I HAVE A 2012 GC OVERLAND WITH THE 5.7 HEMI. I'M CHANGING the spark plugs my question is what do you coat the coil with ? Is it the die-electric grease or something else ?

sounds like battery. when a car battery dies it is dead wasting time trying to recharge it.. Turn headlights on bright, turn heater blower motor on high watch lights, do the stay bright or start dimming. Try to start car with lights on are the going dim. If the headlights do not remain bright while starting car it is battery.

possible causes for code P0300
you've already change coil and plug....

P0300 could be bad #3 plug or coil... switch those also and see if code change..

if it persist try the next thing..

I would try trading fuel injector 4 to 5 and putting 5 into 4 and see which code you get.....

• Faulty spark plug (s)
• Faulty ignition coil (s)
• Clogged or faulty fuel injector (s)
• Intake air leak
• Fuel injectors harness is open or shorted
• Fuel Injectors circuit poor electrical connection
• Ignition coils harness is open or shorted
• Ignition coils circuit poor electrical connection
• Insufficient cylinders compression
• Incorrect fuel pressure

code P0305 is simmilar....

• Faulty spark plug 5
• Clogged or faulty fuel injector 5
• Faulty ignition coil 5
• Fuel injector 5 harness is open or shorted
• Fuel injector 5 circuit poor electrical connection
• Ignition coil 5 harness is open or shorted
• Ignition coil 5 circuit poor electrical connection
• Insufficient cylinder 5 compression
• Incorrect fuel pressure
• Intake air leak

The 2012 5.7 Hemi firing order is:
• Coil...1-8-4-3-6-5-7-2
• Plug..6-5-7-2-1-8-4-3

top cylinder head under the coil pack ignition. electronic system. / never heard a hemi with 16 spark plugs lol.

There are only 8 spark plugs there are also 8 coil packs over the spark plugs the you need to remove to get the spark plugs out

Sorry, Mazda has not released specific information about the 2012 models to the aftermarket yet. The nearest I could come up with is for a 2010 Mazda 3i (I am sure it is probably similar).

> Remove the plug hole plate from the top of the valve cover assembly
> Remove ignition coil assemblies
> Remove spark plugs
> Installation is reverse procedure

With all that said, it is not necessary to replace spark plugs in your vehicle for 100,000 miles. I find it hard to believe that your 2012 car could possibly need spark plug replacements at this early age.

Sorry, Mazda has not released specific information about the 2012 models to the aftermarket yet. The nearest I could come up with is for a 2010 Mazda 3i (I am sure it is probably similar).

> Remove the plug hole plate from the top of the valve cover assembly
> Remove ignition coil assemblies
> Remove spark plugs
> Installation is reverse procedure

With all that said, it is not necessary to replace spark plugs in your vehicle for 100,000 miles. I find it hard to believe that your 2012 car could possibly need spark plug replacements at this early age.

the most important (in my opinion) is changing the transmission fluid( transmissions for those cost about $4,000.00 to replace) its supposed to be changed every 30,000 miles. ( spark plugs can last up to 100,000 miles before needing replaced.)

I'm assuming this is a 5.7 hemi. Remove the 8 coil packs that are bolted to the top of the valve cover. You can do 1 at a time. Each coil pack has two spark plugs under it . use a 5/8 spark plug socket and extention. If its a 4.7 the coil packs are held on by one 10mm nut. These packs are just inside the valve cover on both sides of the engine. There will be only one 5/8 plug for each pack

My dad had a 93 GC and he had to replace somekind of crankshaft sensor then it was fine ever since. I guess those inline 6's are known for that.