REVISED SPARK PLUG USAGE for 4.6L [Archive] - MercuryMarauder.net Forums

schuvwj

12-24-2003, 09:42 PM

16856 2003 4.6L 4V MUSTANG MACH I, MERCURY MARAUDER, REVISED SPARK PLUG USAGE.
SOME 2003 MERCURY MARAUDER, MUSTANG MACH I, LINCOLN AVIATORS WERE BUILT WITH 4.6L 4V ENGINES USING SPARK PLUG PART NO. (AWSF-32E-M (F6LE-12405-AC) AND
SPARK PLUG PART NO. AGSF-32W-M (XS2E-12405-AB).
WHENEVER THE SPARK PLUGS REQUIRE REPLACEMENT FOR SERVICE, USE PART NO. AGSF-32W-MF6 (XS2E-12405-AB) ALSO, THE REPLACEMENT SPARK PLUGS ARE OF THE FULL THREAD DESIGN AND ARE RECOMMENDED FOR ALL APPLICATIONS. OWNER GUIDE AND SERVICE PUBLICATIONS ARE BEING UPDATED TO REFLECT THIS CHANGE.

My MM came with AWSF-32E-M from the fatory and the full threaded replacement plug is AGSF-32W-MF6.
This would explain why my #7 spark plug gets motor oil around it in the plug hole and fouls the plug. At the factory the counter bore for the plug seat was machined too deep and the plug bottms on the threads before it properly mates with the Cly. head seat.
I see the IT20's have threads all the way up the plug seat so those plugs are all right!
Dennis can you tell us what the cooler plug number with full threads we should use for Motocraft AWSF-A12C?

Thanks!

RF Overlord

12-25-2003, 07:52 AM

Originally posted by schuvwj
I see the IT20's have threads all the way up the plug seat so those plugs shold be all right!

Bill:

Thanks for that info...I'm glad I don't have to run out and check mine...

(dodged another bullet... :D )

TripleTransAm

12-25-2003, 10:39 AM

Originally posted by schuvwj
This would explain why my #7 spark plug gets motor oil around it in the plug hole and fouls the plug.

Not trying to argue but what would the plug seat have to do with oil fouling? I'll have a close look at the manual but I don't believe the plug comes in contact with any oiled surfaces...

Number 7, eh? Oil fouling, eh? Sounds VERY familiar to me... very familiar... shudder

schuvwj

12-26-2003, 10:26 AM

Originally posted by TripleTransAm
Not trying to argue but what would the plug seat have to do with oil fouling? I'll have a close look at the manual but I don't believe the plug comes in contact with any oiled surfaces...

Number 7, eh? Oil fouling, eh? Sounds VERY familiar to me... very familiar... shudder

Yes Steve this does sound very familiar.

Due to the counter bore issue above I pulled all of my Motorcraft AWSF-A12C plugs today and reinstalled my Denso IT20's since they had threads up to the plug seat area.

I noticed AGAIN the plug in number 7 cylinder had a heavy coating of oil on it from the plug seat down. I also noticed that ALL my plugs both the Motorcraft I removed today and the Denso from before seem to be running cold/black not tan colored. So I very very carefully set the gap on the Denso’s at 0.052”
Maybe I need to drive it harder? Like Mac said the harder you drive these cars the better they run!

Number 7 plug looks like I am leaking oil past the plug threads up into the plug seat area, but I’m not leaking compression past the plug seat? I have always torque my plugs at 12 Ft Lbs.

Steve to answer your question about oil. I think my cylinder number 7 has an oil problem from the valve guide issue we talked about months ago but my F/M dealer says there is no problem here.

I have not had to add any oil between oil changes, stays on full!

Around and around we go where we'll stop nobody knows!

Have a Good Day!

hitchhiker

02-20-2005, 09:00 PM

Yes Steve this does sound very familiar.

Due to the counter bore issue above I pulled all of my Motorcraft AWSF-A12C plugs today and reinstalled my Denso IT20's since they had threads up to the plug seat area.

