Tara, obviously I cannot guarantee that the COPs (Coil On Plugs) are the cause of the misfire, but it sure is highly likely. What was the odometer reading when you got it?
I believe the link I posted earlier talks about testing the resistance of the coils. If you can do that it would help.
Since you have COPs you don't have ignition wires. So you can cross that of the list.

As far as the cost is concerned: if a potential buyer was to test drive it now what do you think he or she would say? No matter what your asking price, he would likely try to haggle a substantial discount or walk away. Of course $500 for COPS is nothing to sneeze about either.

 

Many times once an ign syst problem is repaired the whistling may disappear unless it is just a dry belt. I'm pretty sure you can't hit me from there,but I would definitely change all the coils. They don't always throw a code just drive you nuts especially if you replace one then a short while later another etc. They do break down under load and it can be very annoying when there is more than one bad one. By the way, a bad coil on a coil on a plug system can take out the PCM and they go for more bucks than all the coils put together.

 

yeah now I remember that's why he said he couldn't do the wires because it had coils and they were more expensive!! I have done so much to it, it's hard to remember every little detail.. I am pretty sure you are right though, when I bought it it was over 200,000 as well. I haven't really got to drive it a lot due to all the issues.. as for the pcm that is what is reading on my car memory fail.. it is overheating I have to keep the heat on high to keep it in the normal range, if not it overheats, I have tried everything for it too, I am about to try a thermostat, but a local shop told me it would over heat wheter the heat was on or not if it was the thermostat, there isn't any visible leaks fans are both coming on each time I have checked.. I am now guessing a blocked radiator since the antifreeze is full or the stat, but at this point I really just don't know anymore I have pretty much had it with vehicles!! I should have been a mechanic, everyone needs one of those at some point!! the only code the expedition was throwing was battery pack, but the fuse was blown so he reset the codes told me drive it a little bring it back and hell check it again.. I will go do that tomorrow.. as far as changing out the coil plugs/packs how hard is it? can I do it myself? thanks again guys for all your help I really appreciate it, these 2 cars are our only transportation for me and my 2 toddlers so we really depend on it especially since we are expecting again!!

 

Tara: first of all congratulations to your growing family!
Secondly: you definitely earned my respect for taking on shade tree mechanics.

Now to the COPs: in principle they are easy to replace. There is a wire harness and hold down bolt. Remove both, pull the old COP off the plug, put on the new one and bolt it down, reconnect the wiring harness. In some vehicles though they can be difficult to get to. I do not know if this is difficult in your vehicle. And while you have the COP off use a Q- tip or something to check if there is oil or moisture down by the plug. Do this at each plug.

Now that overheating adds a new dimension. Sometimes overheating is caused by a busted head gasket. Do you loose coolant? Is the exhaust steamy white?

 

Also, Are we really sure it is actually overheating ?
There are times when there exists a poor connection where the gauges are involved and turning on an additional load allows the gauge to get a better connection and provide a more accurate reading.

 

Thanks for all your reponses.. as for yhe expedition I will try the coil plug and check for oil and start the process of elimination to figure out which coil if any, but hopefully that is what it is.. about the overheating in the 01 chrysler 300m I do know it is in fact overheating, you can hear the reservoir boiling and now ots starting to overheating faster and I have to keep heat all the way up now to keep it at the half way mark. For this car a notch below halfway is normal. The oil isn't milky, but I do sometikes notice white smoke, but it's cold here and im not sure if thats why or not. Maybe it wasn't cold enough to smoke, but "coming from my step dad" its not the head gasket.. the pcm memory fail is the only code and im not sure if that could cause it, so I am thinking a block in radiator or thermostat, but at this point I don't know it could be anything there could be a small crack invisible to the eye and not big enough to cause a leak, but enough to throw of pressure.. I am open to any ideas.. thanks again

 

well, I was going to change all the coil packs, but unfortunately I couldn't get them all because the store only had 2 in stock.. it is driving a little better not misfiring half as bad it's actually tolerable now, but I can tell it needs them all changed, which I will do when they get them in stock.. I also changed the belt and there is still a squalling noise, I also have an exhaust leak so the manifold gasket needs replaced, I have been smelling gas.. we can't figure out where the squalling noise is coming from, but a guess said the timing belt and I was told by the same person they had one in their garage right now working on it and nothing has stopped the noise, so now they have to replace a motor.. I was told to get rid of it asap to take it and trade it in because in time it will go.. the noise is when I push the gas, I tried belt conditioning and it made it worse.. it use to come and go now its always doing it.. ugh I was also told I might as well start with changing the thermostat on the 01 Chrysler 300m since the part is cheap ne way.. so that will be my next assignment lol.. thanks again for all your help..

