This has been bugging me for a while now..

I have a 2002 Edge with the 3.0 Vulcan

About a month ago I did a tune-up on my ranger and I was quite disturbed.. I changed the plugs and wires and was shocked to find that the plugs were very badly worn and some of the ceramic material was cracked on the plugs. That wasn't the worst part, the plugs in the left bank were not the same as the plugs from the right bank...

I don't mean they were the same style but different numbers, I mean they weren't even the same size or material... The left bank was platinum and the right bank was ordinary plugs.. I'm a Part Sales Manager for my local Autozone here in my town, I work with parts all day so I know two different plugs when I see them. Also; my truck only had 12,865 miles on it when I did this.... I couldn't figure out why the plugs were cracked....

Has anyone else run into a problem like this?? Have you had the original plugs be different?? I called the Dealership that I bought the truck from and they had no explanation for it and said that they would have to see the plugs for themselves. So I brought them up to them and showed them and they just said that it wasn't a big deal and saw no problem...

 

don't know why they would be cracked, but as for diff. numbers, the polarity is reversed - left bank vs. right bank. when replacing it's best to use double platnum plugs, then polarity isn't an issue. I may not have all the terminology correct, but I think you get the idea of what I'm trying to say. possibly someone with more knowledge will chime in.

 

Your insulators should not be cracked but it is not related to the two different spark plugs.

The plugs in the right and left banks are different because each pair of plugs shares a coil in the triple coil pack. The current flow through the DS bank of cylinders is opposite that of the PS bank. Look again at the electrodes and you will see that the plugs from one bank have the platinum nub on the center electrode and the other bank's plugs have it on the side electrode. The platinum is there to prevent electrode erosion, so its position is determined by the current flow through the plug.

Using the two different single platinum plugs saves a very small amount of money on each plug during original production that adds up when building so many engines.

The replacement plugs have platinum on both electrodes (double platinum) to revent installation errors during field service - one plug is correct for all 6 cylinders.

 

I have heard of ways to save money on each car and it makes sense $1 a car time a million cars is a million dallors saved, but man thats a new one.

So stock plugs are all single platium but on side has the platinum on the center electrode and the other has the platinum on the side electrode, man talk about counting your pennies. but whatever works i guess.

 

Are you sure about this? Does the Owner's Manual address this and tell you what to use for replacement plugs? (I don't have access to my Owner's Manual at the moment.)

 

I went to O'Reilly and they told me that the OEM plugs were double platinum. Then they told me that they only had four in stock. yea. Then they told me that their warehouse is under 4 feet of water. double yea.

 

Yeah they're right about the whole plug thing. When I worked for Ford we just replaced them with a double platinum plug though. The single platinum saves them like 3 dollars a truck which is a whole hell of a lot.

 

Yes and yes, assuming that we are talking about the 3.0L Vulcan as in this thread's original post. The bank-specific, original equipment single platinum plugs (P or PG) are not available as replacements. The manual tells you to use double plats (PP) and gives a number. This is true of many Fords with EDIS.

4.0L SOHC's have the same plugs right and left side from the factory. These are FP series plugs which the Motorcraft site calls "finewire" platinum. They are all the same part number, original or replacement, right or left bank.

 

Thanks Bob.

 

Honestly, I checked the computer again at work and it said that the OEM plugs were double platinum..

When I changed the plugs I just put 6 Autolite Dbl Platinum's in and the truck runs great.. I just didn't understand why they looked so bad after only 12K+ miles..

But the odd thing about it all, is the Ford Service Manual talks about how the plugs are not the same from left to right bank.. It does however say that the best replacement is DBL Platinum all around though... Interesting..

 

I may never know what the 6th plug looks like on my 4.0 SOHC engine

 

Since I haven't had the chance to get up close and personal with a 4.0 SOHC ranger motor.. Are the plugs and wires that hard to change?

 

The two rear plugs on the passenger side are tight. It is easiest to pull the PS tire/wheel, remove the rubber splash shield (easy) and access the PS plugs through the wheel well.

 

OUCH!!


For you 4.0L Owners out there, my apologies.. That sucks!!

I thought burning my forearm on the manifold every oil change was bad, damn..

I think I am glad I have a 3.0L..

 

If you go in through the wheel well, swapping out the plugs is not difficult and you only have to change platinums every 50K+ miles. Try installing headers on a 4.0L. That's a real treat.