[XKJeep06]

Hi all! It's been a few weeks since we rolled over 30K miles on our XK. According to the service maintenance manual, I'm due for the following to-do's:

-Oil/filter change (petro mobile 5W-20 oil; done)
-Air filter change (not yet)
-Differential service (done)
-Replace spark plugs (not yet)
-Replace PCV valve (not yet... then again, where is it on the HEMI?)
-Fuel system service (thinkin of pouring a lucas gas additive cleaner on next fillup)
Check other areas....

Based on this, can you all provide me with some suggestions/recommendations. I totally forgot reading about the HEMIs using two plugs per cylinder (a whooping 16 spark plugs; a bit of overload compared to my Honda's 4 plug setup).

:ugh2:

 

[AKFossil]

(a whooping 16 spark plugs; a bit of overload compared to my Honda's 4 plug setup).

:ugh2:

Bigger engines = more plugs :eyemouth:

 

[Adondo]

Double plugs are for better burn and/or better performance.

Aircraft have always had two plugs per hole. When you do a ''run up'' at the end of the runway, you turn the key from ''both'' to ''right'' then ''left'' to switch magnetos. The RPM drops a bit as each second set of plugs turn off. They do make a difference.

 

[JJSEBASTIAN]

Adondo;
Really? That is cool! I didn't know that you could switch the banks of plugs on and off in airplanes like that... Makes sense for safety, etc... Also proves there is a performance reason too if the RPM drops as you say... Neat!

XKJeep06;
I am still on the original plugs(I assume as I bought it at 20,00 0miles) and I have 45,000 on them....(I KNOW I AM BAD!!!) I am waiting for warmer weather to arrive before I attempt it. I have heard it is not quick and easy! I think I'll just go with the OEM plugs. I haven't had much luck with aftermarket performance stuff in my other vehicles, so I'm not going to start now....

 

[Adondo]

It's also for safety reasons as things are generally redundant in aircraft. The typical ignition switch in a Piper, Cessna, etc. says ''OFF ACC LEFT RIGHT BOTH START''

The left/right refs a set of magnetos. (Usually a pancake six cylinder Lycoming) And... magnetos are used because they're not dependent on battery power like automotive systems.

A run up is when you lock the brakes and run up the RPM to check everything. (While you're working the yoke to check control surfaces too) The magneto check makes sure they're both really working. The RPM will drop a couple hundred or so when a set of plugs dies.

Obviously, the automotive industry has figured out the double plugs idea works pretty good. The 2009 4.7L also has double plugs... the usual set as before, (On top, down deep tubes) and a second set in the normal position found on other engines. The wire crosses the valve cover and taps into the coils on top.

Personally, I’m glad I have the older 4.7L. The way it’s packed into the Commander would mean a five hour job to replace that second set. The ones on top aren’t too bad to access.

 

[tripod]

im at 30k also. just did oil and air filter. the air filters are around 8 bucks, so i change them when i do the oil (until i get a CAI). used redline for the diff. dont know where the pcv is either. i imagine one on each valve cover? as for the plugs ive been eyeing the NGK G power single platinum (5017). the full platinum are too much. the single are only a buck more per plug. rockauto has them cheapest ive found so far. ive used berrymans fuel system cleaner in the past P# 2630 and it worked awesome. thinking about tryhing it , but not sure how sensitive the MAF is

 

[XKJeep06]

im at 30k also. just did oil and air filter. the air filters are around 8 bucks, so i change them when i do the oil (until i get a CAI). used redline for the diff. dont know where the pcv is either. i imagine one on each valve cover? as for the plugs ive been eyeing the NGK G power single platinum (5017). the full platinum are too much. the single are only a buck more per plug. rockauto has them cheapest ive found so far. ive used berrymans fuel system cleaner in the past P# 2630 and it worked awesome. thinking about tryhing it , but not sure how sensitive the MAF is

Yeah, I'm about to pick up a new Fram or Purolator aif filter some time this week. Regarding spark plugs, considering getting some Autolite platinums. NGKs I'm sure work well with imports (like my Honda). Germans I believe use Bosch products. I'm curious to hear what others have experienced with the other available brands out there.

