Awelch

The owners manual for my 99 Taurus <engine code u> says cylinders 1,2,3
use plugs with suffix "PG" but cylinders 4,5,6 have plugs suffix "P".
CAN ANYONE EXPLAIN? The guide for Autolite plugs says Double platinum
plugs APP&^$ are used in this engine. Will I be OK with those?

Paul of Dayon

Perfectly OK. When they build the engine they use platinum plugs almost
like the aftermarket ones. Aftermarket plugs are platinum plated on both
the point and electrode but half the originals are plated on one only. We
assume this cuts costs a bit on the big scale but for replacements, it would
likely cost more to supply both so we can only get the ones that have both
sides plated. Something about the electrical characteristics of the spark
transferring metal. Use the double platinum plugs, the one side is just
getting a slightly better plug than specified.

Hope this Helps

PoD




"Awelch" <bozo2@ticon.net> wrote in message
news:43a07781$0$1765$8b463f8a@news.nationwide.net...
> The owners manual for my 99 Taurus <engine code u> says cylinders 1,2,3
> use plugs with suffix "PG" but cylinders 4,5,6 have plugs suffix "P".
> CAN ANYONE EXPLAIN? The guide for Autolite plugs says Double platinum
> plugs APP&^$ are used in this engine. Will I be OK with those?

CJB

Double platinum is just fine. I think what Ford did is save a bit of money
on spark plugs. My understanding is that some of the plugs fire from center
electrode to ground, while others of the plugs fire the opposite way due to
the fact that some get +voltage, and some get -voltage. Where the platinum
needs to be depends on which direction the spark is traveling. Ford,
therefore, saved half on platinum by only putting it where it has to be.

If you get plugs with platinum at both ends of the gap, you're literally
covered either way.

CJB


"Awelch" <bozo2@ticon.net> wrote in message
news:43a07781$0$1765$8b463f8a@news.nationwide.net...
> The owners manual for my 99 Taurus <engine code u> says cylinders 1,2,3
> use plugs with suffix "PG" but cylinders 4,5,6 have plugs suffix "P".
> CAN ANYONE EXPLAIN? The guide for Autolite plugs says Double platinum
> plugs APP&^$ are used in this engine. Will I be OK with those?

trainfan1

Awelch wrote:
> The owners manual for my 99 Taurus <engine code u> says cylinders 1,2,3
> use plugs with suffix "PG"

Platinum Ground electrode

but cylinders 4,5,6 have plugs suffix "P".

Platinum center electrode

> CAN ANYONE EXPLAIN?

Different potential biasing in the high tension spark circuits - one
ground to center, the other center to ground.

The guide for Autolite plugs says Double platinum
> plugs APP&^$ are used in this engine. Will I be OK with those?

Perfect. Stick with Autolites and you will be "blessed".

My question though - do you really have enough miles to need a plug change?

Rob

Big Al

"trainfan1" <lmsearing@usdatanet.net> wrote in message
news:coudnYQII6Y5Uj3enZ2dnUVZ_sWdnZ2d@usadatanet.net...
> Awelch wrote:
> > The owners manual for my 99 Taurus <engine code u> says cylinders 1,2,3
> > use plugs with suffix "PG"
>
> Platinum Ground electrode
>
> but cylinders 4,5,6 have plugs suffix "P".
>
> Platinum center electrode
>
> > CAN ANYONE EXPLAIN?
>
> Different potential biasing in the high tension spark circuits - one
> ground to center, the other center to ground.
>
> The guide for Autolite plugs says Double platinum
> > plugs APP&^$ are used in this engine. Will I be OK with those?
>
> Perfect. Stick with Autolites and you will be "blessed".
>
> My question though - do you really have enough miles to need a plug
change?
>
> Rob

One bank has normal spark polarity, the other bank is reversed. Rob hit it
right:)

Al

Backyard Mechanic

"Big Al" <sal1@qwest.net> wrote:

>
> "trainfan1" <lmsearing@usdatanet.net> wrote in message
> news:coudnYQII6Y5Uj3enZ2dnUVZ_sWdnZ2d@usadatanet.net...
>> Awelch wrote:
>> > The owners manual for my 99 Taurus <engine code u> says cylinders
>> > 1,2,3 use plugs with suffix "PG"
>>
>> Platinum Ground electrode
>>
>> but cylinders 4,5,6 have plugs suffix "P".
>>
>> Platinum center electrode
>>
>> > CAN ANYONE EXPLAIN?
>>
>> Different potential biasing in the high tension spark circuits - one
>> ground to center, the other center to ground.
>>
>> The guide for Autolite plugs says Double platinum
>> > plugs APP&^$ are used in this engine. Will I be OK with those?
>>
>> Perfect. Stick with Autolites and you will be "blessed".
>>
>> My question though - do you really have enough miles to need a plug
> change?
>>

Sounds right if he's a long distance commuter

> One bank has normal spark polarity, the other bank is reversed. Rob
> hit it right:)

To further illuminate:

Count the coil packs, note you have 1 per each 2 cyls... unlike the
legacy ign systems where one side of secondary (Hi-V) connected directly
to ground, each coil fires once per rev and is wired:

Gnd --plug A -- coil neg &&& coil pos -- Plug B -- Gnd

Thus both plugs are fired on each trigger


--
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!