I am planning on changing the spark plug and wires on our 1996 Ford Explorer tomorrow (Sunday). It has the 4.0L V6 engine. I've searched this forum and read some previous threads about changing the plugs, and here's what I've come up with:

-Use anti-seize lubricant on the new plugs before installing them.
-Put the vehicle up on jack stands, remove the passenger side wheel, and there's a panel that comes out making it easier to get to the plugs on that side from the wheel well instead of from up top.
-May be easier removing the wires if I use a spark plug wire puller.
-Change the plugs and wires one at a time.

Anything else I'm missing? Am I going to have to remove any other parts to get to any of the plugs? The plugs on the driver's side don't look too difficult to get to...the passenger side plugs look like a chore, but I'm hoping they'll be a lot easier through the wheel well.

I'm planning on purchasing Autolite wires - any recommendation between the Pro-Fit series or the Professional series? The Professional series is only $4 more, so I'm planning on buying those unless there's a good reason not to.

Plugs - looking at either the Motorcraft AGSF42FMF6 from my dealer for $6.90 a plug, or the Autolite APP765 from Advance Auto Parts for $3.97 a plug. If I have enough money I'll get the Motorcrafts, but I may only be able to afford the Autolite's - I'm a bit short on money right now.

If anybody has any additional advice to offer I'd appreciate it.

 

One other suggestion.... check the gap on the new plugs. Never trust that they are already gapped correctly no matter what the manufacturer or salesperson says.

 

I have another question also -

We purchased this Explorer used a few years ago. It has just shy of 150,000 miles on it now. I don't remember off-hand, but I think we've put around 35,000-40,000 miles on it since we bought it. I have no idea when the spark plugs were last changed. For that matter I don't even know for sure they ever were changed - I hope they were! (I should have changed the plugs shortly after we bought it....but I didn't, and I can't go back and do it now.) Anyway, because I don't know, I'm trying to anticipate the possibility that one or more plugs may be seized in there. If this does happen, is there any harm in leaving the seized plug(s) in there, but replacing all of the others? For example, having 4 new plugs that are gapped properly, coupled with 2 old plugs that are presumable gapped too large because of their usage...would that cause any drivability problems, or damage to anything?

 

I had that happen and you surely do not want to over torque the plugs trying to remove them. Spray them with liquid wrench or something similar and be patient. You can shear it off in the head. Mine took 3 days of hammering with an electric impact wrench and frequent bathing with liquid wrench. It finally came out and I was able to re-install new ones with anti-seize. Let's hope you have better luck.

 

I quess you can leave a plug in if you have to providing you don't break the insulator when you are trying to get it out. But if you take your time, and use the correct socket extensions, you should be able to get the old ones out. Start with the drivers side since it's easier. That way you will get use to the angle of the plugs and the feel of them coming out.

 

Thanks everyone for your advice! I got all 6 of the plugs and wires replaced.

After pulling the old plugs out I know now that they probably didn't need to be replaced. They must have been replaced shortly before we purchased the Explorer. The old plugs were still in excellent condition - I checked the gaps and they were all between 0.050 and 0.054, which I found slightly odd as I thought they were supposed to be installed at 0.054...but anyway, that's what they were at. All of the plugs came out extremely easy as well, after breaking them loose, which also was not hard. My fears of a seized plug thankfully did not happen.

The spark plug boot puller also made a huge difference! The store I bought the plugs at didn't have any in stock so I unwisely decided to start changing the plugs without it. The first boot pulled off easily. The second one was another matter - after wrestling with it for 20 minutes or so I gave up and went to a different store on the other side of town and bought a boot puller there. I got the boot off within 20 seconds with that! It makes a huge difference, especially in those hard to reach areas.

 

Glad it worked out... I suspect the gap on the old plugs included some residual build up..

 

Yeah, that's probably what it was. That never occurred to me.

 

I see a lot of people replacing plugs that don't need replacing. If your milage is still decent and it starts good,leave it em alone! I see most of the problems start AFTER the plugs are replaced.
Todays spark plugs are built to go the distance with todays unleaded gas. Be sure you have a problem before you waste money on new plugs. IF you feel you HAVE to have new ones in there,use the exact same brand,and numbers.
Read through the forums and notice how many have problems AFTER they do the change because they try some other brand or heat range.
Huffer

 

Necropost...

I just have to say that the boot puller and the universal spark plug socket are worth the money.

 

I would ues the motor craft plugs and wires , common misconception is that autolite is not! a replacement for motor craft,if not using the motor craft plugs try the double platinum or the irridum plugs in ngk.

 

Dude, If I were you, I would do my homework before saying something stupid like that. The Motorcraft plugs used in the Rangers and Explorers are made by Autolite. If you don't believe me, hold the Autolite and Motorcraft plugs side by side. They are identical in all respects other than the color of the ink used to stamp the numbers, and the numbers themselves.

Now I would say that some people a misconception that Autolite is a Motorcraft or Ford company, and this is not the case. Autolite is a Honeywell brand.

I have never heard of anyone using anything other than Autolite/Motorcraft with any degree or repeatable success in these engines. NGK makes a great plug, but the heat range is wrong. This can cause pinging in extreme cases, and results in consistently elevated plug tip temperatures the rest of the time. This directly equates to accelerated wear on the plugs, and it also stresses the rest of the ignition system.

 

Yes i will agree with you that the motor craft plugs are made by autolite but thay are also made to motorcraft specs , rather than autolites specs makes a big diffrence especially with the 4.0 engines , found that the hard way myself

 

LOL, If you found that the hard way, it is because you did not use the OE spec Autolite plugs. Autolite makes a lot of plugs, and you have to get the ones with the right gap, heat range, and platinum configuration.