 

[bob123]

My 3.7L V6 came with stock NGK V-Power plugs. I had the dealership replaced them with stock at around 35,000. I am glad I did too because the plugs look worn. You can hardly see the groove.

However, I still asked for the stock plugs. I should have spent a little more for the double Plat. NGK plugs.

I believe the fuel service is bs. As long as you dump a bottle of fuel injection cleaner in your tank every six months, it should be good. Just think, the Commander only has around 30k.

 

[CUPRA]

I got a price at the dealership for the 30k service yesterday (I am 5k miles away from that now) for $629.

 

[lekmedm]

I am still on the original plugs(I assume as I bought it at 20,00 0miles) and I have 45,000 on them....(I KNOW I AM BAD!!!) I am waiting for warmer weather to arrive before I attempt it. I have heard it is not quick and easy! I think I'll just go with the OEM plugs. I haven't had much luck with aftermarket performance stuff in my other vehicles, so I'm not going to start now....

On the Hemi, quick - no; easy - well, not too bad. If you have an assortment of extensions and universal joints for your socket, accessing the plugs isn't too bad at all. The worst part for me was pulling off 2 of the coil packs. The boots wouldn't let go and 1 for each of 2 cylinders was left in the tube. It was a royal PITA to get them out. In the end it seems there wasn't quite enough grease on the boot, so the rubber stuck to the plugs. I transferred one boot from one coil pack to the other, and then bought 1 new coil pack (I couldn't find a source for just the boot).

Just remember to use dielectric grease on the boots when you've replaced those plugs! It'll make the next time easier.

 

[SDBaja]

I got a price at the dealership for the 30k service yesterday (I am 5k miles away from that now) for $629.

Just to show the disparity, i got a 30K quote from Rancho San Diego Jeep for an astonishing $1248! It included transmission, front and rear diffs plus plugs. I was thinking extended warranty but with those prices I won't give them any future business. Good Grief!

 

[Jax]

The Plugs are due at 30K??? WOW!! The only thing I can thing of is WHY?
I thought all engine would go 100k on a set.

What makes this one eat plugs? Do we have to change the points and condnenser too?

 

[SDBaja]

The Plugs are due at 30K??? WOW!! The only thing I can thing of is WHY?
I thought all engine would go 100k on a set.

What makes this one eat plugs? Do we have to change the points and condnenser too?

Thats what most of us thought also. After reading through numerous posts though I am inclined to agree that they should be changed. It's electronic ignition..no points or condenser that I am aware of. The larger debate seems to be about which type of spark plugs to use.

 

[jcoulter]

I thought the same. Doesn't everything come with 100,000 mile plugs? Guess not.

 

[bob123]

I guess the next step would to upgrade to a platinum or an iridium plug. They are a much harder metal. I have a set of NGK laser platinum plugs on my other vehicle and they can last around 100,000 miles.

 

[bob123]

Has anyone upgraded their plugs? Any feedback?

 

[SDBaja]

I did the 30K service at Jiffy Lube.
front diff-$49.99
rear diff- $49.99
trans case-$49.99
oil- about $55
tire rotation-$20
4X4 signature service-$37

They used the manufacturer recommended lubricants including the Mopar transfer case fluid. I also did the full synth oil and tire rotation for $273 versus $1248 that Rancho Jeep in San Diego wanted. I then purchased 16 Champion double platinum spark plugs for $68. Those I will change in the next week or so. I saved almost $1000.

With the saved money I will go buy the kids new clothes.

 

[VooDooPlanksta]

Does anyone have any recommendations/guidelines for how to changing the transfer case fluid? I'm at the30K mark now and was wondering is this something I could tackle at home.

 

[rpgpgmr]

EASY job ... just did it 2 days ago. Run to Wal-Mart and get one of their $4 orange pumps in the automotive section if you don't already have one. You'll need it to pump the new fluid in.

1. Some guys use aftermarket fluid for the transfer case, but I went to the dealer for mine (You'll need 2 bottles).
2. The drain plug on the transfer case is on the bottom (of course) so just unscrew it (A 12mm bolt I believe) and let it drain for 10 or 15 minutes.
3. Plug it back up and unscrew the fill plug (it's just above the center).
4. Use your handy Wal-Mart pump to put in the new stuff.

That's honestly all there is to it.