sseiyah

2007 F150 with the 4.6...

I have a misfire on cyl7 which likely means those original 125k coils are probably on their last legs. It seems like a fairly common problem with Fords. I ordered a set of 8 Accel coils which seem to be decent. Looking at the engine they are pretty damn close to the fuel rails. I'm wondering if removing the fuel rails is required. I know the coils should be fairly flexible but wondering if its worth my time to get the fuel rails/injectors out of the way first?

sigmanf150

Removing the fuel rail is unnecessary. The boots are flexible and will allow deflection when removing/installing them. Don't forget to blow out the spark plug wells with compressed air.

homer

x2, even during plug change I never had to pull the fuel rails.


I fully agree with sigmanf150 on the compressed air. *IF* you change the plugs just keep in mind the breaking plug issue (depending the date of your engine and assuming you didn't know)

Bossgame

Can anyone settle this dispute? I read somewhere, don't remember where, that the 2 valve heads in these 4.6's do not have the spark plug breakage issues, it is only the 3 valve heads that have it. I believe it said something about a different plug being used. Any validity to this?

gone postal

The 2V 4.6 doesn't have issues with plugs breaking. They do, however, tend to have the threads strip out of the heads, but that's an easy fix if it does happen.

truck-king80

Knock on wood I didn't have a problem pulling a plug with a warm engine. It was the best advice someone told me so I'm just passing the word

Summers22

iTrader: (2)

Same here, 113K, warm engine, 5.4, no broken plugs.

OP, fuel rail does to to be removed, especially for COP change.....

gone postal

Before you guys send someone down the primrose path:

1) It's a 4.6L. Completely different animal from a 5.4L

2) The fuel rail DOES NOT need to be removed.

3) Plugs breaking is an issue unique to the 5.4L 3V engine. The 4.6L has other issues with the plugs, as mentioned above (stripping threads, ejecting plugs) but breakage and difficulty removing them from the carbon buildup on the plugs aren't issues to worry about with a 4.6L.

Summers22

iTrader: (2)

He needs to change the plugs as well, especially at 125K. If on a 4.6, yes, other issues persist with the heads. Neither engine needs fuel rails pulled.