I noticed AGAIN the plug in number 7 cylinder had a heavy coating of oil on it from the plug seat down. I also noticed that ALL my plugs both the Motorcraft I removed today and the Denso from before seem to be running cold/black not tan colored. So I very very carefully set the gap on the Denso’s at 0.052”
Maybe I need to drive it harder? Like Mac said the harder you drive these cars the better they run!

Number 7 plug looks like I am leaking oil past the plug threads up into the plug seat area, but I’m not leaking compression past the plug seat? I have always torque my plugs at 12 Ft Lbs.

Steve to answer your question about oil. I think my cylinder number 7 has an oil problem from the valve guide issue we talked about months ago but my F/M dealer says there is no problem here.

I have not had to add any oil between oil changes, stays on full!

Around and around we go where we'll stop nobody knows!

Have a Good Day!

Assuming that I will install the revised plugs, Which ones would be one step cooler to go with the chip install?

Thanks

David

David Morton

02-20-2005, 09:16 PM

Oil fouling on a single cylinder can only come from the intake valve guide oil seal letting too much oil pass into the intake charge or a broken oil control ring (in really bad cases). In either of these cases, if the plug is fouling and causing a miss in the cylinder, it is an issue. If it isn't causing a miss, and just looks a little oily, it isn't really "fouling" and it may not be necessary to go inside the engine. If the valve guide has gone south, it will eventually fail to the point the valve will go bad or the plug will foul and cause a miss. If you've made a complaint of a miss or smokes at idle while it's under warranty, you'll have plenty of ammo to get it fixed under warranty when it does go bad.

However, if the oil seal is just a little loose and it's not fouling the plug, you can expect that particular guide to last a lot longer than the others because it is getting more oil.

BillyGman

02-20-2005, 10:05 PM

David Morton has it correct, because the fact of the matter is, that even if the threads on the plug you're using are wrong, that wouldn't have anything to do with oil being on them. And if the plugs are black when you remove them, it depends on whether they have a black coating on them that's wet (which would be oil), or a black coating that's dry and sooty looking ( which would be an indication of an improper engine tune which has an air/fuel ratio that's too rich).

FordNut

02-21-2005, 05:21 AM

I'll bet Bill has his fouling issues resolved by now, since this thread was started in 2003.

But the spark plug thread issue is well known, to the point that some Lightnings have been known to blow spark plugs out of the head. But I'm not sure of a revised part number for the full-thread AWSF-12 (colder) plugs.

metroplex

02-21-2005, 05:46 AM

http://www.redpulsar.us/~coldfusion/film14/sparkcomparo.jpg

I'm running the AGSF-12FM1 on my 4.6L SOHC V8. It is very similar to the Denso Iridiums, but at $4/piece.

BillyGman

02-21-2005, 06:23 AM

http://www.redpulsar.us/~coldfusion/film14/sparkcomparo.jpg

I'm running the AGSF-12FM1 on my 4.6L SOHC V8. It is very similar to the Denso Iridiums, but at $4/piece.okay, this^ is interesting because there's 6 threads on the plug to the left, and 10 threads on the plug to the right. However, the real big question here that isn't answered is exactly how many threads are there on the Marauder engine cylinder heads? because if there are 6 or less threads on the heads, then having more than 6 threads on the plugs won't do you any good at all. I've heard about some late model ford 32 valve cylinder heads having only four threads in the plug holes. the Mustang guys have talked about that issue in the past. I don't know if that's true or not, but if it is about our cars, then the sparkplug in the right picture will not be any different than using the one in the picture on the left. Can anyone answer the question about the cylinder heads? that's the important one here.

KilledKenny

02-21-2005, 10:29 AM

okay, this^ is interesting because there's 6 threads on the plug to the left, and 10 threads on the plug to the right. However, the real big question here that isn't answered is exactly how many threads are there on the Marauder engine cylinder heads? because if there are 6 or less threads on the heads, then having more than 6 threads on the plugs won't do you any good at all. I've heard about some late model ford 32 valve cylinder heads having only four threads in the plug holes. the Mustang guys have talked about that issue in the past. I don't know if that's true or not, but if it is about our cars, then the sparkplug in the right picture will not be any different than using the one in the picture on the left. Can anyone answer the question about the cylinder heads? that's the important one here.