 

When it rains it pours.
I have some reservations about that engine having a timing belt.
Speaking for myself, belt dressing is putting on a band aid that has an infection already on it. Never use the stuff nor recommend it! When the belt was off did anybody spin the pulleys to see if any one of them was rough/noisy? The only one you cannot move is the pulley on the crankshaft. You can spin and check the alternator, the power steering pump, the water pump, the idler pulley, the tensioner and the air conditioning pulley.
Either someone is giving you some faulty info or they just don't know , but it seems like you are getting the run around.
There is something to be said for trading in the vehicle, but the problems you are seeing could be from lack of proper maintenance or somebody doesn't know what they are doing.
The folks on this forum try to provide accurate info from their own experience.

 

Hank,
I thibk you misunderstood me. The problem has been fixed the expedition now runs great!! The noise stopping was a bonus. I had bo idea a broken coil pack harness clip could cause all those problems, the misfire yeah i understand that, but the whistling noise..no i never thought that was the reason for it.. as soon as we put a nrw harness on all the problems went away (for now at least) no more misfires no kore squealing!! Thanks again for all your help.. now on to fixing my car.. thanks again!!

 

Coming up on 300,000 on a 5.4 and has all the same misfire problems talked about for years.

It's not the transmission.

I figure since the Ford guys R&R'ed the plugs [two days $400] 150,000 or so miles ago with BOSCH 4 prong deals [what's wrong with Ford replacements?] it time.

Here is the mystery. When it's way below zero, she runs perfect. Even when the check engine light is on or blinking ... I'm guessing a bit rich works well at low temperature.

And then when warm the normal missing at any speed other then coasting happens. This has been going on for years and it really doesn't bother me anymore. Always starts, always runs, always pulls the load. It will never leave me stranded. Starts faster then I can let go of the key.

So I figure
[1] the spark is blasting through the spark plug boots and going to ground.
[2] the coils are firing.
[3] the injectors are injecting [they could be worn to a point of not being precise]
[4] the cure, plugs and new boots between the coil to plug [$7.00 per boot at AutoZone or O`Reilly's]
[5] The only problem is digging down to these components. Seems every darn thing above these components is in the way and I'm not going to do it in the winter.

Amazing but it still has the factory
[1] timing belt
[2] water pump, cooling is the optional 'get home mode'
[3] water hoses, heater hoses, heater fans, controls
[4] transmission, R&R'ed the fluids 4 or five times
[5] steering and pump, R&R'ed the fluids yearly
[6] master brake and calipers, R&R'ed the fluid yearly
[7] A/C makes really cold air.
[8] heaters make really hot air, controls work fine.
[9] every once in a while I change the oil when she drops 2 quarts
[10] plug in block heater still works, but don't use it.
[11] body has dissolved due to rust.
[12] everything electric still works 'cept running board lights
[13] all brake calipers R&R'ed three times and maybe 12 sets of pads
[14] had Ford R&R everything that moves in the front end, $2600
[15] rear axle bearings, $300 for the pumpkin, yearly lube change
[16] still driving around with LF CV boot torn for years
[17] original exhaust, but cast iron manifold is starting to look 'thin and pitted' heat shields rusted off
[18] had to R&R the alternator a few years ago
[19] 4 batteries, biggest darn one I can fit in the hole max cc amps
[20] flips in and out of 2wd, awd, 4wd, 4wd low just fine
[21] same U-joints in the drive shaft
[22] nice and dry underneath, no liquid leaks, no vacuum leaks
[23] emergency brake, ever tried to use it,
[24] interestingly the first rust broke through the body pan at the e-brake boot
[25] 3 or 4 fuel filters, same fuel pump

I mean this 1997 Expedition owes me nothing. I still love it.

skip.