I have a 2000 xlt. Engine is 5.4 litre with 98k miles. Upon three separate occasions within a 10 month span. I have had to pull the plug over coil off of cylinders #6 and #7 . Due to lack of engine performance as well as OBD telling me of a missfire. I have found a considerable amount of moisture on the POC and in the plug cavities. I removed the moisture with compressed air and reassembled. This has worked up until yesterday. The symptoms quickly reappeared. I checked all heater hoses and hose clamps. I ran the air conditioner to see if any condensation was a problem. With the truck running as well as shut off with engine at optimum temp. I tried to get a look at the intake manifold to find signs of leaking. I checked all intake manifold bolts to make sure they were tight. The coolant level does not appear to have changed. My next move is to change the intake manifold gasket. However I'm open for any suggestions.
Thanks.

 

the moisture may have weakened the coils. when was it last tuned up? was dielectric grease used? what brand plugs? you can get a full set of 8 global or uneek coils on ebay for 80 bucks and less, just type dg508 in the search bar.

 

The moisture issue is my first priority.

 

could have been from anything. could have been driving out in the rain, snow, a leak somewhere. there isnt much to leak on the drivers side to cause issues with #6 and 7 coils. is the coolant resovoir leaking? have you ever washed the engine?

 

Engine is clean and dry. Weather has been warm and sunny.Cylinders #6 and #7 are located on passenger side just below throttle cable linkage adjacent to the battery.As stated there appears to be no measureable amount of coolant lost.

 

Your a little mixed up. - #6 and #7 are on the Drivers side.

- - -Firewall- - -

- - -Bumper- - -

 

Using the above diagram the cylinders I'm having trouble with are #2 and #3.

 

Beat me to it Brew....
I was reading along and was thinking what was on the drivers side that could be leaking and then read he assumed the passanger side had #6 & #7.
Anyways, if the guy changed #2 & #3, but stated that his CEL was showing misfires on #6 & #7, that is a problem in itself.

 

 

do u run coolent in your truck or just water? maybe taste the moisture and see what it is, if it's coolent, you could have a leaky heater hose or a leaky manifold gasket.

 

CEL update. The truck has not shown a missfire code in 48 hours but truck still has hesitation upon acceleration.weather has been warm and dry.

 

probably still have moisture in there

 

I run coolant and water mix at 50\50.

 

so can u get some of that moisture on your finger and lick it to see what it is?

 

Passenger side of throttle body. The elbow that the throttle body bolts to. There should be 3 hoses going into a fitting near the base. One that is perpendicular to the elbow. It comes from the PCV valve. The other two are parallel to the elbow and carry coolant to heat the intake from the PCV hose. If there is a leak in those hoses it could drip down to the Plug wells.