Basically it the offset of the cylinder head threads thats in question. The AWSFA-12C does not have enough threads to seal on the tapered part of the spark plug with a cylinder head thread that is set to high into the sparkplug hole. (excuse my paint shop abilities :) ) Also if he is getting oil on the threads make sure oil in not leaking into the sparkplug hole via the valve cover gasket o-ring. If oil is leaking into the hole it will show up when removing the sparkplug.

BillyGman

02-21-2005, 02:03 PM

Basically it the offset of the cylinder head threads thats in question. The AWSFA-12C does not have enough threads to seal on the tapered part of the spark plug with a cylinder head thread that is set to high into the sparkplug hole. (excuse my paint shop abilities :) ) Also if he is getting oil on the threads make sure oil in not leaking into the sparkplug hole via the valve cover gasket o-ring. If oil is leaking into the hole it will show up when removing the sparkplug.Thanks for your explanation on this. And for your detail about the valve cover gaskets being a possible source for oil. I believe if that was the case, then he would have oil on the part of the plugs that do NOT enter the combustion chamber. Correct me if I'm wrong though.

As far as the differences of these plug threads goes, as many blunders as Ford and other car manufactures have made in the past, I still find it a bit difficult to believe that they've overlooked something like the need for adequate threads on the sparkplugs that they specify for these engines, since this is very basic stuff. I can't help but to think that there's some specific reason, and need for these plugs that have less threads that we're all unaware of. And IF that's the case, perhaps there can be something detrimental to our engines by us deviating from the specified design. Just a thought.:dunno:

KilledKenny

02-21-2005, 03:38 PM

Thanks for your explanation on this. And for your detail about the valve cover gaskets being a possible source for oil. I believe if that was the case, then he would have oil on the part of the plugs that do NOT enter the combustion chamber. Correct me if I'm wrong though.

You are somewhat correct but what you haft to consider is 2 things, severity of oil leak and removal of spark plug. If it has a small oil leak there may only be a small amount of oil at the very bottom of the spark plug. If you looking at the plug it would probably just reach the first machine surface above the taper. Now if you remove the plug the oil has to go somewhere. During removal it runs down the threads and into the combustion chamber. When the plug comes out it will have oil on all the threads.

As far as the differences of these plug threads goes, as many blunders as Ford and other car manufactures have made in the past, I still find it a bit difficult to believe that they've overlooked something like the need for adequate threads on the spark plugs that they specify for these engines, since this is very basic stuff. I can't help but to think that there's some specific reason, and need for these plugs that have less threads that we're all unaware of. And IF that's the case, perhaps there can be something detrimental to our engines by us deviating from the specified design. Just a thought.

Just so you that example pic I gave... I have not seen an cylinder head machine that way yet. The main reason ford changed spark plug thread was due to a Ford saving money and making a more universal spark plug that could be used in any vehicle and or manufacturer. Ford has a part crossover book that give a list of what plugs and filter can be used in different manufactures (Chevy) and the old spark plugs have all been discontinued and updated to the newer numbers. Hope that helps. :)

BillyGman

02-21-2005, 04:17 PM

and the old spark plugs have all been discontinued and updated to the newer numbers. Hope that helps. :)Just because they have new numbers doesn't mean that they are any diferent in the thread design. i say that, because I just changed the sparkplugs on my Marauder this past weekend, and last saturday i bought the plugs from the Ford dealer parts department, and they have new numbers but are the same design as the old ones. So what you're saying is only part of the story on this. furthermore, if you look at where the threads begin on that plug(or perhaps i should say where they end) you'll see that it's actually a shoulder where the plug sits on, and the straight part that's smooth without threads, will not be able to go into the heads since it will not get by the threads of the cylinder head. So in essence, these original type of plugs do NOT sit on the tapered seats at all, but on the squared shoulder.

schuvwj

02-21-2005, 06:31 PM

Assuming that I will install the revised plugs, Which ones would be one step cooler to go with the chip install?

