My 2004 ram hemi 4x4 misses on the 7th cylinder and the dodge dealer can't figure out why,. Has anyone had this problem before? When it get up to operating temperature it starts to miss, when the engine is cool, it runs perfect. Any ideas?

 

could be wire heating up, could be a bad plug. I'd start there and if that don't work they can always do a compression test on that cylinder...

 

replace the plug and see if that fixes it...i had the EXACT same problem in my GM with the 5.3 it was just a plug after all.

 

Ok, thank you for the response. The mechanics replaced the spark plugs(2 per cylinder), plug wires, and coil, and the compression checked okay. Diagnostics showed still missing on number 7 cylinder and it runs bad after warming up to operating temp.