will start failing in just a few months.
I had both the water, and the issue with plugs that were compatible according to the parts store issues.
I found out on another forum that the 3.5 will eat up any plugs other than the ones recommended by Chrysler.
The Chrysler recommended plugs are more expensive, but they work very well, and last a long time.

 

Thanks Bill, we used NGK ZFR5LP-13G Platinum. Probably just removing the coils and boots was enough to disturb something. Water ? I don't think so but worth a look when the coil/boot is removed. Thanks for the reply. *BW*

 

Intake off, coil out, NO water, plug looks normal. First step, changed all plug-coil boots, batt disconnected, NO more dash code. Took for license insp, egr/evap NOT ready. Drove 100 miles. Next day same thing for insp, drove 50 more miles, added 1 small bottle of Techron, with some spirited style driving and parked for the night. Made sure the gas cap O ring had lube on it. Next day a full warm up and passed insp ok. Am concerned that so many elect plastic connector plugs and lock tabs are in such bad shape. Any reasonable fix other than a new harness ? Tks to all. *BW*