Changing Spark Plugs on 91-94 Explorer

[catfisher81]

Cool

Awsome write up, This actually helped me. I have been wanting to to a complete tune up on my ex. but i was wanted some one to post about the spark plugs. but yeah thanks and good job once again.

Christopher Adams
_______________________________________________
1991 Explorer 5 speed, 4.0, K & N, 108,394. All Stock!!!

 

[Zolepup]

Thanks everyone for the good comments and labeled pictures--big help to this desk jockey. I changed my '92 plugs last weekend. First time since installed Ford rebuilt engine 90K ago. I am not a 15 minute guy, but reading the post gave me the confidence to know I was going about it the right way. I got to the rear passenger plug without jacking---just turned the wheel all the way to the left--good tip. The middle plug wire on the passenger side would not come loose--I finally pulled the rubber boot apart and used a carpet knife to slice it against the side of the plug and with a plumber's plier and determination I got the rest of the boot off. (I had new wires anyway---with no car payment on a 92 why not do it right?). I didn't have a plug wire puller--not sure if that would have helped--will probably get one for next plug project (02 XLT Explorer). Badge of Honor: my gashed knuckle from the driver's side bank should be healed by end of this week! Runs better, I have pride ownership and satisfaction of not having paid the shop.

 

[Zolepup]

Thanks everyone for the good comments and labeled pictures--big help to this desk jockey. I changed my '92 plugs last weekend. First time since installed Ford rebuilt engine 90K ago. I am not a 15 minute guy, but reading the post gave me the confidence to know I was going about it the right way. I got to the rear passenger plug without jacking---just turned the wheel all the way to the left--good tip. The middle plug wire on the passenger side would not come loose--I finally pulled the rubber boot apart and used a carpet knife to slice it against the side of the plug and with a plumber's plier and determination I got the rest of the boot off. (I had new wires anyway---with no car payment on a 92 why not do it right?). I didn't have a plug wire puller--not sure if that would have helped--will probably get one for next plug project (02 XLT Explorer). Badge of Honor: my gashed knuckle from the driver's side bank should be healed by end of this week! Runs better, I have pride of ownership and satisfaction of not having paid the shop.

 

[BWTGUY]

If you don't have an air compressor to blow out debris from your spark plug cavity, and you want to make sure that nothing falls into the engine when you pull the plugs (Sand in a cylinder is a very bad idea) a can of compressed air/nitrogen from an electronics/computer store will do the job. It wont cost much and is cheap insurance where you need compressed air.

 

[Shinryu]

thanks i think i will do mine now.

 

[Java Navajo]

Thanks, this is a good write up. Alot of good tips in the thread too. I did mine yesterday and it went well thanks to all of you. Three quick notes though (maybe not on everyones Ex' but in my case...).

First, the Bosch wireset comes pre-greased, I got the dielectric grease for no reason (I used a little extra on the boots since I bought some, the factory set was practicaly superglued on).
Second, the Bosch wires are all a little longer than their factory counterparts, pick the shortest new wire to replace shortest old wire, then next shortest etc., if you go by exact length you will be SOL when you get to the last wire.
And finaly, the wires go on the coil 1,2,3 on the left and 4,6,5 on the right (respective to their cylinders) not sure why one side is in order and the other isn't.

BTW I didn't jack it up, use a wobble extension/magnet socket or take off the wheel well liner, just turned the wheels all the way left and busted up my knuckles getting to that back passenger side plug.

 

[mehedgec]

I was able to get them all from the top when I did mine. I'm gonna be doing them again soon, so hopefully the anti-seaze I used helps this time. I needed the hand of god to break them loose last time.

I currently have motorcraft coppers in there, Should I upgrade to platinums? What brand does everyone get the best results with?

 

[Willard]

Coppers are fine, they just aren't going to last nearly as long as platinums. The only advantage the platinums have is their longevity, everything else is similar to copper plugs.

Motorcraft is always a good choice, or Autolite which is who makes the motorcraft plugs anyways.

 

[huntman58]

I always use anti seize on my plugs and I also found that on my 1st gen x that if you remove the air tube and top of the stock air box if you still have it getting to the two front plugs on the passenger side is cake then as has been said go threw the opening on the wheel well liner for the one next to the fire wall.

I have got it down it a cake walk any more and even got the kids doing them for me now as a learning tool to show them that some times thinking it threw first is better then just attacking it. A neat trick is also to use a straight sparkplug boot and wire cut down to start your plugs as the wire will give way before you can crass thread any plug.

The only time I have removed the inner wheel well liner is to do a compression test as I needed that extra clearance then. Next time I do them or a compression test maybe I will take pictures and do a write up showing how easy a plug change can be or a compression test

 

[coolerpooler]

Some good spark plugs to use

In my '94 may it rest in pieces i found the best way to get the best use out of spark plugs, coil, and wires was:

Plugs- E3 Diamond fire for some reason only Pep boys sell them they come pre-gaped and from its design the gap will not be wrong (no need for gaper tool). They were the best i ever used!

Wires- I got some 9mm wires off of summit they were made by JBA headers worked fenominal especially with the E3's

Coil- Got an ACCEL super coil with all these put together my gas mileage went through the roof and a good increase in power!!!!!

 

[Roadrunner777]

This is a good thread to keep near the top, and I will add my try at this a few days ago.

The idea began when I decided I would clean out the heater blower box, which required me to remove the air cleaner and box. When I did that, I suddenly was able to at least see all the passenger side plugs. I pulled an easier plug from the driver side to sample and it was, like everyone else, ashy and about twice the normal gap. They were motorcraft standard plugs, and at 80k miles, they may have been original.