Thanks

David

David I have since installed NGK TR6 spark plugs which are colder than stock and have threads the whole length of the plug. I have used the NGK TR6's now for over 20,000 miles and I am very please with them! No oil on threads anymore.

Have a great day!

BillyGman

02-21-2005, 06:50 PM

If you get a chance, and you have a scanner, please post a pic of the new plugs...that is if you even thought of taking one of them before you installed it. Just a shot in the dark on my part I guess. You have my curiosity about this.

KilledKenny

02-22-2005, 08:45 AM

Just because they have new numbers doesn't mean that they are any diferent in the thread design.

You are absolutely correct. There is always more reasons why a company changes product design. Design flaws, manufacturing costs, multiple variants of the same product. One main reason from my understanding was rust. The new plugs are now all nickel plated. The old plugs were noted for rusting out in the salt belt states with engines that had plugs externally mount head design. This costs Ford in warranty department claims.

furthermore, if you look at where the threads begin on that plug(or perhaps i should say where they end) you'll see that it's actually a shoulder where the plug sits on, and the straight part that's smooth without threads, will not be able to go into the heads since it will not get by the threads of the cylinder head. So in essence, these original type of plugs do NOT sit on the tapered seats at all, but on the squared shoulder.

Majority of ford cylinder heads have only 4-6 thread in the head starting from the combustion chamber out. After the thread part there is the machined part (non threaded part) which is actually larger diameter then the threaded part. They will always seal on the tapered part of the plug. If you would like I will try and take a pic a cylinder head to give you an idea of what I'm taking about. :)

BillyGman

02-22-2005, 12:41 PM

If you would like I will try and take a pic a cylinder head to give you an idea of what I'm taking about. :) That would be very revealing if you did post apic of a 4.6L cylinder head. I'm wondering if the DOHC heads atre different in this respect than the SOHC heads. if so, then ofcourse I'd be interested in seeing a pic of the DOHC head.

KilledKenny

02-23-2005, 07:55 AM

Ok, I'm currently taking some pic of some spark plug holes 4.6 SOHC, 4.6 SOHC Truck, 4.6 DOHC (My Marauder) 5.4 SOHC Truck and a 2.5 DOHC. The pics will not be that great due to the bore-scope design and my camera.
I will also post some pics of original, replacement plugs as well as the Ford Iridium spark plug (AGSF-22Y-PC) that I am using in my vehicle.

BillyGman

02-23-2005, 09:48 AM

metroplex

02-24-2005, 07:04 AM

Bill G-Man:

My 4.6L SOHC V8 originally uses the plugs on the left (AWSFA-12C) for use with the custom tune.

I then switched to the AGSF-12FM1s (on the right) which, IIRC, are stock plugs from late model Lightnings. Even though there are more threads, it fits just the same on the heads with only a few threads.

THe 2004 Cobra uses:
AGSF-22FM1 (1 heat range hotter than the AGSF-12FM1s that I am using).

Based on the way Motorcraft plugs are numbered... the 4.6L DOHC V8 on the 03-04 Cobra would take the plugs on the RIGHT of my pic w/o any problems.

I am not saying the AGSF-12FM1/22FM1 plugs will eliminate the ejection problem, but I'm just saying they will fit the 4.6L SOHC V8 heads regardless of how they look. From the sound of it (04 Cobras using AGSF-22FM1), the Marauders should be able to use the same ones. These plugs are of an iridium design if I'm not mistaken. Platinum plugs are usually just copper-style plugs with a platinum slug on the electrode. The 12FM1/22FM1 Motorcraft plugs have TINY electrodes - copper or platinum would easily wear out... leaving the choice material as being of an iridium variant. At $4/ea they are a much better deal than Denso.

