Tune-Ups: Spark Plugs

[SinCity R/T]

What many people have recommended for use in the 3.9L V6, 5.2L V8, and 5.9L V8 motors is the Autolite 3923 spark plug. This plug is a little shorter and one heat range colder than stock, which helps prevent detonation which can be common with the OEM "beer barrel" style manifold.

Stick with the $.99 copper variety of plug, the expensive split-fire, platinum-tip, etc. type of plugs tend to run hotter than stock, which can be beneficial to other vehicles but not Magnum V8 motors.

[SinCity R/T]

The standard pushrod Magnum V8 motors come with metal spark plug heat shields that surround the spark plug and help protect them from heat. Many owners feel that these spark plug shields are unnecessary with regular maintenance, and tend to trap water and dirt next to the plugs which increases the likelihood that they will rust onto the block.

Many people end up removing these spark plug shields - remove the spark plug wires so you don't damage them, grab onto a shield with a sturdy pair of pliers, and wiggle them out - takes a bit of elbow grease.

[SinCity R/T]

Any time you change your spark plugs, with or without the heat shields, it is recommended that you use a can of compressed air (designed for cleaning computer keyboards/etc.) to blow debris away from around the spark plug BEFORE you remove the spark plug from the block. This helps prevent dirt and other crud from falling into the head when you are changing spark plugs. You can usually buy a 3-pack of cans for under $10 from stores like Best Buy, Fry's Electronics, etc.

[KREWZER]

The standard pushrod Magnum V8 motors come with metal spark plug heat shields that surround the spark plug and help protect them from heat. Many owners feel that these spark plug shields are unnecessary with regular maintenance, and tend to trap water and dirt next to the plugs which increases the likelihood that they will rust onto the block.

Many people end up removing these spark plug shields - remove the spark plug wires so you don't damage them, grab onto a shield with a sturdy pair of pliers, and wiggle them out - takes a bit of elbow grease.

wow, i always thought those things were ugly, but didnt know they came out that easy...amazing :clap2:

[ck98daksport]

so you're saying that if i remove the heat shields there's no problems? I always hated those things but on another forum I asked the same question and the response that i got was that the shields are on there for a reason and not to remove them. Is this shield removal just for the magnum v-8s or is it allright for the magnum v-6s too? Sorry for all the questions, just want to be 100% sure before I go tearing off parts.

[swedish_dakota]

I had recently changed the plugs on my '98 3.9 v6 to bosch platinum 4's...I haven't had any problems with them before, but I am guessing that the v6 has a similar beer barrel style system?

[swedish_dakota]

as for the heat shields, mine for the most part are just dangling there....

[99durango318]

Screw those heat shields, they look nasty from corrosion after a whiel, i took mine off

[grey ghost]

how do the little black boxes on the spark plugs come off?

[99durango318]

how do the little black boxes on the spark plugs come off?


what little black boxes? U sure your looking at the spark plugs? Your not looking at the spark plug wire boot are you?

[grey ghost]

not sure they are just little black boxes on top of the spark plugs they may be the boots.

[N56629]

not sure they are just little black boxes on top of the spark plugs they may be the boots.

do you have a 3.7 or a 4.7?

[99durango318]

If its on top of the spark plug, you should be able to remove what ever it is by twisting it a few times and pulling on it....But make sure your looking at the correct thing, dont wanna just twist and pull on anything under the hood :biggthump

[Aaron001]

does it help at all to remove them on a 4.7?

[whitedak99]

so you're saying that if i remove the heat shields there's no problems? I always hated those things but on another forum I asked the same question and the response that i got was that the shields are on there for a reason and not to remove them. Is this shield removal just for the magnum v-8s or is it allright for the magnum v-6s too? Sorry for all the questions, just want to be 100% sure before I go tearing off parts.


Just think of the V6 as a V8 with the last two cylinders cutoff, they are the same. As far as the shields.......pull those sumbleaches out :banana2:

Later
Chris

[DrPepper]

the box on top of each 4.7 plug is the ignition coil for that cylinder, and it is bolted to the engine. So, twisting it would NOT be a good idea. This thread and the heat shields only apply to the 3.9, 5.2 and 5.9 engines.

The heat shields may be ugly (I think so too) but I wonder about the stock wires holding up to the exhaust heat. Aftermarket wires with a good high temperature end probably won't have a problem.

