outceltj

The first two threads are missing like it was backed out and then shot out

Tberg725

Yeah its weird, ive never seen this happen before, im going to change out the plugs in the spring sense the car is going to be sitting all winter just have to decide now which plugs to buy

Rudolph Hucker

overtightened plugs..semi stripped thread that popped out

Tberg725

This is the second time that I have heard that over tightening plugs can cause them to pop out, I've only put 9,000 miles on the car sense I bought it from the dealership so I've never looked at the plugs, guess it was one of them things about the newer mustangs that I knew nothing about.

Derf00

The heads are aluminum and while light weight, they do not have the strength of steel. When you over tighten the plugs, the threads on the head become weakened over several heating cycles from the pulling of the threads. The plug body is steel, the head is aluminum...guess which one loses?

akdoggie

I hate to say this, but it is a very common thing in the Ford 3v 5.4 engines. Usually at high miles, or after a number (3 or more) spark plug changes. I own a 98 4.6 and don't have the problem with that, but the newer 4.6 have PI head, which give more flow, but the thread area isn't as strong as the earlier 2v or 4v heads. This is why the 3v 4.6's blow plugs. That and over tightening the plugs when installing them. Twenty eight (28) pounds is all they use. Anything more is just asking for trouble.

Lisle makes a special tool for these broken plugs and a thread repairing kit. 65600 is the part number for the broken plug remover. OTC makes a special spark plug tool for the 3v also, so that there is NO flex are the connection joint on the plug tool. It is a one piece 9/16 socketed tool. When in comes to fixing the threads, there are numerous kits out there. Do NOT use one of the cheap kits or you will have the problem again, only the head will probably have to be removed the next time, if it blows again on the same hole. Use Time Sert inserts if you can. They are the best and most reliable on the market. Of course, they are probably the most expensive. The kit is the big price, but you can keep it for another time, or resell it to another member. Just don't use the cheapos. They will last no time at all, and they are just that, cheap crap.

Go online and check out the head repair on the 5.4's. These 4.6 heads are just like them. YouTube has a bunch of videos on this happening. The F150 forums are full of spark plug blow out horror stories. They aren't that bad to fix, just a bit time consuming and can be a bit expensive. You might be able to rent the tool from a tool rental shop, but that depends on where you are. I'm sure Advanced isn't going to have it for a loaner, but you could check. That would be the ticket if they did.

Hope that helps clear up the plug question.

moosestang

I certainly hope he unplugged that injector!

moosestang

I haven't heard that, but it certainly possible to pull the threads out by over tightening. I always torque mine to 25 ft lbs and not one problem.

Tberg725

thanks for your input ak

white08gt

where is the rest of the spark plug? electrode? ceramic piece?