When to change ignition coils?

[Runnin'OnEmpty]

You might also try cleaning the MAF sensor.
An erratic TPS will cause similar problems too...

 

[410Fortune]

check the top and bottoms of the ignition coil packs, look for any cracks
If you have cracks in the body it is time to replace
Otherwise they seem to last for damn near just about forever

 

[fast_dave]

@MetricMuscle

What @Runnin'OnEmpty said and I'll add to it:

With regards to a MAF Sensor that hasn't been cleaned in ages, in addition to spraying MAF Cleaner on the two MAF Wires, a 2nd step may be required.

Remove MAF Sensor from air intake.

Spray some in the black cap of the can of MAF Cleaner

Dip a new/clean q-tip in the MAF Cleaner solution,

VERY CAREFULLY wipe of the two thin wires on the MAF with the Q-Tip.

Sometimes there's enough burnt on crud on the MAF wires that the Q-Tip turns a light shade of brown.

 

[RickOTR]

DO NOT!, wipe the wires on the MAF sensor with q-tips or anything else. It will recontaminate the wires. Just spray it with MAF cleaner, let it air dry for 30 minutes then reinstall.

At almost 700K on my X, I'm lucky to get 10 mpg city driving. Highway driving I get 23 mpg, doesn't make since I known but that's just the way it is. Age and mileage have put a toll on the old girl. Once had a problem with a Motorcraft thermostat that fell apart causing it to stick open. Replaced it with a stant and gas mileage increased 4 mpg. Best to get a cheap code reader and monitor the coolant temp and how hot the engine is getting.

Ford engineers state that the engine must be at least 188 degrees before the vehicle is consider in proper operating range. It's not functioning until it reaches 198 to 205 degress. Otherwise, emissions and economy will suffer. Also torque converter lock-up doesn't occur until temp reaches 185 degrees. That's what was causing my problem.

 

[koda2000]

If your engine is running too cold (due to using the wrong or a bad t-stat) your engine may not enter "closed loop mode", This will adversely effect your MPG because the ECU will think the engine is cold and it will add more fuel. Closed loop mode is like turning off the choke on an old carbureted engine. It will make a big difference in your MPG, as will old, dirty or worn-out pre-cat O2 senors. Heated O2 sensors (which is what we have) have a 120,000 mile life expectancy.

 

[CDW6212R]

Closed loop is reached way before the coolant reaches operating temperature. I have a T'stat which is opening much sooner than the 180* rating, it runs in the low 170's during Summer. I was using a Scan Gauge constantly last year, and until it broke last Winter.

In my 98 it went into closed loop before 150 degrees, I didn't watch it enough to note when exactly. So the closed loop issue is not relevant unless something is really messed up to keep temps way too low, such as 110-130* etc.

A/F ratio is programmed though based on expected engine temps, water and oil. SO yes at lower than normal temps, the fuel use will be off some. The programmed fuel will be normal at normal temps, but leaner if the temps are too high, and richer if they are too low. But that is based on programming, you can alter the programming to correct for altered temps, if you want to.

 

[koda2000]

When I bought our AWD '00 Mountaineer 5.0L the temp gauge wouldn't more off COLD during the drive home and it barely got an indicated 13 MPG hwy. If you let it sit and idle for 10 mins the temp needle would move up to maybe 1/8th the way up the gauge. It eventually through a P0125 code. I replaced the t-stat (which was apparently stuck in the open position) and the hwy mileage immediately went up to an indicated 22 MPG. I have no idea what the actual coolant temp was when the P0125 got set, but strangely I was still getting pretty good heat. There is a big difference in the AFR table used by the ECU depending on coolant and air charge temp. I have not been able to determine the exact temp at which closed loop mode is reached.

Definition:
P0125 is the OBD-II generic code for the engine computer, or Engine Control Module (ECM), not detecting enough heat in the cooling system before the fuel management system can take control. The ECM has a predetermined value after you start your vehicle to expect a certain coolant temperature.

 

[fast_dave]

DO NOT!, wipe the wires on the MAF sensor with q-tips or anything else. It will recontaminate the wires. Just spray it with MAF cleaner, let it air dry for 30 minutes then reinstall.

Just respectfully sayin' - I guess we'll agree to disagree. Fresh out of the box, a Q-Tip may not be medical grade sterile, but it's clean enough to go in countless baby ears w/o a problem.

In my experience I've never had a problem using a new, clean 100% cotton Q-Tip soaked in MAF Cleaner Solution taking off burnt on crud that the heated wires retain, and the spray alone can't take off.

