Ok, just started the coil replacement process, got the passenger side coil cover off. Noticed something off. Two coils (front and back) had green stickers on them, and two had black stickers on them, and NONE had the same part number on them.

Looking from the front of the car towards the back, is the cylinder orientation as follows??

P Side -- D Side
-- BACK --
-- 8 -- 7 --
-- 6 -- 5 --
-- 4 -- 3 --
-- 2 -- 1 --
-- Front --

Reason I ask is because the #8 coils was supposedly replaced just a couple weeks ago. What I found doesn't indicate that, and someone put a BIG glob of RTV on the rear bottom left corner of the coil cover for the passenger side.

The recent coil replacements were supposed to have been #3,5, and 8 via the dealership. More to follow shortly.

rear of car
4 8
3 7
2 6
1 5
Front of car

I found internet access out at disney weeeeeeeeeeee.

thanks joey i am a true LvC junkie now!

the difference in part numbers could likely be because there was a revision.

Ok, the part number for the coils I got from Max is DG-515, and has the following on them:

2W4Z-12A366-BD

The coils in the car that have been replaced have the following on them:

2W4E-12A366-BC

From what I know to be correct there is only one coil that is supposed to be for the 3.9L V8 now and it's the ones I ordered from Max. I'm starting to think that the dealership sold me the older outdated version leftovers at the new revised version price!!!!! Remember that the #5 and 7 were only replaced two weeks ago, and the #3 was replaced in January.

Make sense??

Well, got the old coils out, and sure enough a couple had MAJOR oil build up in the area where the plug is. #1 was soaked down there. I could barely get the plug out due to the suction being created by the pooled oil. Which sucks, because the oil that didn't stay drained to the cylinder, but we'll take care of that later today!! :D

I'm going to go ahead and do the plugs while I'm in there. Any idea what the proper gap is for the V8??

I'm going to go ahead and do the plugs while I'm in there. Any idea what the proper gap is for the V8??

1.0 to 1.1mm is the gap.

That RTV goop should only be between the engine front cover and the front of the head on both sides, but few mechanics probably do it just right. I still had oil in two of my cylinder wells, but I cleaned them up when changing the plugs and it hasn't come back, so maybe they replaced the seals but never bothered to clean out the wells. Maybe you will find the same.

On all the newer coils I have seen, the labels are black. My originals are green and start with XZ. The one I got from O'Reiley's last week was 2W4E-12A366-BD in a Borg Warner box. I got that for about $40.00

Oh...get the car out of the garage as soon as you start it up. You are going to have one heck of a cloud going on for a while (it sounds like).

Ok, the part number for the coils I got from Max is DG-515, and has the following on them:

2W4Z-12A366-BD

The coils in the car that have been replaced have the following on them:

2W4E-12A366-BC

Oh..also, one of the coils in my car that had been replaced already was 2W4E-12A366-BC like yours.

See, that's the startling thing. I just had three coils replaced within the last three months, and all the replaced coils had the "BC" ending, not the "BD." Not cool. I'm looking into this.

I'm hoping all this oil I'm finding is residual considering I JUST had the valve cover gaskets replaced, so I guess we'll know soon enough.

See, that's the startling thing. I just had three coils replaced within the last three months, and all the replaced coils had the "BC" ending, not the "BD." Not cool. I'm looking into this.

I'm hoping all this oil I'm finding is residual considering I JUST had the valve cover gaskets replaced, so I guess we'll know soon enough.

I am pretty sure that the coil I put in my wife's car was a BB or BC, and that was just a couple of months ago. I wouldn't worry about it, honestly. If Ford didn't get it right the second time, they probably didn't get it right the 4th time. They probably changed manufacturers due to price breaks or something. We'll probably see another coil go, but probably not the ones we are replacing.

I hope that oil of yours is just residual too! Mine was only at the bottom 1/8" or so on one side, and the other side was probably not measurable. When I did the valve cover gasket the first time on my wife's car (didn't think I had to replace the center seals...duh) I had oil half way up in a matter of a week! That's when I knew I had to get in there and replace everything. If you get any oil in there in a week or two, you know you have problems. I really couldn't believe that nobody bothered cleaning the wells up while doing that job on my car. I only believed it could be possible when I noticed the original plugs were still in there. They were tight too. 87,000 miles.

Yeah, my car has 76K miles and I'm pretty sure the plugs were the originals too. They were ALL extremely tight and painful to remove. But, I got-r-done. :D

IF the dealership didn't replace the little O-rings when they did the valve cover gaskets, I'm going to blow a gasket. The perimeter valve cover gasket couldn't possibly leak into the plug area, so what are you left with but the O-ring??!! We shall see.

I went with the Bosch Platinum's for the plugs, gapped to the factory .044 spec. Also did a Mobil 1 10W-30 change. She belched a big puff of white smoke upon startup, but settled down nice and smooth.

