Hi All,

I've got a '93 F150 with the 4.9L. I wanna replace the plugs, but I took a look under the hood last night and it seemed like quite a task to gain access to some of them. Any advice on doing this?? Should I use a certain socket extension? Should I remove anything to make them more accessible?

Kind of a stupid topic, but I figured I should check in with you guys before I make a fool of myself...

Thanks in advance!

 

i did it for the first time a while back on my 7.5. it wasn't bad. what took the longest was having to be high off the ground and reach low into the engine. i had a little 3" extension and a cheapo set and got it done. a longer extension, an actual spark plug socket, and one of the flexi-headed elbow deals would have helped.

 

quick tip on installing new plugs, use a piece of hose that fits snuggly on the plug but allows it to spin with some resistance. The hose is flexable enough to get around things. This also helps with crossthreading issues. When the plug is seated just twist the hose off, tightening may require other tools but it makes it alot easier to get them started.

 

The elbow definitely does help and was a must for a couple of mine on my truck. I also noticed that it's actually easier to get the plug closest to the firewall on the passenger side from underneath. At least on my truck. I'm not sure if my headers make any difference.

 

put a blanket over the fender, use a sturdy, level whatever to stand on, use anti sieze, use die-electric grease, use the proper sockets and extensions, try not to hurt any vacuum lines, do one plug at a time, pay attention to wire routing, do not over tighten plug, do not leave them loose, use motorcraft regular plugs, get new motorcraft wires if you need them,.

hope that helps.

guess who just had an expresso.

 

It is okay to ask for advice for this engine, but stay away from the guys that change the plugs in their Triton V-10's. There will be NO sympathy from them.

 

WHO MENTIONED TRITON V10S.......................... lol mine were a BITCH but you shouldnt have all those cop problems

 

My 4.9 is a real joy to work on. Everything is so much more accessible than many cars I have owned. Thinking of a 340 Plymouth Duster, and a 440 Plymouth GTX.
The only thing special needed is something to stand on. After using an upside down 5 gallon bucket that was too tall and tended to slip away at the wrong time, I ended up getting a fold up aluminum step at Harbor Freight. That little sucker is real handy for lots of things, and at about 12 inches high it is perfect for working on the engine.
I don't have to remove anything to pull the plugs. All of them are easily accessible except the one close to the firewall. It is not hard to get at, but it is not visible. Have to do that one by feel.
When I first got the truck, I found 2 plugs slightly loose. Changed them as part of the first major tune up and a few days latter noticed 3 plugs a little loose. Easy to tell if they are loose, by holding onto spark plug wire while it is running. If loose, I can feel a tapping in the wire. Had to pull all the plugs, stuck a small piece of paper towel in each plug hole, and sanded the seats in the head clean. Blew out the dirt and abrasive, then pulled the paper towels and put the plugs back in. No more loose plugs.
I use 3/8 ratchet, extensions, universal, and spark plug sockets. Seems like little easier to get them in and around things than the 1/2 inch tools. Just because I like using it, I usually slip a long extension in and use air ratchet to remove the plugs, but put them back by hand and tighten with regular ratchet.
Don't forget to set the gap. A neighbor of mine once changed his and assumed they came gapped correctly. Took a long time to figure out why it ran so bad after just being tuned up. Besides the gap being too small on some and too big on others, one had no gap because he dropped it and just stuck it in anyway.
Good luck Frank

 

thanks a bunch for the help, guys! very much appreciated!

 

A couple of other questions i forgot to ask...

1. fmr9, you mention setting the gap correctly. I'm not quite sure how to do this. Any advice?

2. Am I to assume I can use a 5/8 spark plug socket?

Thanks again in advance!! Much appreciated!

 

for gap: read the sticker on your radiator support.

for 4.9 i think it is the larger spark plug socket 13/16"

 

Easiest way is to pick up a spark plug gap gauge that looks like a 50 cent piece. All the auto parts places have them. Make sure the side electrode, lines up with the center electrode . You can use pliers to bend it slightly if needed. Gently tap the the side electrode and close the gap up until the gap is about .030 inch. Insert it into the plug gap gauge and work it around until you get the right gap. For my 90 4.9 that is .045inch. If you open it too much, just tap it shut a little and do it again.
Good luck Frank

 

I removed the air filter and those hoses that go to the throttle. Use the big spark plug socket. Make sure it's on the plug good and snug, apply a little torque to keep the socket from slipping off the plug, then put the box end of a long wrench over the end of the rathcet for leverage and twist it loose, real slow and easy. The one in the back crawl under the truck and reach in from there. The others I climbed up on the front and reached in... if you do that be careful you don't lean on the master cylinder.