Hey,

Tomorrow I'm changing my plugs. I've got the 4.2L V6 for an engine and I went to Canadian Tire and checked the book it said listed NGK G-Power plugs with stock number 3668. I picked those up. Looked at the website and it gave a different stock number, looked at another NGK website and it also gave another stock number.

I have NGK GPower: TR55-1GP 3668 verified that it is the 0.54 gap.... Are they good to go?? I don't wanna blow the engine.

 

The 4.2Ls really don't like anything except stock Motorcraft SP-504s gapped to .054"

 

X2 get some Motorcraft plugs.

 

autolite is going to be cheaper and they are identical to the moto's. go with the autolite AP5144 im running them and at 2.99 they do the job nicely

 

X4, these motors are picky when it comes to plugs. I tried Bosch and they sucked, truck ran so rough I thought it would shake apart. I've run Autolite and Motorcraft only and had no issues. Just gap them to 0.054" and you are good.

 

Motocraft isn't offered around here. Already purchased the NGK pre gapped to 0.54; safe to go ahead? Maybe I should have a shop do it just incase there are problems?

 

Just double check the gap, 0.054" not 0.54". Always check the gap on new plugs, even if they say pregapped. You can get a feeler gauge pretty cheap and gap them yourself.

 

Alright thanks for your input guys. I changed the plugs yesterday myself after a good lunch at school haha. The plugs were pretty burnt, I'll be uploading a picture tonight. Previous plugs were Bosch.

I threw in the NGK and the truck runs a lot better now. Before I was experiencing a slight misfire/hesitation when trying to accelerate slowly from coasting speeds, and last night I drove the truck pretty long and pretty hard and noticed a slight performance increase even in the shifting and snappiness of the throttle response. Think the burnt plus could've been the culprit? Another thing is I've got the service engine soon code, it's been there since June when I bought the truck and I ran it on the code reader. I guess bank 1&2 were running too lean... That's where the worst plugs came from, any chance this is why??

 

Only the codes can answer that. Have you gotten the codes read, or reset the light?

 

I honestly don't know how to reset the light but I do have a code reader at school that I can use. I've read the codes and all they said was "Bank 1 running too lean" "Bank 2 running too lean".

Tomorrow I'll read them again and clear it. I've also got a code regarding the EGR...

 

Another thing I'd like to mention since the change, I feel acceleration smoother and more responsive but I feel like there isn't the compression there once was.. Could it be due to a loose plug? If so, is it something to be worried about?

 

Yea if a plug is loose thats not good. What did you torque them to? The spec is 84 to 168 in-lbs. Now to clear up any confusion that is in inch pounds not foot pounds. I know inch pound wrenches are hard to come by. So you could convert the 84 and 168 to ft lbs. Im not sure what that would be. But there are conversion tables that can be used for that.

 

An easy search would give the answer to the recommended torque on this Forum. See post #4.......... https://www.f150online.com/forums/19...ark-plugs.html

I trust the folks on here to help me avoid a blow out so, I for one, follow this answer. And yes.... a loose plug is just asking for a disaster.