I'd just like to extend a thanks to everyone who chimed in here, but especially to eL eS, who has been instrumental in keeping me out of the loony bin with this car. Thanks everyone!!! This is definitely a top notch place.

Thoughts and ideas:

First, plugs and coils on this thing is a snap. What a piece of cake to replace the plugs. You guys should see my Trans Am's. Even WITH headers, those things take forever to do. I managed to get everything done with only removing the Air Intake, CCP solenoid and everything else stayed.

Second, WTF was ford thinking designing this thing like they did. If they had only put some sort of clamping retainer that sandwiched the valve cover gasket to the head, we wouldn't be constantly replacing coils due to leakage!!!!

As for the coils, what I noticed was that the coil unit itself seems to be unharmed with the oil leaking. What's happening is that oil is leaking into the plug area, and filling it up. Subsequently, oil starts seeping up into the boot area. Well, the thought struck me, what if you simply remove the boot and properly clean the coiled wire that runs down. Seems to me that all that's happening is oil is getting in there and causing it to misfire by coating the wire and clogging things up. Seems simple enough, so I'm probably missing something very important. Shoot, even if you could find a way to replace the wire thing would probably be ok. Personally, I don't like how soft the connections of the coil to the plug are. I'm used to the 90* boot "snap" connection. :D

Thanks again everyone!!

Yeah, my car has 76K miles and I'm pretty sure the plugs were the originals too. They were ALL extremely tight and painful to remove. But, I got-r-done. :D

IF the dealership didn't replace the little O-rings when they did the valve cover gaskets, I'm going to blow a gasket. The perimeter valve cover gasket couldn't possibly leak into the plug area, so what are you left with but the O-ring??!! We shall see.

I went with the Bosch Platinum's for the plugs, gapped to the factory .044 spec. Also did a Mobil 1 10W-30 change. She belched a big puff of white smoke upon startup, but settled down nice and smooth.

I'd just like to extend a thanks to everyone who chimed in here, but especially to eL eS, who has been instrumental in keeping me out of the loony bin with this car. Thanks everyone!!! This is definitely a top notch place.

Thoughts and ideas:

First, plugs and coils on this thing is a snap. What a piece of cake to replace the plugs. You guys should see my Trans Am's. Even WITH headers, those things take forever to do. I managed to get everything done with only removing the Air Intake, CCP solenoid and everything else stayed.

Second, WTF was ford thinking designing this thing like they did. If they had only put some sort of clamping retainer that sandwiched the valve cover gasket to the head, we wouldn't be constantly replacing coils due to leakage!!!!

As for the coils, what I noticed was that the coil unit itself seems to be unharmed with the oil leaking. What's happening is that oil is leaking into the plug area, and filling it up. Subsequently, oil starts seeping up into the boot area. Well, the thought struck me, what if you simply remove the boot and properly clean the coiled wire that runs down. Seems to me that all that's happening is oil is getting in there and causing it to misfire by coating the wire and clogging things up. Seems simple enough, so I'm probably missing something very important. Shoot, even if you could find a way to replace the wire thing would probably be ok. Personally, I don't like how soft the connections of the coil to the plug are. I'm used to the 90* boot "snap" connection. :D

Thanks again everyone!!


Glad I could help out and no thanks is required. In regards to the coils not being bad; Ford has stated in the TSBs about misfires that a large majority of coils returned to them under warranty were not bad. The problem I have is trying to find a reliable means for testing them so you can know with some degree of confidence that it is good or bad.

The coils I have replaced were dry, but the coils were bad. I wish it was just the spring. Glad you were able to getrdun. One of the reasons I did that doc page for the coils was to show everyone that it is not a complicated job. My Mustang is easier though. :)

SONOFA***CH!!!!!!!!!!!! That infernal problem is STILL there!!!!! I'm really starting to wonder now if it's not the fuel pumps. Dammit!!!! :Bang

On the positive side, the car handled being driven almost 5 hours straight yesterday, then a straight 3 hour trip home today. Low RPM's it's fine, it's just when you get into a high RPM (3000+) and high load (think about 60+% TPS), I.E. more fuel demand area.

I KNOW that if I take it back to the dealership they're going to tell me "Oh, you have a bad coil that's misfiring, and we can't diagnose the fuel pump until those are fixed." I'm tempted to do so just so I can tell them that I just replaced all the coils via myself and the dealership. I'd love to see them stumble through that one.

I'm also wondering if the weak fuel pump (presumed) could be causing a perceived misfire??? Maybe??

I'm also wondering if the weak fuel pump (presumed) could be causing a perceived misfire??? Maybe??

It is possible, or you might have both problems. I can tell you that the coil problems I have experienced in both my LSs, were more noticeable at lower RPMs at medium load. Whenever I kicked the snot out of them, they were fine.