BillyGman

02-24-2005, 07:59 AM

Bill G-Man:

I am not saying the AGSF-12FM1/22FM1 plugs will eliminate the ejection problem, but I'm just saying they will fit the 4.6L SOHC V8 heads regardless of how they look.
Yes, that's exactly my point though. Some of the other posts in this thread seemed to suggest that going with these other plugs would somehow eliminate or prevent the alleged possibility of the plugs getting pushed out of the threaded holes of the cylinder heads on our Marauder engines. However, if the cylinder heads on our engines are only going to occupy and use 6 threads or less of on any sparkplug that's used, then simply by using a plug that offeres more threads than the cylinder heads can use will NOT eliminate the plug from dislodging from the heads as it was implied.

You can install a sparkplug that has 25 or 30 threads on it into the cylinder heads on your engine, but that doesn't mean that it will be held in the head anymore securely than the original plug with 6 threads will be IF the cylinder heads don't have anymore than 6 threads machined into them. However, all of this is conjecture until one of us can get a good enough look at our cylinder heads while they've been taken off of the engine block to actually see for ourselves exactly how many threads there are in these cylinder heads of ours.

metroplex

02-24-2005, 08:36 AM

I went with the AGSF-12FM1 plugs because they were the right heat range, and they're supposed to be an improvement over coppers.

My AWSFA-12Cs were worn out at the electrode. I expect only 20k-25k miles out of them, and would prefer longer-lasting performance iridium plugs.

I always use anti-sieze on the threads, and torque it to the FSM spec (15 ft-lbs).

cyled

02-24-2005, 09:10 AM

Just thinking out loud...

"IF" the issue is the plug not seating correctly in the cylinder head, couldn't that be a source of blow by or at least a "leak" therefore not allowing for proper combustion? If that is the case, couldn't that cause the darkness on the plug?

I believe the spark plug holes are tapped all at once when they are machined. If the number 7 tap was off, having a little bit more thread on the spark plug could make up the difference. It may only be the only one extra thread that is needed to properly seat.

Anyway just my .02 worth. :confused:

BillyGman

02-24-2005, 09:25 AM

I believe the spark plug holes are tapped all at once when they are machined. If the number 7 tap was off, having a little bit more thread on the spark plug could make up the difference. It may only be the only one extra thread that is needed to properly seat.

Anyway just my .02 worth. :confused:You're talking my language, because I happen to work in a room that's located inside of a machine shop. A rather huge machine shop at that. I think you're missing the point. How many threads in a hole being tapped with the same thread pitch as several other threaded holes are is NOT determined by how accurate the tap is, nor how worn it is, but is determined by how deep the hole is. For example......I know by looking at the sparkplugs that are used in our Marauder engines that the threaded holes in the cylinder heads are 24 threads per inch. So if the hole that's being tapped is only a quarter of an inch deep, then there will be 6 threads tapped into that hole regardless of what condition the tap is in that's being used as long as you're using a tap that's made with 24 threads per inch. So as long as the medal where the hole is that's been drilled is one quarter of an inch thick, there will only be 6 threads in that hole as long as the intended tap of 24 threads per inch is used. It would have nothing to do with the tap being "off" as you've implied. And if the wrong tap was used to begin with (such as one of 20 threads per inch) then the car would've never gone off the assembly line since nobody would've ever been able to thread the intended sparkplug into that hole because the threads would've been different.

metroplex

02-24-2005, 09:28 AM

BillyGman

02-24-2005, 09:32 AM

From all the cases I've heard where the plug(s) ejected out of the motor (taking out a COP coil or two), the threads on the head were GONE (left with the plugs).

Experts have analyzed this and blamed it on the low number of threads holding the plug (like 2-4 threads on the head).

This is more common on trucks (5.4s) for some reason, and detonation at load is one major cause of this problem.

A solution is to use Timeserts. Theyre so good that people often contemplate installing them on all 8 plug holes. You must mean "slimserts". We use them where I work. But the ones that you're talking about must make the hole deeper by offering more threads than the original hole did. However, I've never seen slimserts being used to elongate a hole, but simply to repair a hole, or prevent it from having to be re-machined in the first place in the event of thread damage.

