I finally had some spare time to change the spark plugs in my 2009 Ram Hemi. I was at 105,000 km (65,000 miles) so I was about double the recommended interval for changing them. Truck was running great although gas mileage had been off a bit lately.

It wasn't that difficult to change out the 16 plugs. As noted by others, the 2 plugs on the passenger side closest to the firewall are difficult to access, as are the 4 plugs on the driver's side closest to the firewall. It took me about 2 1/2 hours total which included gapping the plugs, and a beer break after changing 8 plugs. It's more time-consuming than difficult.

I was surprised how good the old plugs looked. A nice light "coffee brown" color and no build up of deposits. (Of course, I still remember changing spark plugs on 2-stroke oil injected motorcycles so the plugs on a modern 4 stroke are definitely going to look a lot better...). The only thing I noticed was that the gap on the old plugs was out of spec...significantly larger which isn't surprising.

Based on the condition of the plugs, I simply don't see the logic in changing them at 30,000 miles (50,000 km). I essentially went double that and my plugs still looked good and my truck was running great. When I've put 50,000 km on my new plugs I think I'll pull one or two and have a look, but if they look fine I'll change them out after 100,000 km.

 

My plugs were looking fine at 80***kms too. I think the big worry to my understanding is them seizing and breaking off during the removal.

 

That's a possibility. Three or four of my plugs were in pretty tight...lot of torque to get them out. Fortunately, they weren't the back plugs against the firewall which are a pain to access. I made sure when I put the new plugs in that I didn't over-tighten...just snugged them up. Very long fine thread so I don't see the plugs loosening. I didn't use anti-seize as the plugs have a special coating on the the threads that is supposed to prevent binding.

As good as my plugs looked for 105,000 km (65,000 miles) I did check the gap on a few of the ones I removed and in each case the gap was larger than spec'd. Since changing my plugs my gas mileage has come back up a bit too.