I wonder if the fuel pumps go bad, or if is is the module that drives them. If I run into that problem, I will be tracing down the output to see what the voltage is.

Sorry you are still having a problem. I know how you feel though. My car is on jack stands waiting for replacement inferior ball joints.. Oh, I mean knuckle assys! $$$

My biggest problem is that I'm soooo lost without a service manual. It's like my bible. I really think it's the fuel pumps and not the coils, because owning a GM vehicle with an Opti-Spark you become VERY familiar with what I misfire feels like. This is why I hate dealerships. They get you chasing your tail instead of letting you push forth with your gut feeling.

My biggest problem is that I'm soooo lost without a service manual. It's like my bible. I really think it's the fuel pumps and not the coils, because owning a GM vehicle with an Opti-Spark you become VERY familiar with what I misfire feels like. This is why I hate dealerships. They get you chasing your tail instead of letting you push forth with your gut feeling.


well having gone through bad fuel pumps and misfire fixes myself I would suggest hooking a fuel pressure guage up to the fuel line before the injector rail and watch the pressure duing operation becasue measureing the output voltage is going to prove to be a hard task.

When my fuel pumps were "bad' the car just shutdown and wouldnt restart for about 45 secs to 2 minutes. The dealer diaged it as being the fuel pumps. Within 12 hours of picking up my car it had repeated the problem. Ultimately they replaced the REM, rear electronic module.

Never was the loss of power something that felt like a misfire though it was either on or off. So use the gauge first. Check for oil again as well and inspect the wiring harness' for the CoPs.

2W4Z-12A366-BD


2 = part was revised in '02, this place used to be the decade on pre '00 ford parts
w and 4 used to be year and model
any part number prefix ending with z is a replacement/service part

12000 = ignition part

b = 2nd major revision
d = 3rd minor revision

2W4E-12A366-BC is actually an oem item
e = electrical

2 = part was revised in '02, this place used to be the decade on pre '00 ford parts
w and 4 used to be year and model
any part number prefix ending with z is a replacement/service part

12000 = ignition part

b = 2nd major revision
d = 3rd minor revision

2W4E-12A366-BC is actually an oem item
e = electrical


kool. Thanks for the break down. Do know if there is an online resource with this info?

See, I HAVE put the fuel pressure gauge on the car. Idle it's around 30 PSI. Driving around under light throttle the fuel pressure moves accordingly. Driving around under heavy load I watch the fuel pressure DIVE to less than 10 PSI. The following was the dealers excuses:

"you have a bad coil that's making the car run so bad that we can't get a good fuel pressure reading."

"your bad coil is leaking voltage and sapping it from the fueling system."

Both of which I believe to be 100% bs. The car doesn't feel like it's misfiring AT ALL. It revs smooth, doesn't buck or kick down low, and is seamless accelerating under light to moderate throttle. But if I get into it, it will just pull up to a point and then hang, if not decelerate.

This REALLY has me pissed off because I told the dealership I DO NOT want to spend $1K for replacing a bunch of coils just to find that the fuel pumps are indeed bad, which I've priced out parts only to be in the area of another $1K which I DON'T have. I guess the good news is that I have extra coils on hand now which are good for when the valve covers start leaking again (and I'm positive they will because the dealer replaced them, and never said a thing to me about doing the O-rings).

See, I HAVE put the fuel pressure gauge on the car. Idle it's around 30 PSI. Driving around under light throttle the fuel pressure moves accordingly. Driving around under heavy load I watch the fuel pressure DIVE to less than 10 PSI. The following was the dealers excuses:

"you have a bad coil that's making the car run so bad that we can't get a good fuel pressure reading."

"your bad coil is leaking voltage and sapping it from the fueling system."

Both of which I believe to be 100% bs. The car doesn't feel like it's misfiring AT ALL. It revs smooth, doesn't buck or kick down low, and is seamless accelerating under light to moderate throttle. But if I get into it, it will just pull up to a point and then hang, if not decelerate.

This REALLY has me pissed off because I told the dealership I DO NOT want to spend $1K for replacing a bunch of coils just to find that the fuel pumps are indeed bad, which I've priced out parts only to be in the area of another $1K which I DON'T have. I guess the good news is that I have extra coils on hand now which are good for when the valve covers start leaking again (and I'm positive they will because the dealer replaced them, and never said a thing to me about doing the O-rings).


what the hell were they thinking with not replacing the o-rings. Jeez the only reason I would even crack the VC is to stop the leaking of oil in to the plug wells. Unless the outters were bleeding profusely I wouldnt even bother.

Have you been able to see the pressure drop during the perceived misfires? I guess the bad thing is that you could go through all the trouble of replacing the Fuel Pumps and later find it was the REM or v/v.

