2007 Ford Explorer 4.6l 3v Missing/Bad Coils

[rowekmr]

I just got a 07 Explorer Ltd with the 4.6l 3v engine that sounded like a lawn mover when running. The CEL light on with codes P0171 Bank 1 system lean,P0300 random misfire,P0304 Cyl 4 misfire, P0305 Cyl 5 misfire, P0355 Ign coil 5 malfunction.

I have owned a few Fords with mod engines and know the coils go out with time but in the past I had the stealership do them but this time I decided to try to tackle it myself. I got 2 motorcraft DG511 coils and replaced the #4 coil but when I got to #5 it was disconnected from the engine harness and the coil was pulled up out of the hole partially. I replaced that coil also and when I started it the idle was still bad at first but it slowly cleared itself and eventually idled smoothly.

I drove it for 20 miles mainly city driving with no issues but noticed on highway when cruising that the engine missed when I gave it a little gas to accelerate. After that driving it there was no codes so my question is do I need to change another coil? If so how do I now try to find out which coil is bad?

I saw on YouTube that many people put dielectric grease in the end of the coil boot but I couldn't find any at home when I did this. Could that be the problem, should I buy some and use it on the 2 I installed?

Also when I installed the coils they did not sit all the way down on the plug I had to tighten the hold down screw to get them to seat completely, is that normal?

[MegaCab_PL]

rowekmr -

I have an 06 with 263 k miles (owned it for almost 11 years by now), and it's one of the better cars I have had. Yes, I have my hands in it often but parts are cheap and you can get stuff from any junkyard if needed. I went thru the spark plug nightmare at 100 k and after that I turn them loose once a year without replacing them unless needed. Use Motorcraft parts only for the ignition and you'll be fine.

Visit this site, lots of good info:

http://www.explorerforum.com/forums/index.php?forums/stock-2006-2010-explorers.111/

[rowekmr]

Now I got a P0420 low catalytic efficiency code for bank one. Interesting thing through all the driving with misfires I didn't get that code until all plugs were changed.

[rowekmr]

All plugs are now changed and no misfires at all. I don't know if any broke on him but I am glad that part is over now I have to tackle the other common problem exhaust leak from manifolds. When it first starts up it clackity clack like its in bad shape but after 20 sec the gap closes and the engine is quiet again.

[colliehauler]

Most of the time you can get by changing only the coil boots, (they sell coil boot sets).

Just had my coils and plugs changed in my 5.4. Another tip the mechanic gave me was prior to changing run a can of Seafoam through it to help git rid of carbon around the plug for easier extraction. This also helped clean the fuel injectors as well.

[mosseater]

OP. the plugs were the cause of my misfires. I changed them all the gap was very wide. Broke 4 and the other 4 came out, but you're right, the Lisle tool seems to be the better tool. Hit me off line if you have any questions about doing them.

[rowekmr]

Well I wasn’t going to do the exhaust gasket/manifold repair and these plugs break 3 different ways with the one I did the easiest so I decided to leave the rest to the pros this time.

I started small because the OEM coils are $70 and plugs $17 (my cost). I was trying the minimal approach lol

This isn’t my DD so wasting time didn’t inconvenience me. I learned a lot more about these engines.

[Derick]

I gotta say, with all this back and forth...you should have just bought 8 new plugs, and 8 new coils. When I had my crown vic, the 4.6 was so stupid easy to work on, it just made sense. I kept a few of the old coils, but got new AC delcos for like 150 bucks for all 8. Wasting the time, back and forth, just wasnt worth it for 200 bucks in parts to know you've got ALL new stuff under the hood.

[rowekmr]

I was looking at high powered electric cordless impact wrenches last night to attempt to remove the remaining plugs with but changed my mind because I also need the exhaust gasket replaced.
So as suggested earlier I dropped it off at the dealership lol

[dodge_guy]

Yes, do the plugs. And a small impact and a warm engine works perfect. It breaks up the carbon that builds up around the tip. When cold the carbon acts like cement. And got it gets sticky! That’s why warm is perfect.

[rowekmr]

UPDATE
Drove the truck a little more and the CEL light came back on and the code was for a misfire in cyl#5. I removed that new coil and discovered that spark plug was already loose and when removed the tip stayed in the head. This must be why previous owner got rid of it (I got from donated auction).

I bought the Lisle spark plug removal tool from NAPA after watching YouTube videos on it. It was fairly straight forward and tip came out after 2nd try. I replaced that with new OEM plug with anti seize on barrel of plug and threads. Reset CEL light and went driving again much smoother but still a miss with code for misfire in cyl #3. Pulled that coil and saw a pile of dirt in plug hole. Blew sediment out after spraying carb cleaner using air. Reconnected everything and took truck out for drive and still a miss now code for cyl #1. It was getting dark so removed that coil and saw some sediment in the plug hole and cleaned it out. Reused that coil and buttoned it all up and after the normal trip no codes were triggered but still a very slight miss but much less than before.

I'm going to drive it some more to see if the computer can point me at the right cylinder otherwise I might try to replace the other plugs only if I can use a smaller impact to remove the plugs from a warm engine. Many say that's better than Fords process of using ratchet wrench going back and forth 1/4 turn at a time on cold engine after spraying penetrate/cleaner down spark plug hole.

[rowekmr]

Where's your sense of adventure 😉

Yeah I know about the cam phaser issues but one problem at a time lol

dodge guy wrote:

rowekmr wrote:
I do know that the spark plugs can break when trying to remove them which is why I didn't touch the spark plugs.

Get into...do you mean getting the truck or trying to replace the plugs? If things get over my head it will go to Ford I was just trying some DIY'ing.

dodge guy wrote:
You changed the coils but not the plugs?

You may want to search the internet for 3 valve triton spark plug issues. then sit back and ponder your what you got yourself into!

Best to take it to the dealer and let them do it. and yes it will be expensive, but better than you having to deal with it!

Ok, gotcha. Then you did good. Now it’s time to get into the plugs!

And yes got into meant buying a triton 3valve. And to make matters worse look into can phaser/timing chain issues!

[dodge_guy]

rowekmr wrote:
I do know that the spark plugs can break when trying to remove them which is why I didn't touch the spark plugs.

Get into...do you mean getting the truck or trying to replace the plugs? If things get over my head it will go to Ford I was just trying some DIY'ing.

dodge guy wrote:
You changed the coils but not the plugs?

You may want to search the internet for 3 valve triton spark plug issues. then sit back and ponder your what you got yourself into!

Best to take it to the dealer and let them do it. and yes it will be expensive, but better than you having to deal with it!

Ok, gotcha. Then you did good. Now it’s time to get into the plugs!

And yes got into meant buying a triton 3valve. And to make matters worse look into can phaser/timing chain issues!

[Fordlover]

I did all 8 coils and new plugs at 105K miles on my 2v 4.6 V8. I didn't have any issues before hand, but I know the coils tend to die a slow death, and it was easier for me to replace them all at that time since I had them out, and for the 200 ish bucks it was worth it to me.

Hard to tell if your issue is plug/coil related, or something else.

FWIW, independent shops that do lots of business have gotten very efficient at doing the plugs on 3v mod engines.

[rowekmr]

Double Post