first off this not my truck i am asking about it's my dads, he has a 2002 f150 xlt 4x4 5.4L and he replaces the coil packs all the time is there a way to prevent these from failing so often, and is there an easy way to get to the spark plug on the very back on the passenger side?

 

Be happy to offer some insight but how was it determined the coils needed to be changed so often?
We need to establish some reason in order to look at an improved outcome.
On coil install, the boot tips need to be lubed just inside and on the ends so the boot 'finds' the spark plug top because you cannot see to do it.
A light sensitive feel as the boot slides onto the plug is needed and how well the coil sets in place without being forced.
There is spring inside the boot that must set onto the plug end.
Make sure it's not jammed up inside the boot and down level with the boot tip.
These little things are important or you get a hassle that confuses you just on the basis of the coil was changed and should be all good when it may not be.
Then there is a matter of moisture getting into a plug well.
It's easy for liquid to get in but once in can't get out very easy and changes phase with heat and back to liquid again as the motor cools. It's conductive either way.
Good luck.

 

he replaces them a bout once a year sometimes every two years, he has a plug in reader that said the packs were bad.
i think the reason they go bad is his truck sits where water drips on the hood every time it rains, and we get a lot of humidity here.
we actually got that plug out today, the heater core had leaked months ago( heater core has been replaced) and corroded the plug in the hole.
i was told by a friend if you put silicone on the coil pack where it sits in the head it'll seal it up is this a good idea?

 

I personally would not do it, is it misfiring,or going off reader, is it telling all cop's are bad at the same time? or one at a time, , keep a spare in truck and change the one that goes out, and silicone I wouldn't, if you have to change them could be a lot harder , then worry about pieces of silicone falling in plug hole if you pull plug, is he using good cop's or cheap ones? water dripping on hood should be no issue, does the truck sit a lot,? or get driven regularly? some one else will chime in I'm sure, my 2 cents,good luck

 

I'm not trying to be difficult but the way you describe what he does is just plain silly to work that way.
No reader tells if anything in faulty without doing tests to determine the needs.
Changing parts en-mass just invites more trouble to the point confusion reigns.
Then the fall back is all the parts are new, what now?.
It doesn't mean anything. the fault is still there.
Pin point the trouble, do the repairs and know what it was all about.
Otherwise the same issues occur over and over again and wonder why.
There is an old saying that goes like this.....Do what you always did and you get what you always got!
Moral of that is, change the way things are done for a better outcome.
At this point it's nice to try and help him but he likely won't do anything different than what he has done in the past. Refer to the saying above..
Good luck.

 

Someone here do not google. It is not coil pack then sit of coil pack is rusty. I didn't replace coil pack never. Did sand steel where coil pack sit and put dielectric grease. LOL.

 

100% agree.

 

the reader tells which one is bad and when we pull the one it said was bad they are rusty and junked up, he drives it everyday.
so i don't really know.

 

Question bluegrass, should you put a small bead of dielectric grease in the center of the spring? Will this hurt anything? Just curious?

 

Lets go over some dynamics of coils:
1. They are an electromagnetic device meaning power is applied to the coil winding to build a magnetic field around it's core.
2. The 'removal' of power at the time for sparking the cylinder creates the high voltage at that time due to the collapse of that magnetic field.
3. Winding resistance means very little as long at it is reasonable and not too high or to low. Measuring resistance has very little value in determining the suitability of a coil.
4. The computer program measures the crank rotation time every time to determine the cylinder's contribution to the overall power at the crank.
It does not indicate any specific cause of misfire because it could be the coil, the plug, cylinder mechanicals or a loss of fuel injected to that cylinder.
5. A special fault case is a coil with 'shorted turns'. It is not a hard fault since the coil still is able to spark the cylinder under normal air/fuel ratios.
The issue arises when the EGR system is called to open during OD and low throttle applications.
At this time the air/fuel ratios go very lean by design.
This require the coils' full high voltage capability be present or misfire occurs as a stumble like reaction until down shift occurs to exit that drive situation.
This is **not** a transmission fault.
When it clears, it's due to the A/F ratio has richened up and requires less coil voltage. Under this condition the misfire record that is normally kept is 'cancelled' so no code Id set.
The issue with the coil is a shorted turn or turns limit the magnetic field that is generated thus the max voltage generated at collapse.
You cannot measure for shorted turns with any normal Ohm meter due to the very low resistance involved creating a unreliable measurement..
.
Once this type of operation is recognized as a clue, the use of a Scanner not a Reader is needed to look at a different misfire record location for the source of the misfires.
That location in 97 to 04 systems is Mode 6, Test 53.
At this location is the misfire records for all cylinders.
Any cylinder that exceeds a high limit will be the cylinder that very likely need a coil replacement. You may even see other cylinders that need attention soon.
Please remember that normal misfire codes are hard faults as described above.
A open coil, open connector, faulty spark plug or wire will be a hard fault and do not normally benefit from resistance measurement if one will be observant of the effects seen.
As you should see from above, a code does not tell what parts to replace even though one or more may actually be in fault in the final analysis and outcome.
Trust the system to register the fault then use the proper procedure to detect it. The system virtually never makes a mistake.
The 30x codes are secondary codes for coils, boots, plugs and fuel and cylinder mechanics.
The 35X are primary codes for open coil primary side all the way back to the PCM including the harness and the PCM coil drivers.
No resistance measurements needed to Id the cylinder involved but there is a resistance measurement if the PCM coil driver is suspect as the only way that fault may be simply determined from the outside world.
.
Dielectric grease application:
This material is for two purposes.
1. As a guide for the boot to 'find' the spark plug tip when installing the coil so it slides down on the plug tip.
2. As a poor excuse for a water seal or high voltage control.
3. As a help on allowing the boot to release from the plug at removal time.
Otherwise the effectiveness of the grease is largely lost after a few drive cycles because it hardens up and become somewhat brittle and disappears due to heat.
Good luck.

 

nice write up Bluegrass,,will save

 

Thanks bluegrass.

 

yes a leaky heater hose at the core will really screw with coils on the passenger side and so will a leaking intake.
I've also pulled out coils with oil down in the hole, no idea why as replacing them with plenty of dielectric grease seemed to fix the problem.
what you want to use is dielectric grease, squirt a little right in each plug boot. I have also used the same on the outside of the boot, thinking if the plug hole is full of dielectric that water can't get in? I think it may have helped, I KNOW it didn't hurt anything

 

nice write up
#1 yes
#2 mine seems to work very well for water sealing
#3 what kinda cheap dielectric are you using? mine looks kinda like Vaseline and stays that way for years

 

what kind do You use, sounds good