2003 Ford Expedition Misfire and coolant issue

[Carl Vosen]

What’s up everyone, New to the forum here and could really use some advice, recently I purchased a 2003 Ford Expedition with a 5.4 triton. The truck was misfiring on cylinder 7 went ahead and replaced it truck ran great for a few days then started misfiring on cylinder 4 i replaced the coil pack on cylinder 4 and the bolt was a little bit of a nightmare to get to. Finally replaced the coil on 4 and it was still throwing the code pulled the plug plug looks fine. Now I’m noticing the trucks leaking coolant I can’t tell from where but it looks like it’s dripping onto the ground right near the transmission bell housing obviously I have no heat and it will randomly stop missing then start missing again and it’s constant on cylinder 4. I’m pretty concerned I have a serious issue going on but I’m also thinking I could of broke or knocked a coolant hose loose near the heater core trying to get the bolt off coil number 4. Any advice and help would be GREATLY appreciated this is driving me absolutely insane. Thank You

 

[91fox]

Hi, the best thing to do is obviously check to see if you knocked any hoses loose. The heater valve is a notorious leak on most Ford's with the 4.6/5.4. it also could possibly be your intake manifold gaskets... Where the boots dry when you removed them? When the gaskets leak, the coolant tends to go into the spark plugs holes.

 

[docraymund]

Check the coolant leak one early morning with a strong flashlight it might be one of the hoses near the firewall. As for the #4 cylinder, either the female connectors on cop and fuel injector may be loose. Try carefully bending the male tab slightly to one side to ensure good contact.

 

[Don Hall]

May help (?):

https://axleaddict.com/auto-repair/Engine-Misfires-Diagnosis-Tips-and-Strategies

 

[GAINMOB]

how many miles...this will happen with 100/200K maintenance intervals for cops and plugs...just happened to me and changed all the plugs and coilover packs...running smooth again