I took the Tbird for a drive yesterday, and it was running like crap after it warmed up; after the drive back home, it was obvious it was either having coil pack problems, or it needed plugs and wires.
Looking the engine over after it cooled off a bit, I found rainwater and tree crap in the rear most plug wells; having water or coolant in the wells is known to degrade the plug-wires after a while, so I checked the logbook, and these plugs and wires were installed in 2009, right after I bought the car.
That was about 90k miles ago, all interstate.
So, knowing that pulling the plugs while the engine is warm is a risky proposition, due to there being three threads in the heads, and not wanting to see them come out on the plugs, I waited until today to deal with it.
I have a fresh set of APP103 plugs, one range colder, which works well in Lazarus, and I'm going to go out and replace all this crap.
Just for shits and giggles, I'm going to document everything, as the older info is becoming harder to find.
To get the plugs out you need a spark plug socket, an extension (I use a 12"), a u-joint for same, a 1/4" blade screwdriver, a ~10" piece of 3/8" vacuum hose, some brake parts cleaner, a blow off tool, a shop-vac, and a mirror on a handle tool.
WD40 will sub for the brake parts cleaner, and a can of compressed air like you'd use on a computer will sub for the compressor/blow off tool. Or just a rag and a long, thin screwdriver.
You may wonder, WTF do you need all that crap for?
The spark plug wells get surrounded by all kinds of crap, so you want to vacuum/blow off the top of the engine before you even pop out the plug boots.
Remove the inlet tube; that takes a flat blade screwdriver.
After popping the wires out, you want to look down into the wells, to see what kind of crap in in the wells.
After 10 years, I expect there to be crap, and I've already seen it on #4.
#4 and #8 are the first places to look when one starts missing, as the manifold likes to leak coolant there.
If there is liquid in the wells, it's likely the wires are dead, even if they're new.
I've killed them in a week with a bad manifold.
(Cleaning the sealing surface, and gluing the manifold down with ultra black RTV fixed the leak, but I'll probably break the manifold if I ever have to remove it.)
So, if there's crap in the wells, hit it with cleaner, then blast the crap out of the wells with the blow off tool, while sucking it up with the shop-vac. You don't want brake parts cleaner or wd on your paint.
Make sure the wells are clean and dry BEFORE removing the plugs, because anything in there will drop into the cylinder.
Stuffing a valve with an acorn remnant is a possibility; I saw it done once on a mustang.
If you don't have fancy tools like a compressor, or a can of compressed air, or a shop-vac, you can clean them out with a rag and a thin screwdriver; it's a pain in the ass, but you can do it.
Keep going until they're clean.
Make sure the engine has sat overnight before you loosen the plugs.
I've had these out, and I always use anti-seize on everything I remove. Taking the Plugs Out:
But I still won't mess with the plugs hot.
If you take them out hot, you will probably see aluminum embedded in the threads. A Helicoil is in your future, at that point, and most shops won't install them without pulling heads.
At least we don't have 3V heads, lol.
Using the 5/8" spark plug socket, with the u-joint just above it, and an extension, remove the plugs. Be gentle.
I usually tighten very slightly, then reverse and remove. Barely move it the first time.
You will see the swivel helps clear the fuel rail. Don't pull the fuel rail, as some people say.
The rear plugs are a bitch, you might need another swivel. I did on one car.
If the plug drops out of the socket, a magnet on a stick or screwdriver will pull it out.
Putting the Plugs back in:
Stick the plug in the piece of vacuum hose, Apply anti-seize to the threads, and drop it down and thread it into the hole.
This make the process so much easier; the hose makes it easy to not cross thread, as you can't apply that much torque.
The tightening angle for both new and reused spark plugs is 1/16th of a turn, after the plug 'seats'.
I went thru last night and checked the gap on the plugs.
Factory gap is 0.054".
Blowers, high compression, Nitrous, all make a difference; some people go as far as 0.032.
The tighter the gap, the lower the energy of the spark, except in extreme cases, as listed above.
People will tell you plugs are pregapped. This is shit.
No one at the part store is selecting you plugs for your car; they're pulling from a bin of XXXX plugs.
If they get dropped, the gap can be zero, so check it.
