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How To: Spark Plug Change

50K views 32 replies 21 participants last post by  MarcD 
#1 · (Edited)
I aplogize in advance that this is aimed at the not very mechanical crowd so that they might save a few dollars and appreciate thier ride even more.

Takes about an hour or more - Thanks for the heads up EburgJeep forgot who i was writing for! Edited by albertschmitz

Tools Needed:
Anti Sieze Compound
Good Plug Gapping Tool
Pliers - You never know
Straight Pick - helps with plug connections
1/4 Drive Ratchet with 3 " extension and Deep #10 socket
#10 ratcheting Combination wrench
3/8 Drive ratchet with 6" extension and 5/8 spark plug socket - does not need to be a swivel socket
5/16 nutdriver - for the 3 clamps - intake hose and behind the airbox attached to the throttle body.

View from the front - I always start on the Passenger side - usually toughest and takes the longest. Makes you appreciate the drivers side



Loosen clamp closest to the main airbox



And then by the air filter box



Remove hose



Locate and unclip the plug for the IAT on the main airbox passenger side





Remove bolt from the passenger side main airbox



1/4 drive with the #10 socket


And then the Drivers Side



same 1/4 drive and #10

 
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#2 ·
And the clamp behind the main airbox attached to the throttle body





Now lift the front of the main airbox a bit and pull forward, if it has not been off before it will be a little tight.



You will now see the 6 or 8 coil on plug modules that need to be removed for access to the plugs - Blow them and the surrounding area off with compressed air so as not to get any debris in the cylinders when the plugs are removed.

Installed



Lifted out



They will lift up - a little effort here but no tools other than hands, try to come up straight. The passenger side rear one will require that you ease the transmission tube towards the passenger fender a bit for clearance. There is a bracket that holds a connector back there that will need to be reinstalled after the plug is finished.

Here is the connector and bracket area



The red tab will need to be slid over a small ways so that the connector can be unlatched - it is a vibration lock and you will need to make sure that you push it back when you reconnect it.



Get your plugs out and verify the gap (.044 on the 06 4.7 Liter Commander) Better to do all at once and put the protectors back on than try to remember as you are going.





Be gentle on the gaps remember they are moving in thousandths of an inch not inches.
 
#3 ·
As for removing the old plugs they will be in there snugly so you will need to use some force to remove them, if it seems excessive make sure that you are lefty lucying not righty tighening them!!!!!!!!!!!

Place the used plugs in a scrap piece of cardboard so that you can have a mechanic look them over to see if there are any problem areas. You want them in the same location that they came out of the engine so if there is a problem the mechanic will know what cylinder/bank to look at.

Use a box bottom 8" by 10" will suffice, to make an area for the plugs take a box cutter and slice an X for each plug and put the top in first so the electrode is facing up. Make sure you mark passenger and drivers side.

I just put the thread protectors from the new plug to the used one as they come out and mark the gap and location.

Example of a typical original plug at 91000 miles of use and normal wear.




The old ones like mine all read in the .054 to .060 range and that is normal, not good for fuel economy but normal wear and nothing to worry about.

Remove and replace the plugs one cylinder at a time and put a small amount of antisieze compound on the threads before install.

The plugs need to be tight but not cranked in place.

If you are a big person do not crank them down you will not like the bill that you will receive for the helicoil repair on the head.



Good luck and I hope that this saves you a few dollars for a necessity like, I dunno mods? accessories and you know the basics.
 
#5 ·
I will make this a sticky. Nice write up.
 
#7 · (Edited)
Yes bone stock factory Champions in there, they will go 100,000, but the fuel economy really starts to suck in town. The coil packs can fire with enough power for larger gaps, but I would recommend highly against that. Plugs only cost 1.75 to 5.00 depending on the brand and cores. I use Denso or NGK because I have always had great luck with them in all of my cars, trucks and bikes.
 
#8 ·
If I can make one suggestion. I saw this in another thread and I did it and was glad I did. Which is to use a compressor to blow out all the dust a debris before removing the plug its self. I did it and man the stuff that came flying out of there that could of possibly slipped in while changing the plugs just suggestion. Awesome post by the way.
 
#12 ·
Spark plugs for 4.7 engine

I own a 2008 commander with a 4.7 engine double plug.
Reading the owners manual said that one set of spark plug it needs to be changed at every 30,000 miles and another set at 100,000 miles. If this statement is correct, which plugs are the one that needs to be changed every 30,000 miles?
 