But either way,the fact remains that using a sparkplug that has more threads on it than the cylinder head holes do, will not be of any benefit in the prevention of dislodging the plugs from the holes.

cyled

02-24-2005, 09:36 AM

You're talking my language, because I happen to work in a room that's located inside of a machine shop. A rather huge machine shop at that. I think you're missing the point. How many threads in a hole being tapped with the same thread pitch as several other threaded holes are is NOT determined by how accurate the tap is, nor how worn it is, but is determined by how deep the hole is. For example......I know by looking at the sparkplugs that are used in our Marauder engines that the threaded holes in the cylinder heads are 24 threads per inch. So if the hole that's being tapped is only a quarter of an inch deep, then there will be 6 threads tapped into that hole regardless of what condition the tap is in that's being used as long as you're using a tap that's made with 24 threads per inch. So as long as the medal where the hole is that's been drilled is one quarter of an inch thick, there will only be 6 threads in that hole as long as the intended tap of 24 threads per inch is used. It would have nothing to do with the tap being "off" as you've implied. And if the wrong tap was used to begin with 9such as one of 20 threads per inch) then the car would've never gone off the assembly line since nobody would've ever been able to thread the intended sparkplug into that hole because the threads would've been different.

Good point.. that is why it was only worth .02.. probably should give back .01... :D

BillyGman

02-24-2005, 09:39 AM

Good point.. that is why it was only worth .02.. probably should give back .01... :D hey, it's all good, because discussions like these help to deepen the understanding of us all about our cars.

metroplex

02-24-2005, 10:25 AM

BillyGman

02-24-2005, 10:31 AM

That's a negative. I'm talking about Timeserts. They're a well known product for repairing ejected spark plug holes on MODULAR heads.

Look it up. They're like helicoil inserts, but they're called Timeserts.got it......I think that different companies who have these products come up with different brand names in order to make their product sound exclusive........."Timeserts"......"slimserts"........

Captain Steve

02-24-2005, 11:09 AM

I can see how the extra threads would help if the tapped out portion of spark plug hole was too high. It's like they tap the whole depth of the hole and then come back and drill from the top to clear it. If they drilled too shallow, then the spark plug would stop where the threads stop, instead of seating on the proper area.

Normal..
| |
| |
| |
| |
| |
|> <|
|> <|
|> <| <-- Threads
|> <|

Threads comming up too high..
| |
| |
| |
|> <|
|> <|
|> <|
|> <|
|> <| <-- Threads
|> <|

http://www.redpulsar.us/~coldfusion/film14/sparkcomparo.jpg
So, you can see that if you put the plug on the left in the bottom hole, it would stop before seating correctly.

metroplex

02-24-2005, 12:11 PM

You're correct, but on the 4.6/5.4 2V heads, your top diagram is how the heads appear.

More threads on the plugs are fine because the taper seats at the same depth.

KilledKenny

02-24-2005, 06:00 PM

Ok, due to a bulb problem with our bore-scope I was only able to do 2 engines.
4.6 DOHC Marauder and 4.6 SOHC Truck
Here is the link http://mysite.verizon.net/killkeny/Sparkpluginfo.zip
There is also a list of usefull stuff about the sparkplugs and numbering system.

BillyGman

02-25-2005, 12:42 AM

Thanks very much. That was very revealing. the marauder cylinder head has only four threads, and the SOHC cylinder head has five threads, and there's a smooth part of the bore immediately following the threads that the original sparkplug design will match up perfectly with. therefore what I suspected is true......the original plugs are better equipped for a perfect fit than these other plugs that have threads all the way up to the tapered shoulder. If you look at that video a few times, it becames obvious that the original plugs will provide a better seal than those other sparkplugs will since they fit the cylinder head hole more precisely. I figured there had to be a reason why Ford called out for the plugs that our Marauders came with from the factory. So as for me, I'm glad that I stayed with that plug design.

metroplex

02-25-2005, 03:05 AM

I figured there had to be a reason why Ford called out for the plugs that our Marauders came with from the factory. So as for me, I'm glad that I stayed with that plug design.

