When to Change Spark Plugs on Hemi?

[GPintheMitten]

Like the title says, when? Mine seems to run great but maybe I should get it done. I probably should have done it sooner ...hate to admit but I have 85,000 miles on original plugs.

[LWM]

The upper 8 plugs are due at 30,000 miles, I cannot remember the the miles for the lower 8 plugs but someone will find it I am sure. But my bet is at 85,000 you might as well do them all.

[GPintheMitten]

Ooops. OK. I'll do all 16. Seems like my dealer may have mentioned that. I service it at the same dealer all the time. Oh well, my bad.

[07JeepXK]

Your deffinately a little over due for some new plugs. Maybe you'll even see an increase in gas mileage when you swap them out.

[GPintheMitten]

Well, I've done a good job of other maintenance, fluids and brakes. Time to get this handled. Color me red.

[GPintheMitten]

Just got back from getting new plugs. I had forgotten that I had them done at 50,000 miles, so not as bad as I thought.

[LWM]

Just got back from getting new plugs. I had forgotten that I had them done at 50,000 miles, so not as bad as I thought.

Then I guess you are not a far overdue as you originally thought. If you think about it take some photos of the plugs you remove so we can see what they look like after 35,000 miles.

And if you feel like making a "How To Change Hemi Spark Plugs" thread for the tech section we would all be greatful!

[GPintheMitten]

What I meant was I just got back from the dealer and had them put new plugs in. Sorry 'bout that. I did think on the way home I should have asked to see the old plugs.

[lekmedm]

The upper 8 plugs are due at 30,000 miles, I cannot remember the the miles for the lower 8 plugs but someone will find it I am sure. But my bet is at 85,000 you might as well do them all.

You are describing the plugs in the 4.7L engine and not the Hemi that GP has. On the Hemi, all the plugs are on the top, side-by-side. In fact, there is a single coil pack per cylinder that has 2 boots coming out for the 2 plugs per cylinder. When I was changing my plugs, it was difficult to pull the coil packs off of 2 of the cylinders. On both of those, each coil pack left 1 boot in the cylinder head. It was a royal PITA to get them out! Make sure to use dielectric grease on the boots when reinstalling!

BTW, I did my plugs at 30,000 and put in Autolite Iridiums. With conservative driving, I can get 19 - 21 mpg on the highway with gently rolling terrain.

[LWM]

You are describing the plugs in the 4.7L engine and not the Hemi that GP has.

Thank you, In time we will get a photo "how to" posted up on the forum. I only have 16,000 miles so I still have 3 or 4 years to go before I get to 30,000 miles

[07JeepXK]

Thats funny. I put over 20,000 miles on my XK each year.

[pjmjr508]

lol So far I got mine in Aug of last year with 26k & now its at 36k so I am close to 07jeepkx on the amount of miles with in a year.

[LWM]

I purchased 16 plugs on sale for $3.00 each but since I only have 20,000 miles I am in no hurry to install them.