I use a 0.060 Wire type gauge as a 'no go' gauge, and an 0.050 as a 'go' gauge; exactness is not that required.
A wire type gauge will not be dependent on you holding it a the correct angle to read correctly.
The ones you remove are going to be 0.070 (or larger), and it's rarely the plugs that fail. Usually it's the wires, because the high voltage will increase to match the gap, and at some voltage the wires will leak, carbonize, and fail.
Our coilpacks can generate over 160kV in the right setup, so don't run your hand up the wires while it's running to find the bad spot.
You won't do that twice, anyway.
I have a coilpack sealed in a block of insulation I use for projects, it can throw an arc about 3" in dry air.
They can kill you, no shit.
There are dozens of threads on what plugs are the best. OEM is best for me, but Autolite is usually cheaper than Motorcraft. And they made the OEM.
I don't like changing plugs every 15k miles, so Coppers are out for me.
But, if you're willing to regap and dress them every 10-15k miles, they are the best for high performance.
Our cars use a "Waste Spark System". What this means to us is that one side of the engine wears the tip of the plug, one wears the curved electrode.
This is why you want "Double Platinum" plugs; they have a little puck of platinum on both electrodes, and both sides will wear out at the same time.
All of the "Special" plugs will wear the tiny tip off down into the center electrode in about 15k miles.
I did this personally with a set of Bosch twin electrode plugs. 4 of them had cracked the center into pieces when I took them out.
The keyword for me is "Double Platinum".
Odd note: Ford being cheap, there were originally two part numbers for our plugs; one had the platinum puck at the tip, one on the curved electrode.
Technically, you could wear out a set of double platinums, regap them, and swap sides, and get another 100k out of them.
Only the side where the electrons land get blasted.
I stole this list from a post by Superduty, here:
AWSF-32C / stock heat range - copper plug
AWSF-22C / 1 Heat range colder - copper plug
AWSFA-12C / 2 Heat range cooler - copper plug
AGSF-32C/ Recommended for FRPP heads(not sure on heat range)
TR-55/ 3951/ Stock Heat Range
TR-6/ 4177/ 1 Step Colder
BP7EFS (PN - 3526) BR7EF (PN - 3346) two steps
R5724-8 (PN - 7317) two and a half steps
R5724-9 (PN - 7891) three steps
R5724-10 (PN - 7993) four steps
764s / Stock
103s / 1 heat range cooler < this is what I'm putting in. Autolite makes the Motorcraft brand.
AR94 / 2 heat range cooler
AR93 / 3 heat range cooler
AR92 / 4 heat range cooler
YS-59C / -3 or -4 below stock heat range
IT16 / stock heat
IT20 / -1 heat range
IT22 / -2 heat range
IT24 / -3 heat range
Motorcraft sparkplugs have changed part #'s and some are now only aval in a full thread design, new part #'s are as follows......
SP-447 replaces the AWSF-32-C & AGSF-32-C, Full Thread design-stock heat range in a copper core
SP-505 replaces the AWSF-22-C & AGSF-22-C, Full Thread design-1 step down from stock, also copper core
SP-494 replaces the AWSFA-12-C still a 1/2 thread design-2 steps down from stock, copper core
There are a ton of wires out there. IDK about those, I always buy the Stock Motorcraft wires; they're expensive, but last a lot longer than the one set of pretty aftermarket ones I bought.
They did look cool, but the 10mm wires don't fit the holders, and they died after a year.
This is the fun part.
But, I've done this enough to have it down. (famous last words, lol)
Here's the factory diagram:
You will notice as you pull them out of the box that there are varying lengths.
You can either remove one at a time, and match it up, or here's a list of the lengths that go to each cylinder:
CYL# ..............Number ranking of length, 1=shortest, 8= longest.
Cylinder #1 is front passenger, #5 is front driver's side.
Left coilpack is:
Right Coilpack is:
Use the Dielectric Grease LIBERALLY all over the boots, inside the boots, inside the coilpack ends.
I apply a 1/4 bead around the boot to try to seal the spark plug well; I've had mixed success with that.
Now I have shade over the car, so I'm going to go do it.
I hope this helps someone; I was looking at my notes, and they were everywhere, so I thought I'd put it all here.