Time to replace all coils?

[brucemc777]

Bought a used 06 Liberty for one of my daughters several months ago. Started to have some (more) problems yesterday, this time running poor. MIL, code P0303. Pulled the #3 plug, definitely overdue for replacement, but can't really see that the sole cause for the issue. Pulled the spring out from the coil, extended it, got it to stay back in there. Vehicle running fine for now.

The spring (that provides contact to the top of the plug) showed about as much aging as the plug. My thoughts are that like the plugs, if one is going, i should just replace them all; seems Rock has ones that look decent for a little under $15/piece. Am i burning money or am i on the right track?

Much appreciate all of your knowledge and experience!!!

 

[uss2defiant]

spark plugs and ignition coils would be good.

 

[LONGJEEPOWNER]

I replaced my spark plugs, coils and wires at 130,000 miles. Always ran great but I felt it was time anyway!

 

[LibertyTC]

Yes the Jeep will run better with new plugs.

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Use the copper core ngk's as above.

The coil packs fire those spark plugs hot.
Mopar coil packs are best.
I got away using the Standard Brand #UF270 with good success.

 

[brucemc777]

Many thanks, everyone!!!

Glad to see this is an active board; with four daughters driving and nothing but older cars in the family, i depend on the help of good folks to keep us running.

 

[tommudd]

Yes stay with copper core NGKs and the best coils if not Mopar that you can get, those cheap ones are good if you just want to buy them and throw them away as soon as they arrive

 

[brucemc777]

Ewwwwww boy. Well, the price of the plugs just went down by a few bucks each as i was going for the iridium or double platinum, but the price of coils just went from about $15 to about $35! Let's see... six times...

Y'all saved me from buying trash and completely wasting money; thank-you! (even though it kind of stings for now)

 

[uss2defiant]

autozone has 6x for 128 for lifetime warranty.
don't flak me for bringing AZ up. YMMV

I haven't had any issues with my 3x duralast coils.
And I'm ok with the fact that if I had any issues, it'll just be a simple exchange at the store versus having to deal with online retailers.

 

[tommudd]

Ewwwwww boy. Well, the price of the plugs just went down by a few bucks each as i was going for the iridium or double platinum, but the price of coils just went from about $15 to about $35! Let's see... six times...

Y'all saved me from buying trash and completely wasting money; thank-you! (even though it kind of stings for now)

Yes never go with plats or iridiums unless you want a poor running KJ
They do not like them at all
NGK coppers and change every 30,000 miles or so

 

[Mator1988]

autozone has 6x for 128 for lifetime warranty.
don't flak me for bringing AZ up. YMMV

I haven't had any issues with my 3x duralast coils.
And I'm ok with the fact that if I had any issues, it'll just be a simple exchange at the store versus having to deal with online retailers.

I order that set and next day got an email about how they couldn't fill my order due to unable to receive them from factory

 

[uss2defiant]

wow. did you order shipped to you or to the store?
i think for that price you'd get free shipping to yoru home.
Dont' forget to add any coupons too.

 

[brucemc777]

Like to learn something additional here please! - why copper plugs instead of iridium or titanium?

 

[tommudd]

Like to learn something additional here please! - why copper plugs instead of iridium or titanium?

Your ignition system is set up with the resistance of copper core plugs built in,change that resistance(platinum plugs) and you throw the PCM in a loop and it tries to compensate which always ends up in either misfires,burnt coils,bad mpg's,generally running very rough, and extremely shortened plug life(seen platinums in Jeeps totally fried with only 10k miles on them). When I bought the 03 it had a slight miss at full throttle, drove it home, pulled a plug and had plats in it, one of my points in getting the price lowered was that
10 minutes after being home ran like a champ with new copper core NGKs

 

[brucemc777]

For my other cars, how do i find out if they are calibrated for a specific plug? (Wow. I feel like i am asking "Where does the oil go?...)

 

[LibertyTC]

The best method for determining actual OEM spark plugs for a certain vehicle will be found in the owners manual of any vehicle.
Alternatively there may be a tune up decal under the hood mentioning the recommended spark plug type & gap.
This is what our KJ decal looks like.

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[brucemc777]

Thank-you! I never knew this could be an issue-

 

[Squamish_Steffen]

What is the deal with the gaps here:

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[tommudd]

What is the deal with the gaps here:

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look at nothing but the right plugs, NGK ,

 

[tommudd]

Thank-you! I never knew this could be an issue-

Manufactures spends millions on just plug testing to see what works what doesn't
Buddy of mine in Toledo ( Ohio ) did just that for 30 some years, last 15 was for boats
Champion has a large private lake in Florida that he worked at for testing boat motors

 

[Squamish_Steffen]

Was just wondering why the NGK copper plugs with code ZFR6F-11G lists the cap at 0.044 instead of 0.040...
And none of the other plugs list 0.040 either.
Guess I'll order the NGK ones and hope they are correct...