Anyway, I replaced with the Autolite equivalent, Autolite 765. And, on the plugs, they are a bit odd because they have a low shoulder or I guess called half thread. I think it is a profile they built into the hole so you don't have to turn the plug 30 times to get it out. Nice. So, if they look weird, it's ok, it's good! New wires too.

I had the airbox out, so the front passenger (1 and 2) were just as easy as the others. I opted to jack up and remove the tire for the back plug, mainly because I don't have any history with this truck and I wanted to inspect the brakes and hub anyway. (Brakes and shocks coming soon)

Things that helped to have:

I grabbed all my extensions, wobblers, and universals. I used them all at one point or another. At times, I had 2 feet of extension built up to reach for convenience.

I did spend some time on my spark plug socket so it would not grab too tight on the plug. If you end up leaving the socket on a plug, it could get interesting.

I have about 30 years on engine work. This rates as about medium on the spark plug scale.

 

[jet64155]

tune up

Lots of great info here. I am planning on changing the plugs on my 92 sport this weekend. That passenger side plug by the firewall had me pretty spooked. Now I'm not so nervous. Thanks to everyone for sharing and thanks to Mr Q for taking the time to document the process.

 

[Roadrunner777]

It's easy... choose your method, I did the tire removal and I was staring right at the plug.

 

[IronCamel]

Don't let it sound intimidating, it's not. I change that back plug with a ratchet and a 5/8 plug socket. I just reach in from the top and put the socket on it, then reach in with the ratchet and connect it. Loosen it enough that you can unscrew it with your fingers, and reverse the process to put the new one in. Takes me less time than jacking it up or removing the wheel liner.

Just pick the method that appeals to you most and do it. As long as you don't force anything along the way you'll be perfectly fine.

 

[mr cribb]

My hint would be remove airbox assembly for better angles on front two passenger plugs.

I just moved the RF flap to the side with what seemed like 10 feet of extentions and got the rear most plug out.

 

[mhamill]

Rear Passenger Spark Plug change hint

I was rather dreading this but....it went quite easily. The trick on the rear passenger plug was to simply go in through the wheel well slot after removing the tire with a 3/8 inch socket with a 15" extension and universal joint and a long but shorter socket which was 2 1/2" long. This longer but shorter socket allows the socket to clear the air conditioning unit and still accomodate the porcelain of the spark plug. It was the easiest to remove of any on the passenger side in fact. Removing the other two from the top side I only removed the breather tube from oil fill and used a 1/2" socket with about 16 " extension and universal joint because it is a bit sturdier. So much for procrastination. I put it off far too long and for nothing. MarkH

 

[yragsapo]

How much torque specifically should be used on the spark plugs?

15 ft/lbs

I have a '94 Explorer Sport. I tried changing my plus this past weekend, but had not seen this thread until today. After doing the "easy 5", I started the engine and took the truck to pick up my boy from a couple of miles away and my truck was backfiring like crazy whenever I gave more than light acceleration. I had gapped the Bosch Platinum Plus (4005) plugs to .54. The wires were on the right plug (I do my plugs one at a time after a wiring incident about 9-10 years ago). I ultimately put the last set back, after re-gapping them and changed the wires to Autolite Professionals and it got rid of the RF interference and the truck runs great. My question is, what is it with the Bosch Platinum Plus (4005) plugs that they didn't work with my truck? Since the last set were Autolite Single Platinum Spark Plug, Part No. AP605 , I guess I'll go with those again, if not the Motorcrafts.
What does everyone think of the Motorcraft Motorcraft Original Equipment Finewire Single Platinum Spark Plug, Part No. SP486? Any compatibility issues?

 

[mr cribb]

What does everyone think of the Motorcraft Motorcraft Original Equipment Finewire Single Platinum Spark Plug, Part No. SP486? Any compatibility issues?

No issues with compatibility... that's what I'm running in my truck, along with a set of new motorcraft wires 13k mi on the tune up and counting.

 

[yragsapo]

No issues with compatibility... that's what I'm running in my truck, along with a set of new motorcraft wires 13k mi on the tune up and counting.

Let me ask this, then. Advanceautoparts website indicated that these plugs should be gapped to .54. However, they all came pre-gapped to .4x (I don't recall the exact measurement, but it was consistent). Did I make a mistake re-gapping these to .54, or should I have kept them at the factory setting? The Amazon.com listing for those plugs indicate that "Factory-set gap ¿ once the proper gap is set, there's no need to re-gap". However, the one person who reviewed them said that they were not gapped to factory spec, but he put them in as-is and they worked fine.

I do have one other question. Autolite Single Platinum plugs, AP105 and AP605 are both shown as compatible with my '94 Ex Sport. The 105 is Heat Range E15 and the 605 is E14. Which one should I use, if I were going to use this brand/type of plug?

 

[mr cribb]

Let me ask this, then. Advanceautoparts website indicated that these plugs should be gapped to .54. However, they all came pre-gapped to .4x (I don't recall the exact measurement, but it was consistent). Did I make a mistake re-gapping these to .54, or should I have kept them at the factory setting? The Amazon.com listing for those plugs indicate that "Factory-set gap ¿ once the proper gap is set, there's no need to re-gap". However, the one person who reviewed them said that they were not gapped to factory spec, but he put them in as-is and they worked fine.

I do have one other question. Autolite Single Platinum plugs, AP105 and AP605 are both shown as compatible with my '94 Ex Sport. The 105 is Heat Range E15 and the 605 is E14. Which one should I use, if I were going to use this brand/type of plug?

I gapped my plugs at whatever the hood label said.... I wanna say it was in the 40thousandths range. I'm not sure I put my plugs in almost a year ago.