That's funny because Ford calls for AGSF-22FM1 on the 04 Cobra. Unless the heads are radically different between the 03-04 Cobra and the 03-04 Marauder, there should be no difference in sealing between the two different plug designs.

There was a significant concern about the full threaded plugs sealing well on our 4.6/5.4 SOHC heads. Truth be told, if you mic the plugs or use a caliper, you will find that either plug will seal properly on the 2V heads. It just looks like the full threaded plug won't seal.

I recommend you take precise measurements between the plugs to figure things out. A bore scope gives you a good idea of what it looks like, but the only way to tell for sure is to use a caliper or micrometer.

BillyGman

02-25-2005, 01:05 PM

you will find that either plug will seal properly on the 2V heads. It just looks like the full threaded plug won't seal.

That might be the case, but even if it is, I want to reurn to my original point in this thread......which was the fact that since there are merely four or five threads in the sparkplug holes of the Marauder cylinder heads as "Killed Kenny" has proven with his video, then there's absolutely no need, nor advantage by going with those plugs that have more than six threads on them. And there were those who were claiming that there was an advantage earlier in this thread. And that just is NOT true. I'm sure that it was an honest mistake, and that those individuals meant well, but the fact is that having 6 threads on the plugs that are called out for is just fine, and there's no sealing advantages offered by the plugs with 10 threads on them.

hbarrett

02-25-2005, 02:08 PM

I believe that the AGSF-32W-MF6 is a sparkplug for a V6 engine (SABLE AND TAURUS). The 03' and 04' Platinum Marauder plug is AGSF-32W-MF4. At least that is what I see from the Motorcraft online catalog. Is the information incorrect in the online catalog?
Howard

16856 2003 4.6L 4V MUSTANG MACH I, MERCURY MARAUDER, REVISED SPARK PLUG USAGE.
SOME 2003 MERCURY MARAUDER, MUSTANG MACH I, LINCOLN AVIATORS WERE BUILT WITH 4.6L 4V ENGINES USING SPARK PLUG PART NO. (AWSF-32E-M (F6LE-12405-AC) AND
SPARK PLUG PART NO. AGSF-32W-M (XS2E-12405-AB).
WHENEVER THE SPARK PLUGS REQUIRE REPLACEMENT FOR SERVICE, USE PART NO. AGSF-32W-MF6 (XS2E-12405-AB) ALSO, THE REPLACEMENT SPARK PLUGS ARE OF THE FULL THREAD DESIGN AND ARE RECOMMENDED FOR ALL APPLICATIONS. OWNER GUIDE AND SERVICE PUBLICATIONS ARE BEING UPDATED TO REFLECT THIS CHANGE.

My MM came with AWSF-32E-M from the fatory and the full threaded replacement plug is AGSF-32W-MF6.
This would explain why my #7 spark plug gets motor oil around it in the plug hole and fouls the plug. At the factory the counter bore for the plug seat was machined too deep and the plug bottms on the threads before it properly mates with the Cly. head seat.
I see the IT20's have threads all the way up the plug seat so those plugs are all right!
Dennis can you tell us what the cooler plug number with full threads we should use for Motocraft AWSF-A12C?

Thanks!

Dennis Reinhart

02-25-2005, 02:15 PM

MENINBLK

02-25-2005, 02:37 PM

I believe that the AGSF-32W-MF6 is a sparkplug for a V6 engine (SABLE AND TAURUS). The 03' and 04' Platinum Marauder plug is AGSF-32W-MF4. At least that is what I see from the Motorcraft online catalog. Is the information incorrect in the online catalog?
Howard

The F6 or F4 has no bearing on the plug design.
It only dictates if the plugs are packed in a box of 6 (F6) or 4 (F4).
Dealers will probably buy the 6 pack, instead of the 4 pack, just because of the amount of space they have.
One slot for one part.

