nyknicks8

I have a 2003 4.6L with 85K miles with original spark plugs. I was planning on changing them but I am now afraid of the plugs blowing out after reading all the stories. The car is running fine so far and this is my only car. I bought the plugs, socket and torque wrench but now I'm thinking of returning everything and not take a chance.
What would you guys do?

proeagles

I'd bite the bullet and take it to my local Ford dealer. If a plug does break then you are SOL and spending even more money to get it fixed or buy the repair tool and learn to do it yourself.

Derf00

Different issues between the 4.6L 2V found in 95-2004 mustangs and the 4.6L 3v found in 2005-to early 2008 Mustangs.

The OP is referring to the spark plug blow out that occurs in the 2V engine. It has to do with the number of threads the plugs use to hold onto the head and how they sometimes literally get blown out of the head and thus strip the threads in the head. The cheap repair is a heli-coil. The more expensive is a thread insert after tapping the head to put it in. They are slightly different. 2V 4.6L engines use a one-piece plug and don't have issues with breaking the plug physically.

What you're refering to ProEagle is the two piece spark plug design of the 3V 4.6L where you can physically break the plug trying to remove it from the head. Our plugs don't blow out, they break when trying to remove them.

Z28KLR

It's a seriously easy job, don't puss out. A swivel extension will be extremely helpful for removing and installing at #4. DON'T overtighten, that's where people get problems. Thin coat of anti-seize on the threads and tighten to 11-14 lb/ft.

proeagles

I did say break in any event whether it is trying to get them out or blow out. In his case he is trying to get them out. If he is a novice and the plugs have been in there for a long time, then chances are he will have a failure which he will regret. I'm not a big fan of going so long on plug changes even though they can go 100K miles now. They were not put in with antisieze from the factory in the first place and dissimilar metals don't like each other for very long.

nyknicks8

Thanks I’ll do it next week. If you used motorcraft SP-493 plugs were they pregapped correctly? Mine seemed to be all tapped around 0.050 rather than the 0.052-0.056 spec. I’m ordering another gap tool to make sure mine is accurate.

Z28KLR

I always check and set gap as necessary. .050" won't cause any problems, but yeah shoot for about .054". Just one of those round $2 gap tools from your local parts store is all you need.

nyknicks8

Thanks, I ended up buying two gap tools to ensure accuracy and the pregap was around 0.050 so I increased it to 0.052-0.054.
Had no issues with replacing them. It seemed that two of the old plugs were looser than the others when removing.
I'll just have to recheck them in a couple hundred miles to ensure they didn't loosen. My biggest concern is the blow out.