What is the procedure for changing plugs in the 4.6. Is it the same as the 5.4

 

Forgot to mention I have a 2001 supercrew /4.6,73,000 mi with a bad shudder or miss when excelerating.

 

I have a '97 F150 with a 4.6l. I have done the plug change twice; pain in the ***, but do-able if you're patient and don't mind bloody knuckles.

The biggest difference between the plug change on the 5.4l and the 4.6l is that the 4.6l has no coil packs over the plugs (a good thing) and has plug wires (a bad thing). Unless they've changed the 4.6l to coil packs like the 5.4l, you'll find the 4.6l has a coil for each bank of cylinders.

The plugs are recessed into the heads at least 3", so you're flying blind; you'll need lots of various size extensions, universal joints, duct tape (to hold the extensions together), and a plug socket with a rubber insert to avoid breaking the plug ceramic when installing/removing.

Plugs on driver's side slanted toward vehicle front; passenger side plugs slanted toward rear, making the pass. rear plug a real SOB to install/remove.

You really don't have to remove any fuel rails, but unplugging the injector connections may help; also moving the power steering pump out of the way may also help (easy to do).

I recommend you replace the plug wires at your mileage (get a "good set;" will run you at least $60, but worth it. Your miss may be a bad wire or a fouled plug.

Use dialectic grease on inside of plug boots or boots will be VERY difficult to remove next time you do this job.

Use air to blow out plug holes after they are removed from the head.

Have plenty of beer handy and take your time.

 

jaymz:

2 things, you should blow the plug holes before you remove the plug so the dirt in the head don't fall into the cylinder, and put antiseize on the plug threads so it's easier on your nuckles and heads the next time around.

That job is a pain in the *** isn't it?

 

Harleyd1:

Yup, right on both counts. Although I've never had trouble removing the plugs on my 4.6l, I always use some Locktite anti-seize on the plug threads cuz of the old "dissimilar metals" theory.

 

4.6 is coil on plug

 

'97s weren't. What year did they change them?

 

I have a 98 with plug wires. Two coil packs, 4 cylinders per coil.

I would guess 99 or 2000 they changed 4.6 to the coil on plug type.

 

My 99 has 2 coil packs. Also, note that the plugs are different for the 5.4 and 4.6. If you get OEM's there will be 4 plugs of each of 2 different part numbers. Otherwise you can use aftermarket double platinums.

 

My 2000 is coil on plug

 

I noticed when I removed the plugs from my engine there were two different plug types in each cylinder bank. I went to the manual and it listed 1 type for replacement, I confermed this with the dealer. They couldn't give me details, they just said that's what the factory puts in.

I replaced them with FordMotorcraft double plat., not from the dealer though, they wanted $9 per plug, Autozone $3.

This is on a 4.6.

 

My '99 manual says that the part number for the 4.6L plugs are AWSF32PP 4with a PG suffix and 4 with a P suffix. Look closely at the table in the manual (if it's a 99). There are 3 asterisks indicating a note which references t different suffixes. My understanding is that half the plugs fire from electrode to ground and the other half fire in the opposite direction. So, the 2 plugs types indicate where the platinum is, just the electrode or electrode and ground. That's why double plats would work for both. There were some interesting responses to a thread I started on this issue late in August. The thread title was Spark Plug Curiosity. You can search it if intrested.