Our 2003 Excursion 2WD Eddie Bauer has 154k on it. I believe the plugs are original. It runs well enough but the Check Engine light has just recently come on. It doesn't seem to run any different but I'm guessing a misfire in one of the cylinders occurred.

One problem is the OBDII port doesn't work for some reason, so I can't plug my scanner in to see what the problem is.

That said, I want to change all the spark plugs. I know some 5.4L engines had problems with the threaded portion of the plug breaking off and remaining stuck in the cylinder head...maybe due to carbon-covered exposed threads in the combustion chamber.

Is the 2V the problematic engine or the 3 valve? Are standard copper plugs OK or do I need Platinum?

Last night I pulled the easiest coil off (passenger side front plug) and tried the plug with moderate pressure. It didn't budge. Some folks suggested spaying carb cleaner or penetrating oil into the spark plug bore and leaving it to sit overnight. I can't see how the oil would ever make it to the threads.

What happens if the plug breaks off?

Thanks in advance.

Oh yeah, one last note. After failing to get the plug to budge, I reinstalled the coil pack but forgot to plug it in. I started up the truck and it ran smoothly enough for me to not notice anything was amiss. It was only while it was idling and I looked under the hood that I noticed the coil unplugged. How could it run smoothly on 7 cylinders?

 

Check the Cigar lighter/DLC port fuse F2.12 20A which may be blown, it provides power for the OBD scanner.
I would change all the plugs and boots.
Denso boots – 671-0001 work well - $30/10 on ebay and Rock Auto.
The 3v OEM plugs were 2 piece and can break.
The 2v plugs do not extend into the chamber.
I use Motorcraft SP479 platinum plugs which are under $3/ea on ebay or Rock Auto.
The OEM plugs were AGSF22WM.
Blow out the spark plug wells and let penetrating sit in there overnight, it does help.
Passenger side front plug is Bank1, #1 plug.
Be sure to torque the new plugs to at least 25 ft-lbs.

 

Thanks, I will try again feeing better my plugs are not as likely to break off.

 

R&T Babich,

Thanks. That fuse was the problem. Inserted a new fuse and now the DLC works.

Has a strange code for the closed fuel system / inadequate coolant temp..despite the coolant temp gauge reading normal and having great heat.

 

Bad thermostat?

 

The code is P0125. Like I said, good heat, gauge reads normal, warms up normally.

Not sure.

 

yes i had a similar issue. For got what code but it was one bank insufficient fuel rail temp or something. Coolant temp guage read low all the time. My mechanic had changed the thermostat and i thought maybe he put a cooler one in or thermostat had failed or some other random sensor..Drove it that way for years.. Replaced the thermostat myself and found out that he damaged the rubber gasket so coolant was sneaking by... now it works perfect and no more check engine light

 

I've got some random coolant leaks that just recently started. Small drops of coolant suddenly leaking from the lower radiator hose and at the tee in the lower hose. It also looks like some coolant is weeping around where the lower hose enters the block. Basically, it doesn't leak while driving. It sits for awhile and then leaks just a bit, then stops. I think somehow pressure is building up in the lower hose area.

I plugged in my OBDII reader and watched live coolant temps. After driving up hills, around town, and 55mph...the temp never exceeded 170F. Top radiator hose was hot, lower only lukewarm. But very good heat in the cabin! Outside temp was 32F.

Plugged radiator?

 

I know it doesnt answer your question but thats how i knew something was wrong... on the meter my coolant temp never went above like 170 deg. Thats why i went after the thermostat first...and i know... you waited years? Im a truck driver and just dont have time for anything😬

 

Even though the engine has heat it is not reaching ththe temp the computer wants to see. Change thit t-stat and clear the code.

As far as plugs. If they are original at 157k miles they are over due for replacement. The gap at 157k miles is making the coils work overtime which will make them fail!

 

No doubt they need changing, even though it runs great. Planning on changing the plugs tomorrow.

 

Are you gonna do the Tstat too? Really seems like that might be the issue.

 

I don't think it is bad. Top radiator hose gets hot, bottom does not.

 

The P0125 indicates a lazy or partially stuck open thermostat. It keeps the engine from reaching operating temperature within the allotted time for emissions compliance.

 

Everyone says thermostat, and that is a possibility...but I've also read online info cautioning against jumping to conclusions and just replacing the thermostat. Like I said...the top radiator hose was *hot* and the bottom not. So clearly the t-stat is opening at least a significant amount.

I'm thinking about draining the radiator and then running water in from the top hose and see if it flows out the bottom well, just to be sure there's no restriction. Thermostat is cheap and easy; if no restriction I'll probably just change it.

After driving the Excursion 30 minutes yesterday, I let it sit for about 15 minutes and then went out and release the pressure in the overflow tank. It did not leak overnight like it usually does. But what is building excess pressure in the lower hose? I know its not the headgasket - coolant smells perfectly clean.