[grey ghost]

I have a 4.7 :drive:

[Miikal]

For the 3.9 V6, whats the correct gap to set the 3923 at?

[WentInsane]

For the 3.9 V6, whats the correct gap to set the 3923 at?
I think that the gap for 3.9's/5.2's is .035" If I am not mistaken. The label under hood should tell you what the recommended gap is.

[RunninDual00]

Last night i replaced all of the sprak plugs in my car except for the one that was hard to get to (it was getting cold), and i didnt gap them, they were the kind that fit my truck from autozone (autolite platinums... should i go back and gap them? im really ot even sure what gapping is, oh and i got a set of autolite platinum spark plug wires, is there anything else i should worry about doing? I really hope drving today hasnt messed with the timing and pistons and all that, the truck sounds like its running fine though..
Thanks
Matt

[Yellow318]

Last night i replaced all of the sprak plugs in my car except for the one that was hard to get to (it was getting cold), and i didnt gap them, they were the kind that fit my truck from autozone (autolite platinums... should i go back and gap them? im really ot even sure what gapping is, oh and i got a set of autolite platinum spark plug wires, is there anything else i should worry about doing? I really hope drving today hasnt messed with the timing and pistons and all that, the truck sounds like its running fine though..
Thanks
Matt


I would probally go back and gap them. The gap is .040 if you needed to know that.

[RunninDual00]

I would probally go back and gap them. The gap is .040 if you needed to know that.
How do you gap?

[Yellow318]

How do you gap?

Go to a parts store and ask them for a spark plug gapping tool. It is round and has the number on it. All you do is slip it in between the gap in the spark plug and turn it to the correct number, which is in your case .040 which will be marked. If it is gapped too far just bump the end of the plug till you can regap it at the correct gap. Just tell me if I confuse you. It is pretty simple you will see. They only cost like 50 cent to like $1 and the go good on a keychain that is where mine is. I hope that helps you out some. Oh and when you properly gap your plugs you ll noice better throttle response.

[RunninDual00]

Go to a parts store and ask them for a spark plug gapping tool. It is round and has the number on it. All you do is slip it in between the gap in the spark plug and turn it to the correct number, which is in your case .040 which will be marked. If it is gapped too far just bump the end of the plug till you can regap it at the correct gap. Just tell me if I confuse you. It is pretty simple you will see. They only cost like 50 cent to like $1 and the go good on a keychain that is where mine is. I hope that helps you out some. Oh and when you properly gap your plugs you ll noice better throttle response.
Thanks, it wont riding around for a few days without it ungapped with it?

[GoFastGray]

Thanks, it wont riding around for a few days without it ungapped with it?
Just make sure you check them...a few days will be fine. But gap them asap!! I changed my plugs to autolite 3923's not too long ago and they were allready gapped to about 39-42. some i had to bearly hit the wire closer, and some i had to wedge the gap tool in just a bit. I would make sure to gap them though cause they're not always acurate or sometimes not close to .040
And make sure you get the hard to reach ones, i had to take my air intake out and that made it cake to get to the back passenger side plugs :biggthump

[wreckless123]

Good info, thanks..

[dakotadriver360]

where's the best place to find the Autolite 3923s? I tried the local Autozone today with no luck.

[wreckless123]

where's the best place to find the Autolite 3923s? I tried the local Autozone today with no luck.

Advance Autoparts had they yesterday for $1.50 each.. :onethumb:

[GoFastGray]

where's the best place to find the Autolite 3923s? I tried the local Autozone today with no luck.
walmart... $1.99 for two :mullet:

[GoFastGray]

walmart... $1.99 for two :mullet:
or it was $3.99 for four....? :jester:

[5.9 R/T]

Are these the plugs you are talking about???
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FRM%2D3923&N=700+115&autoview=sku

[aspen79]

My 3.9L has the shields, and I assume they are there to keep the plug boots from getting cooked. When you think about it, the older 318, 360 never had them with no problems. As whitedak said, the V-6 looks exactly like a V-8 without two cylinders. In fact, the front cover, water pump, brackets, rockers, etc are all the same regardless if it's a 3.9 or 5.2L.

[Ryknow86]

ghost, do you have a 4.7, if i remember correctly the 4.7s had the coil on plug setup, maybe those are the black boxes your thinkin of.