Wings fan

I was very careful also but at 78K the little twist to break the seal also left the metal insert on the plug.

SwampRunner

Just a short note on the plugs, since they are part of the engine and as such a part of Drivetrain they should and do fall under warranty. Had mine check at 75,000 km's and was told there was no issue with them and if there was would have been replaced N/C under warranty. You can choose to replace on your own if you want during this period.

I get between 19 to 24 MPG and my plugs have been in the vehicle for over 103,000Km's. 87 octane used from day one. It is time for a fresh set but I am replacing the rear rotors and brakes today (originals started to chirp last week).

OH9JK

3.3 Maintenance Costs Not Covered
Your warranties don’t cover the costs of repairing
damage caused by poor or improper maintenance. Nor
do they cover damage caused by the use of contami-
nated fuels, or by the use of fuels, oils, lubricants,
cleaners or fluids other than those recommended in
your Owner’s Manual.
The warranties don’t cover the costs of your
vehicle’s normal or scheduled maintenance — the
parts and services that all vehicles routinely need.
Some of these parts and services, which your warran-
ties don’t cover, include:
• lubrication;
• engine tune-ups;
• replacing filters, coolant, spark plugs, bulbs, or
fuses (unless those costs result from a covered
repair);3.3 Maintenance Costs Not Covered
Your warranties don’t cover the costs of repairing
damage caused by poor or improper maintenance. Nor
do they cover damage caused by the use of contami-
nated fuels, or by the use of fuels, oils, lubricants,
cleaners or fluids other than those recommended in
your Owner’s Manual.
The warranties don’t cover the costs of your
vehicle’s normal or scheduled maintenance — the
parts and services that all vehicles routinely need.
Some of these parts and services, which your warran-
ties don’t cover, include:
• lubrication;
• engine tune-ups;
• replacing filters, coolant, spark plugs, bulbs, or
fuses (unless those costs result from a covered
repair);
• cleaning and polishing; and3.3 Maintenance Costs Not Covered
Your warranties don’t cover the costs of repairing
damage caused by poor or improper maintenance. Nor
do they cover damage caused by the use of contami-
nated fuels, or by the use of fuels, oils, lubricants,
cleaners or fluids other than those recommended in
your Owner’s Manual.
The warranties don’t cover the costs of your
vehicle’s normal or scheduled maintenance — the
parts and services that all vehicles routinely need.
Some of these parts and services, which your warran-
ties don’t cover, include:
• lubrication;
• engine tune-ups;
• replacing filters, coolant, spark plugs, bulbs, or
fuses (unless those costs result from a covered
repair);
• cleaning and polishing; and
• replacing worn wiper blades, worn brake pads
and linings, or clutch linings.

• replacing worn wiper blades, worn brake pads
and linings, or clutch linings.

• cleaning and polishing; and
• replacing worn wiper blades, worn brake pads
and linings, or clutch linings.

Mark Doiron

This would seem to be obvious, but what that says is that if it's a normal time replacement, it's not covered. If the part fails, it's covered. In the case described (replaced them because they were gapped 20% larger than specified), the part would not be covered by warranty. In fact, the plug could have been cleaned and regapped--there was a time before high energy ignition systems when that was standard practice. As for assuming that a 20% too large of a gap is going to cause poor performance, let me make a counter-assumption: That the engineers who designed the engine are well aware that the gap will increase, and that's why they specify the gap they did, and the time to replace the plugs that they did (99K miles, in case anyone is interested in their take on it). As for me, I have 76K miles on the same plugs. I will replace them when I install the Benchmark Designs dual-battery kit because it makes access even more difficult--or when I get to 99K miles--whichever comes first (if you've dealt with Benchmark, then you know exactly what that means).

Covert_Ops

Just did my plugs and wires today... NGK V-Power #LZTR5A-13 and Carquest wires 35-6346.

Funny thing was that they could only find about 8 sets of wires in their system. Had to have them shipped from Tennesse or something like that.

I agree on many of your points...
1 - Pulling off the wires on the driver side... Not one came of withouth breaking. Boy were they on there.

2 - Passenger side is tough with some tight spots for my big meat hooks.

I used a wire coat hanger bent straight to fish the passenger wires behind the engine. Worked really well.

Had my 10 month old supervise the job! LOL.

dmwil

Let us know how she runs on the NGK's. I've got 54k miles on mine, and it won't be long before I think about changing the plugs/wires.

toddabbott

I just did my plugs for the first time 2 weeks ago in my 08' Unlimited Saraha, an hour job - zero broken wires but I could understand the issues noted, they were tight. I used NGK iridium's- yes they are about 65.00 for the set however I'm very comfortable with them- I've run them in both my 67' mustang and 01' Lightning and never had an issue- thru track days, high octane fuel etc.. My plug change isn't going to give me a small block but faster start ups and IMO just a better/quicker overall throttle response-totally worth the coin.
Side note-The above note is correct, the drivers side is cake, passenger side is not terrible but increasingly difficult to the firewall plug which is a blind swap.

yo_marc

I changed out my plugs around....89K miles I believe.

I was able to get all plug wires off ok, and my plugs came out pretty easy. I'm lucky!

I am running NGK G-power (aka GP Platinum) plugs. Single platinum wire center electrode, and a hex-cut ground electrode. I really dig these plugs.

Of course it's hard to say what benefit I got from them, over stock, if anything. My stock plugs were pretty worn, but not terrible. I dont recall specs right now.. but I want to say they were .01" over.

The NGK's are gapped tighter. I didn't bother re-doing them. I think they are around .04", vs the stock .05".

I had a problem with detonation on longer hills or when tipping into the throttle too quick during throttle position changes. That's gone with these plugs. The jeep has excellent part throttle throttle response. Gear changes were also a lot smoother, as the motor would not tend to 'hang up' in RPM's between shifts.

I'm getting very good mileage -- definitely at the high end of the forum.

dmwil

I changed my plugs and wires today, and it wasn't as bad on that last plug as I thought it would be. Running the wires wasn't too bad, either. I just taped the new wire to the old one and gently pulled/guided it through.

The old plugs, with 58k miles on them, did not look too bad. The gap had increased to probably .055, so I could have reset the gap and run them further. No point in it, though, when new plugs are about $2 a piece with a rebate from Champion.

I found that my O'Reilly Autoparts plug gap gauge was about .007 off. My plugs would have been gapped wider than spec. I checked it against a gauge from Autozone and one from Advance Auto, and both of them measured the same, so I went with it.

The engine ran well before, and after a short drive today, appeared to run at least as well. We'll see after a week if there is any perceived improvement. I also cleaned the throttle body (yuck!!) and replaced the PCV valve, so the combination might produce a perceptible improvement.

One thing is for sure. I feel better about how it runs, so I guess that is what matters most. I'll plan on changing the plugs out again in another 60k miles. The new wires are supposed to be LONG lasting, so I might not change them until the third plug change, assuming I keep the Jeep that long. (I probably will, since I've got the lifetime powertrain warranty.

Biscuit

Not true. They're a normal wear & tear repair item. Read your warranty. It specifically excludes spark plugs.