#13 ·
I own a 2008 commander with a 4.7 engine double plug.
Reading the owners manual said that one set of spark plug it needs to be changed at every 30,000 miles and another set at 100,000 miles. If this statement is correct, which plugs are the one that needs to be changed every 30,000 miles?
The upper plugs, the ones on the intake side every 30 k
Or, If you want, put the same plugs that are on the sides (the 100k ones) up top.
I believe they are just the double platinum version of the top plug number.
Then you leave those in till 130k.

Rob
 
#14 ·
Nice tutorial!!! I have one suggestion. I was just doing this when my plug socket came off the extension. Thanks be to all that it was one of the front instead of the back 2. I had to fish it out with needle nose pliers. I taped the socket to the extension for the remainder!! As well, make sure the rubber is still inside your socket when installing.

HTH! :)
 
#15 · (Edited)
You can put the extension back in the socket, then turn the socket backwards to unwedge it from the spark plug. Doesn't always work, but sometimes it does, its worth the 10 seconds to try since it takes less time then finding your needle nose pliers, if the rubber insert is still enough keep the socket stuck on the spark plug, you're no worse off.

Also, look inside your socket and look for the little divot in 3/8" drive fitting, line that up with the ball detent on the extension, the detent will fit in the divot and give greater resistance to pulling out.
 
#18 ·
having a misfire problem in cylinder 3 ...which one is cylinder three and what would be the proper thing to do (4.7L V8)...trying to save a few pennies
 
#19 ·
I tried finding out where cylinder 3 was but couldnt find anything online. But to fix the problem you might just have a bad spark plug. Once you figure out where that cylinder is pull the plug and see how bad it is.
 
#22 · (Edited)
Number 3 is the second one from the front on the driver's side. This was my #3 plug. Note the burn mark on the insulator and the corrosion on the metal. The dealer tech said I needed a new coil ($40). I put dielectric gel in the boot and put it back together; with a new plug. I'll check it later, but the gel should do the trick. I always use it on conventional type plug cables, so it should be good here also.

I also have an oiled dirt seal on my #4 coil that you have to buy a new coil to get, so I put it back together and pushed it down into place with a screw driver. There is an O-ring below it that prevents the oil from getting down to the plug, so there wasn't any oil on the spark plug. I think it got oiled by someone being sloppy checking the oil, since the dipstick comes out right above it.

BTW, this was on a 3.7 rather than a 4.7 engine. I got into the wrong thread.

Richard
Commerce City, CO

'07 Commander 3.7
 

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#20 ·
If you are referring to a code, GetNby, it means third cylinder of the firing order, not cylinder number three.
The firing order is 18436572........third cylinder in firing order is number 4.
Cylinder numbering on Mopar V-8's is, Odd #s on left, Even #s on right......left and right of a vehicle are determined as, sitting in it, looking forward.

So, 1357 are on left, 2468 on right.
Your code indicates the second cylinder from the front on the right(#4) side is experiencing a occasional misfire......if it was a steady misfire, the Check engine light would be flashing.
Occasional misfire can be caused by a partially obstructed fuel injector, a weak ignition coil, or a bad plug related to that cylinder.

Clear the code and transfer the coil to a different cylinder, and reinstall the removed coil to the cylinder setting the code and go for a drive.
If the same code resets, you now know to next change the plug in the third cylinder or #4.
If a code sets for the cylinder you moved the suspect coil to, replace that coil.

Once the plug is changed, again, clear the code and road test......same code, there most likely is a injector problem at that cylinder.

If this proceedure points to a injector concern, run a large bottle of Chevron Injector Cleaner through with a full tank of a name branded fuel.
I recommend the Chevron product only because it contains Techron, a licensed detergent only available by them and the only detergent all automakers have given their recommendation to.

Rob
 
#21 · (Edited)
Albertschmitz, I have a question...you said earlier, "Get your plugs out and verify the gap (.044 on the 06 4.7 Liter Commander) Better to do all at once and put the protectors back on than try to remember as you are going." I lchecked the sticker under my hood and it read plain as day tto gap the plugs at .040 on my truck (aslo an 06 4.7) Where did you see that yours was to be gapped at .044? Anyone else notice a discrepancy? Also, for those of you that went with Champion iridiums...the website says they come from the factory with a gap of .044....but that isn't what my truck's sticker under the hood says to gap mine at. Should I attempt to gap the iridiums for max function/mpg, etc.? Or just go with the easier-to-gap w/o breaking the tips double platinums? My mpg went from 21 on the road to 14 in the past YEAR ALONE with no changes to my truck's setup. Only thing I can think of would be the plugs. My driving is nothing but stop n go...2-3 mile trips throughout the day and my Champion coppers are at close to 30K old. I imagine with the type of driving I do they are done for.
 