A Motorcraft Dealer would sell you the AGSF32WMF4 x2 for a Marauder,
and a AGSF32WMF6 for a Sable or Taurus.
If he only carried the F6, he would have to give you 2 loose plugs to make 8...

hbarrett

02-25-2005, 03:35 PM

I see. It make perfect sense. Thanks,
Howard
The F6 or F4 has no bearing on the plug design.
It only dictates if the plugs are packed in a box of 6 (F6) or 4 (F4).
Dealers will probably buy the 6 pack, instead of the 4 pack, just because of the amount of space they have.
One slot for one part.

A Motorcraft Dealer would sell you the AGSF32WMF4 x2 for a Marauder,
and a AGSF32WMF6 for a Sable or Taurus.
If he only carried the F6, he would have to give you 2 loose plugs to make 8...

metroplex

02-25-2005, 08:32 PM

That might be the case, but even if it is, I want to reurn to my original point in this thread......which was the fact that since there are merely four or five threads in the sparkplug holes of the Marauder cylinder heads as "Killed Kenny" has proven with his video, then there's absolutely no need, nor advantage by going with those plugs that have more than six threads on them. And there were those who were claiming that there was an advantage earlier in this thread. And that just is NOT true. I'm sure that it was an honest mistake, and that those individuals meant well, but the fact is that having 6 threads on the plugs that are called out for is just fine, and there's no sealing advantages offered by the plugs with 10 threads on them.

Dennis just said he used the 12Cs on the NA Marauders.

That means the spark plug holes are most likely similar to the 2V holes. The reason I went with AGSF-12FM1 plugs over AWSFA-12C is the longer lasting iridium electrode. I didn't care for the extra threads but they seem to seal just as well as the 12Cs and 32PP (OEM for 00 Vic).

I know this is sound confusing, but I agree that the extra threads have no bearing on preventing plug ejection.
It's just that the 12Cs seem to wear out fast on my Vic.

BillyGman

02-26-2005, 01:16 AM

I agree that the extra threads have no bearing on preventing plug ejection.
It's just that the 12Cs seem to wear out fast on my Vic.
Yes, we're in agreement on that point. And that is precisely why I just changed my sparkplugs after only 13,000 S/Ced miles being put on them. They looked pretty good though, and I probably could've just re-gapped them and put them back in, but I don't really mind changing them once a year since they're only $4 each. To each their own though. ;)

mtnh

02-27-2005, 11:22 AM

I am surprised that nobody has commented on the 12 lb/ft of torque to a angled-seat spark plug. I thought that the proper tightening value was 1/8 turn, or 45 degrees past first contact. I'm not sure what the torque of doing that ends up being, but 12 lb/ft seems low. That could also spell the reason for seeing carbon up inside of all the threads -- air flow! But on only one plug, it sounds more like valve stem oil seal leaks.

One other point would be the protrusion of the new plug design into the combustion chamber as compared to the original. If I got the story right, the orginal plugs do not extend physically into the combustion chamber area, but the electrode is in fact recessed into the plug hole. Is that true?

Mike

metroplex

02-27-2005, 12:06 PM

It's 15 ft-lb for my 2V heads.

BillyGman

02-27-2005, 12:57 PM

. If I got the story right, the orginal plugs do not extend physically into the combustion chamber area, but the electrode is in fact recessed into the plug hole. Is that true?

Mike
That's what was originally being implied in this thread, and that's what I had questioned, and doubted, and after seeing the video of the threaded hole in those Marauder cylinder heads, my suspicions were confirmed, and I think it's obvious that the elctrode on the original plugs are not recessed, and they come right to the end of the threaded hole in the cylinder heads. How do I know that? Because in that video, you can count five threads in the hole, and there are six threads on the original type sparkplugs. The extra four threads on those new fangled sparkplugs do absolutley nothing to secure the plugs in the Marauder cylinder heads. That was my point(and still is).