4.6L Spark Plugs

[stkelly]

Sorry to start another spark plug thread. But I've searched and can't seem to find the proper gap for a 2008 4.6L.

I've read .45 and .54. I checked my manual and engine bay for a gap and couldn't find a sticker with the information. Ford parts lists sp462 for my vehicle but I heard sp514 was the replacement plug. They are pregapped at .45 from the autoparts store.

Also, how do you gap the motorcraft plugs? I found a gap tool for the plug, but it looks like it will only decrease the gap not increase it. I've also heard that the motorcraft plugs should not be regapped.

So I've read lots of threads, but I can't seem to find the correct consistent information.

Thanks in advance!

 

[Flag Gibby]

For the 4.6L V8 engine the gap is 0.45 and for the 4.0L V6 engine it is 0.54. So any correct plug for the 4.6L from Motorcraft, NGK, etc. will already be pregapped at 0.45 and you only need to verify the gap before installing.
The problem with the sp462 plug is the copper coating on the threads that allowed it to sieze in the heads so Ford changed to a nickel coating and relabeled the part number to sp514 (both plugs are a 2 piece design). Both plugs are the correct part for your engine, and both need antisieze on the threads when installing.

 

[stkelly]

Thanks for the info!

 

[jseabolt]

Sorry to start another spark plug thread. But I've searched and can't seem to find the proper gap for a 2008 4.6L.

I've read .45 and .54. I checked my manual and engine bay for a gap and couldn't find a sticker with the information. Ford parts lists sp462 for my vehicle but I heard sp514 was the replacement plug. They are pregapped at .45 from the autoparts store.

Also, how do you gap the motorcraft plugs? I found a gap tool for the plug, but it looks like it will only decrease the gap not increase it. I've also heard that the motorcraft plugs should not be regapped.

So I've read lots of threads, but I can't seem to find the correct consistent information.

Thanks in advance!

Unless you are using a typical style sparkplug, I did not think the gap could be adjusted because of the way they were made.

These things are way overpriced. $13 a piece.

By the way, after installing new plugs, my '06 Explorer ran worse! Turned out Motorcraft made a defective spark plug and I got one of them.

I have never encountered a faulty spark plug in all my yearsof buying plugs. At $13 a piece these things should be guaranteed to be good right out of the box.

 

[stkelly]

I ordered a set of plugs on ebay. One was off by a little .40 vs .45. I hope it doesn't make much of a difference because I definitely can't adjust it. Not sure why Ford went to this type of plug, the old single arm plugs worked fine in all of my previous cars/trucks.