I was surprised that the plugs in the 5.7 Hemi had to be changed every 30k.

I thought nowadays the plugs were platinum and didn't require changing until 100k.

 

It was my understanding that only the plugs that operate during the MDS mode need to be changed every 30k miles. But I don't think they are using platinum plugs, I think they are the copper core plugs that are recomended. Haven't completely read the owners manual yet so an only going by what I've read on the forum. Jeff.

 

why would they recomend copper plugs?

i can see them putting in copper plugs just to kept cost down but i am going to put platinum plugs in mine when the time comes. unless there is some odd reason that copper plugs should be used

 

I was taking my truck to be run on a dyno once and while talking to dave we started discussing the 04 chevy truck in the parking lot that had holes in the pistons. He had installed a supercharged for the previous owner and said you have to run colder copper plugs only. The guy traded it in a few years later and the dealership desided to give it a "tune up" and installed factory heat range platinum plugs and it melted the pistons then the dealer was trying to get dave to fix it for free. Any how dave made it clear that platinum was for daily drivers that needed to make it out of warrenty and the coppers were in all his performance engines he built and tuned.

 

Are we sure about the copper? I know that was the case on the 3rd GEN, but I thought I read somewhere the new Hemi gets platinum.

 

OK, now I'm confussed. I picked my new truck up on Monday. Was reading the OM last night and the only reference it makes to changing upper spark plugs and lower spark plugs in for the 4.7L engine. This is on page 470 of the OM (does not list a publish date, but shows copyrighted 2008 and Third Edition). Under scheduled maint it shows the 5.7L engine having plugs changed at 60k miles, then shows them change at 60k miles intervals after that. Plug type is LZFR5C-11 with a .043 gap. However, I can not seem to find this plug on google. Google brings up a bunch of refs to ZFR5C-11 for Honda though. So I can't tell if this plug is a platinum or copper or what. Guess I'll have to check again when I get close to the 60k mark. Jeff.

 

From the OM. Hemi 5.7 requires plugs every 30K. 4.7L requires plugs (8) at 30K, 8plugs at 102K.

Required Maintenance Intervals
NOTE: ** Vehicle’s built with the 4.7L engine are
equipped with sixteen spark plugs. One set is located on
the top of the engine under the coils and the second set is
located on the side of the engine.
The spark plugs located under the coils are a standard
plug and must be changed every 30,000 miles
(50 000 km).
The spark plugs located on the side of the engine are a
premium plug and must be changed every 102,000 miles
(170 000 km).
480 MAINTENANCE SCHEDULES
8
MAINTENANCE
30,000 Miles (50,000 km) or
30 Months Maintenance
Service Schedule
❏ Change the engine oil and engine oil
filter.
❏ Rotate tires.
❏ Replace the engine air cleaner filter.
❏ Replace the top row of spark plugs (4.7L Engine).
❏ Replace the spark plugs (3.7L and 5.7L Engines).
❏ Inspect the transfer case fluid.

Spark Plugs – 4.7L Engine Upper Bank — FR8TE2 (Gap 0.039 in [.99 mm]) Lower Bank — FR8T1332
(Gap 0.051 in [1.30 mm])
Spark Plugs – 5.7L Engine LZFR5C–11 (Gap 0.043 in [1.09 mm])

 

Stock plugs are platinum. I switched to NGK Iridium.

 

This reminds me of somthing similar ford does to there 4.0L V6 engine. When built at the factory, they use 3 double platinum spark plugs on the drivers side, and 3 regular platinum (non platinum tipped) on the passengers side.

People argued and argued that they are for performance reasons, and related to the way they are fired off. (the side that has the double plats get some kind of reverse fire) And this was partly true:

The truth was however, one side did only need regular platinum plugs to reach the 50,000 miles change interval, and the other side DEFINATELY needed double plats, because it would eat up regular plats quick if they were on that side. BUT once you bring it to ford for new plugs, they use double platinums for ALL 6, and don't even carry the PN for the single plats. Because, why not just use the same FORD PN all the way around? It gets the double plats where it needs it, and also gets some overkill on the side that doesnt need it. Why mess around with two part numbers and risk mistakes? If you just do dbl plats everywhere, you cant go wrong.

It was to save money during production. They figured, well its comming in a 50k for new plugs anyway, so why waste money during production? The dealerships however does not follow this nonsense.

My dakota came with coppers. Everyone argued that copper was required blah blah, put in platinums and it will loose HP and run like ****. I put in double plats and it runs exactly the same. Now I don't have to take them out every 30k. To each there own I guess!

 

Plugs at 30K. All 16 of them? The owners manual should be required reading before purchasing the Hemi. I have a ford Taurus that just hit 100,000 miles and I have never changed any plugs. The car runs as good as the day I bought it. The mileage is better.

16 spark plugs! What the F**K where they thinking. I do not know much about engines and rolling mechanical work, so I will be needing the dealer to perform the maintenance.

I probably still would have bought the truck, but I definitely would have asked many more questions before I signed that check.