You might be able to talk them into installing thier black box data logger and letting you drive with it for a few days and let them diag the problem based off of what the recover. This way you would be out at the most 100 bux for the diag fee. The decide if you want to do the work or let them.

source: http://www.mustangcentral.net/tech/part.html

though like I said...that mainly applies to pre '00 parts

c series transmissions (c3-c6) also use a slightly different naming system fwiw

what the hell were they thinking with not replacing the o-rings. Jeez the only reason I would even crack the VC is to stop the leaking of oil in to the plug wells. Unless the outters were bleeding profusely I wouldnt even bother.

Have you been able to see the pressure drop during the perceived misfires? I guess the bad thing is that you could go through all the trouble of replacing the Fuel Pumps and later find it was the REM or v/v.

You might be able to talk them into installing thier black box data logger and letting you drive with it for a few days and let them diag the problem based off of what the recover. This way you would be out at the most 100 bux for the diag fee. The decide if you want to do the work or let them.

The problem is that at this point I DO NOT trust the dealerships around here. I can already see myself taking the car in and them telling me "oh, you see, now your o-rings for the valve covers are leaking and causing a misfire." My fault for not being informed, but it's just out of hand. I absolutely do not trust the dealership.

The problem is that at this point I DO NOT trust the dealerships around here. I can already see myself taking the car in and them telling me "oh, you see, now your o-rings for the valve covers are leaking and causing a misfire." My fault for not being informed, but it's just out of hand. I absolutely do not trust the dealership.

yeah that is a tough spot to be in and I have been there twice. How many dealers are in your area any chance you can visit anoter one?

The ONLY ones around here are Holman dealerships, whom I don't trust.

Ok, got some news;

Just talked to the Service manager at the servicing dealership. I got told by him that the O-rings are part of the valve cover gasket kit, and were replaced. I informed him that I found a LOT of oil in the plug wells whilst doing the maintenance over the weekend, and also that after replacing the last of the plugs and coils the initial problem still exists. So, he told me to bring the car in first thing Thursday morning.

Yet to be determined if I'm going to get charged for the diagnosis. I'm going to hold to my guns and say no to that.

More to come.

Yet to be determined if I'm going to get charged for the diagnosis. I'm going to hold to my guns and say no to that.

More to come.

Original problem. There should be no charge. Good luck!

yeah if the oil was in there then 12/12 warranty should cover the work.

yeah if the oil was in there then 12/12 warranty should cover the work.

Do you know if that includes labor too?? I honestly think I have a right to demand another free diagnosis at this point considering I've replaced every coil and the problem which was diagnosed as a bad coil is still there.

Do you know if that includes labor too?? I honestly think I have a right to demand another free diagnosis at this point considering I've replaced every coil and the problem which was diagnosed as a bad coil is still there.


I am certain it does but you might have to fight the hard fight to get the diag FOC, free of charge. I do not have my work orders with me but I will check tomorrow to confirm labor and parts. Ya know if you took it in for misfire and they didn't get it right I would think the diag should be FOC. All they can say is no; just be clear that the reason it is back is becasue their fix did not address your concern or failed to continue to work properly that it recurred.

Well, just dropped it off at the dealership this morning. The shop foreman went for a ride with me and the car performed as advertised, and he says to me (while his foot is planted to the floor and the car is sitting at 4000 RPM and holding speed, not going anywhere fast) "Man, I wish I could have seen it do this last time it was in."

Maybe we'll get somewhere this time.

Well, just dropped it off at the dealership this morning. The shop foreman went for a ride with me and the car performed as advertised, and he says to me (while his foot is planted to the floor and the car is sitting at 4000 RPM and holding speed, not going anywhere fast) "Man, I wish I could have seen it do this last time it was in."

Maybe we'll get somewhere this time.

It would be worth paying someone to obseve the dealer when the car goes in for diag. I bet more time than none they pull some grass from the ground throw it to the wind and decide what the problem is based on which way the grass falls.

Well, I'm probably only going to go home with a written diagnosis and go from there on my own. I don't have the cashola to pay the dealerships labor rater or parts prices right now when I can get parts much cheaper and my labor consists of my own knuckle-blood. Hopefully I get a call today, but then again, hopefully not. I'm expecting the call to come in as "Hey, your fuel pump/booster pump/REM is bad."

Hey you should join the NE chapter http://www.lincolnvscadillac.com/announcement.php?f=96
and see if there are any folks in your area that might be willing to help out with the repair.

Hey you should join the NE chapter http://www.lincolnvscadillac.com/announcement.php?f=96
and see if there are any folks in your area that might be willing to help out with the repair.

I thought I had done that, but it didn't reflect it. Just joined up on it. Thanks! :Beer

ya know i think it must have reset. I thought I had done the same thing already but noticed this moring I was not.

I'm changing coils on project that sounds EXACTLY like your situation. Any resolution? Was it the fuel pump or something else on the electrical side?