I've seen the tip of the Q-Tip go from snow white to a slight tinge of brown as I carefully pass it over the wire surface. YMMV

 

[CDW6212R]

Just respectfully sayin' - I guess we'll agree to disagree. Fresh out of the box, a Q-Tip may not be medical grade sterile, but it's clean enough to go in countless baby ears w/o a problem.

In my experience I've never had a problem using a new, clean 100% cotton Q-Tip soaked in MAF Cleaner Solution taking off burnt on crud that the heated wires retain, and the spray alone can't take off.

I've seen the tip of the Q-Tip go from snow white to a slight tinge of brown as I carefully pass it over the wire surface. YMMV

Touching the MAF wires is tricky but not dangerous, they are fragile enough it's best not to touch them if possible. But if you do suspect any buildup that requires contact to remove, spraying it afterwords will remove any contamination from the contact.

 

[fast_dave]

Just sayin' w/ all due respect - I'm 14 years going on 15 on the same MAF - and I just take it easy. It's so simple - remove MAF, place on workbench under lights, insert Q-Tip into MAF Cleaner solution, very carefully with a very light touch just glide & twirl the Q-Tip over the MAF wire surface. YMMV

 

[donalds]

I had to do the q tip trick once now I spray the sh$@ out of it every time I change the air filter
12k miles
The q tip is super soft when soaked in Maf cleaner
simply don't bend or break the wires if you do the only excuse is the one you will be telling yourself

 

[MetricMuscle]

I greatly appreciate all of the feedback and info. New info:
- 2 CEL codes, P304 and P307, cylinders 4 and 7 misfire. No other CEL codes.
- Replaced both coils and cleaned the MAF with MAF cleaner, just sprayed, no q-tip action.
- Verified fuel pressure is good while driving, never dropped below about 62.5 psi.

Still runs the same. Co-worker mentioned something I recall seeing on this board, move the spark plug wires around and make sure they are not overlapping. The wires for cylinders 4 and 7 have pretty long runs and either 1 or both run through a shiny reflective sleeve on the valve cover. I think I'll route them away from the engine and more in open air than next to metal.

 

[MetricMuscle]

In the process of re-routing the spark plug wires, I found cylinder 7 wire was burned inside the plug end crimp fitting. I cut away the bad and re-crimped. She feels much smoother now at idle, I'll check cylinder 4 soon, both have 90* boots.
I definitely wanna replace these wires or at least the plug ends with ceramic. Looks like I could use straight boots on all the cylinders as long as the boot isn't too long. Anybody try all straight boots? Ceramic?
What is the longest length wire we need?
How difficult is it to adapt non-EDIS coil wire ends? Will the clips work on other boots?
I bet there is a whole thread discussing this somewhere......hmmm, I'll search now.

 

[J_C]

^ Why not get the standard motorcraft wire set?

More Information for MOTORCRAFT WR6034

If your wires are the originals that is what I'd do. If they are a more recent year replacement then I'd just replace the 1 for now and wait till replacing the plugs again to do them all.

 

[MetricMuscle]

^ Why not get the standard motorcraft wire set?

More Information for MOTORCRAFT WR6034

If your wires are the originals that is what I'd do. If they are a more recent year replacement then I'd just replace the 1 for now and wait till replacing the plugs again to do them all.

Those metal shields make me mental. A man has to know his limitations and those @%*#$*!$ shields make me angry just thinkin' 'bout'em.

 

[J_C]

Okay then.
They do make sets without the shields. They're much cheaper, but if you want a premium ceramic set instead, it's your money.

 

[koda2000]

^ Why not get the standard motorcraft wire set?

More Information for MOTORCRAFT WR6034

If your wires are the originals that is what I'd do. If they are a more recent year replacement then I'd just replace the 1 for now and wait till replacing the plugs again to do them all.

Denso exact fit wires are also a good choice for less money than the Motorcraft plug wires. I put a set of Denso's on my daughter's Mountaineer and I liked them so much I recently also put a set on my Explorer. IIRC they were about $30 less than the Motorcraft's on RockAuto and you can also get 5% off using their discount code. Plus, if you need spark plugs Autolite plugs are on rebate on RA thru the end of the year with $2 rebate per plug for double platinum's. I wouldn't mess around with rerouting you're plug wires from the OE routing, or looking for ceramic/straight plug boots. It's not necessary or advisable. The PO of my Explorer ruined a brand new set of Motorcraft wires by routing them the "easy way".

 

[MetricMuscle]

Looks like the Motorcraft wires don't have the wonky type heat shields that I currently have. Are they a 2-piece clam shell type or are they 1-piece? If they have a more solid feel and the shields don't flop around and get bent super easy then I might like'em.