So I'm putting in new plugs right now...need to gap them to the correct specs.

I've got a couple different gap numbers to go by. My Haynes/Chiltons says .062-.068. Then I've also seen different numbers on different forums. The plugs I bought are Autolite Platinum AP5144. Right now the plugs are gapped at about .048.

So those who have a factory book that says what the gap should be, please post it.

As a reminder...my truck is an '01 4.0L SOHC.

THANKS!!

Shane



EDIT: WHOOPS!! Looks like I'm logged in on my brother's account!!

 

I just put those plugs in mine a few months ago. Initially, the truck ran beautiful, but now is starting to idle rough. Only has about 5,000 miles on them.

Someone told me the wide gap is make them last 100,000 miles. The sticker under my hood said .062-.068. It was recommended to me to go with around.054 and replace them around 40,000 miles. BUT, like I said, I don't like the way the truck idles now, so I will probably pull them this summer and replace with Motorcraft dbl plats.

 

I can't remember if this applies to the 4.0L or not, but the 3.0L specifies double-platinums because one bank is "reverse" firing, tip to electrode instead of electrode to tip.

I can't see a reason to gap them any other way than specified by the decal under the hood.

 

yeah i'd just gap em between .062" and .068". if you much less (like .048" for example) you *might* lose a bit of gas mileage because of a slightly smaller spark/less efficient burn.

 

stock gap on the sohc is ~.065. I changed out my plugs recently and gapped them to .050, I havent noticed any decrease in mileage or performance.

 

well the stock plugs on the 3.0 are .042" to .046"... i originally regapped to .032" with the juice, and noticed about a 1mpg loss. (in my case, probably a combination of the small gap AND the enrichment fuel being added to the n2o injection)

 

I would use the factory recommendations under the hood....

 

ALrighty ya'll....I gapped them to .065 and am throwing them in tonight. And, if I have a bad time with them, I now know how to pull the inner fenders and swap the plugs.....semi-easily.

 

I used the bosch platinum 2's....as in 2 fitted electrodes with zero gaping required. They are absolutely perfect!

 

I installed the Autolite XP5144's @ .065 gap, that was the iridium plug and that turned out to be to much gap for the plug to handle. Another thing was that the reach apparently matched that original Motorcraft plug @ .708" but the Motorcraft plug supposedly had an extended tip and the Autolite does not which I still believe is why they don't seem to hold up as stated in post above as they are running cooler. I then put in the Bosch +2's (4305) and the truck ran good but gas mileage was down. I pulled the plugs after a few weeks and the amount of carbon fouling was unbelievable - only reason that made any sense once again was that they were too cold of a plug. I then ended up with some NGK TR55-IX's, wrong again. Finally NGK TR55-1IX's, let me say that the mileage is back up, power is back up, throttle response is great - very impressive so far to say the least. It runs great! Probably should have just got the Motorcraft plugs from the dealer and called it day looking back. There is so much wrong spark plug info on the Internet for the 4.0L for 01 thru 03 and even 04 it's just stupid.

 

I bought the motor craft wires and plugs and had them put on my ranger.Now it idles too high and has a miss.you can feel it in the steering wheel when setting.I dont like this.anyone have any ideas on this?it's a v6 4.0 2004 4x4 level 11.

 

use the lowest gap listed on your truck sticker...because, spark plugs gaps enlarge over time

 

WHY IS IT SHOWING DIFFERENT SPARK PLUG GAPS FOR THIS MOTOR?I BOUGHT THE MOTORCRAFT PLUGS AND WIRES.IT SHOWS TO GAP THE AT .054

 

.054 would be normal gap for Ranger 4.0l, OHV or SOHC, use that

Slightly larger gap will give better starting and low RPM performance, .059
Smaller gap better high RPM performance, .049

This is the same for all vehicles, Fords gap is the medium for that plug in that engine, it is not possible to gap best low end and best high end, expect to set it in the middle for best over all.

And use double platinum plugs because this is a Waste Spark system, or just use regular plugs, don't use single platinum, waste of money.

Waste spark system fires 2 spark plugs at the same time, 1 spark is wasted, hence the name.
To do this the 2 spark plugs are hooked up in Series wiring, this means one plug will spark from base to tip and the other from tip to base.
This is fine as far as engine operation, except one spark plug will get a worn tip and the other a warn base.
So single platinum will only last longer on one bank of the engine, other bank will wear out just as fast as regular plug, so waste of money.

Get regular plugs if you don't mind changing them more often, or double platinum if you do

 

I had the plugs put in so I assume they rechecked the gap before they put them in.Here is what they say on the JC WHITNEY site,,,,,,,,,
Spark Plug
SKU #: JCW-1074271 Mfr #: SP498
Electrode Tip Material: Platinum
Electrode Core Material: Copper
Reach: 18 mm
Plug Type: Resistor
Heat Range: 1
Thread Size: 14 mm
Gap Size: 0.054 in.
Product Fit: Direct Fit

 

I put s498 in mine 2 weeks ago at 56 gap,in my opinion it's not the rite plug the electrode is big,not a pinpoint in this thread it shows the proper plug with the proper reach, I changed the wires and it idled awsome, put in new sp498 plugs and it idles like crap,just my two cents going back to other plugs

 

get your codes pulled. if it specifies a single cylinder is misfiring, pull that plug. just had to do this on mine (replaced plugs n wires about a week ago) cylinder 1 was misfiring. the porcelain on the plug was cracked. probably was cracked before I installed it and I missed it. just check it real good for cracks.

 

Mine has never threw a code it just idles better with the small electrode plugs that's all

 

4.0l OHV or SOHC models insist on Motorcraft or Autolite(in a pinch) spark plugs, can't tell you why but tried all the brands and that is my anecdote, no scientific evidence.
Other brands either don't last as long or give crappy performance from day 1

 

Thanks ron, do you have a preference on the electrode, my truck runs better with small electrode plugs, don't know why

 

Just replaced all plugs and wires in my 2000 explorer xls 4.0 sohc plug gap set to .055 cause under the hood calls for .054 to .056 used a snap on gapper tool runs amazing now, autolite platinum plugs and just a cheap set of duralast wires gap does differ from sohc to dohc it says in fine print by your belt routing under the hood