#23 ·
Great write up - thanks.

So, after reading this last week I went out and bought the things I needed to change my sparks on my 2007 HK at 56k miles. The plugs were last changed at the 30k service and I was interested in seeing what condition they were in.

My tips for the job on the HK...

1. You need to remove the bulkhead seal otherwise you cannot get the air box back on the throttle intake correctly. It comes off ok but... (took me 10 minutes to work this out!)

2. The air box fasteners on the HK are not 10mm as per the pictures but star connectors (not sure what they are called!).

3. I agree that you need to blow the spark plug sockets out with compressed air before taking the plugs out - mine had everything but a family of mice living inside!

For the record, my old sparks (NGK V-Power) were all around 0.050-52 after around 26k miles. New NGK V-Power plugs were set to 0.044 after I found them to be around 0.040 from the box (even thought they were supposed to be factory set at 44).

The job took around 1.5 hours and left me with a great feeling, having not changed a spark plug for getting on 20 years!

The tutorial was just what I needed to get stuck in with confidence - thanks so much.

Andy
 
#24 ·
I just did the plugs on my 2007 4.7L flex fuel engine and can confirm the gap was listed as 0.040. I will also confirm that the back plug on each side are a PITA. Passenger side coil pack was obstructed by the trans dip stick tube and the engine dipstick tube. I had to push on them to get the coil pack up and out of the engine bay.

I am fairly certain my plugs were original at 68,000 miles but I was surpised at how well it ran around town and on the highway.

I had to tape my socket on to the extension as well mainly because the foam boot in the socket was fairly stiff
 
#26 ·
Are you guys changing spark Plug Wires at all during this process? This is on my "to-do" list now that the Jeep 4.7 2007 Flexfuel is hitting 100k miles.

Is my jeep single or double plug? I am still trying to figure out these "HK" and other 2 letter terms and what they mean...
 
#27 ·
#31 · (Edited)
Got it done....all in all took about 2 hours.

Well I can say that I spent more time fishing out my spark plug socket than actually changing the plugs! It wasn't bad at all, and I didn't even unplug the wire back on the passenger side, but worked around it.

Took time to install some new fog lamps and completely detail the engine while I was at it.

The average gap was anywhere from .060 to .074 on the plugs I removed. After I fired it all back up when I was done, I could tell the idle was instantly smoother, and the power and pickup was a bit better.

Interested to see what the first tankful will result in MPG.
 

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#32 ·
Anyone know how to replace the lower bank sparks plugs on a 08 Flex? And any pictures? Thanks in advance. Steve
 
#33 ·
PITA!!!

I haven't replaced my lower set in my 4.7 yet, but I did remove #2 to check to see if they had been replaced at the recommended interval and they had been. :) To answer your question, remove everything out the way like you was going to pull the valve/head covers. I'm not saying to pull the valve covers, but you would be able to see/access all the plugs easier if you did. If you did pull the valve covers, you could replace all your "lifters" too if any of the rockers are tapping.

Here's how I would do it, since I just replaced all my lifters (no more tapping).:
Tools: (3/8" drive)
Sparkplug socket with U-joint (recommended, but can be done with a regular socket)
At least TWO U-joints
Multiple extensions (At least TWO, 8" extensions)
Dielectric grease
Lots of patients

Remove airbox
Drivers side:
Disconnect the battery
unplug/unhook as much of the main harness to gain access to the plugs.
move main harness towards the engine
unplug EVAP thingy (has two hoses) and move it to the towards the engine, might have to tie it out the way
Be gentle pulling on the plug boots. the clearance is tight and a torn boot could have one swearing like a sailor ;)

Passanger side:
Remove airfilter box top and filter
Remove Serpentine belt
Unhook coolant overflow bottle and place on the radiator shroud
Unbolt/Unplug A/C compressor and gently place it in the air filter box, this will move the A/C line enough to access the passenger side plugs. If one has the rear climate control, the A/C line will only move a little, but enough.
There should be enough room to remove the plugs now.

Everything goes back in reverse order.

I've probably forgotten something, but its not as hard as it may look..
 
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