New plug on right, lower bank 2 plug on left


Started getting a P0300 and various missfire codes for random cyclinders. Truck has 95,000 kilometers so figured I would change the plugs. Several of the plugs on the lower bank on both sides were pretty much toast. Most of the plugs on the top looked good. All of the plugs had a small deposit where the spark hits the ground probe. Picture is typical plug from lower side. changing the plugs should make a big differance in how she runs and eliminate the codes.

Took right on 4 hours same as dealer said it would. I would have got it quicker but it was not a race.

 

95,000 Km is less than 60,000 miles; tell us more about your truck (year, engine, etc).

 

2011 F350 CC, 4x4, long box 6.2 95,000 kilometers. I have owed this truck for only 3500 kilometers so don't know any history.

Started feeling low on power when towing my boat (3500 lbs) or travel trailer (7500 lbs). Pulled a big hill with the travel trailer and it started missing and the engine light started flashing. Miss went away at the top of the hill but engine light stayed on. Checked for codes and got P0300 and a missfire code on a couple of cyclinders. Same thing happened a while latter while towing the boat and same codes showed up.

I cleaned the MAF, changed the air filter which needed it, checked for vacum leaks, there where none. Drove it for a while but same issue when under heavy load. Next on the trouble shoot list was plugs.

Have not driven it with a load yet but based on the look of the plugs I am pretty sure they were the issue.

Overall changing the plugs on this truck was not that difficult, just time consuming. The plugs on the COP where very hard to get off so I just left them pluged in and move them to the COP to the side. It takes several differant lengths 3/8 extensions, I did not have a 3/4 inch or or a 1 inch extension and either would have been handy to get just right clearance for the ratchet. All the plug wire boots and COP boots came off easy. Many of the plugs felt dry as they threaded out but came out with moderate effort. I used marine never-seez on the threads and some dielectic grease on the plug boot area when putting it the plugs in. All the plugs could be toruqed with my 3/8 torque wrench except the back passenger side. The one thing I realy wish I had to do this job was a topside creeper. Man it's hard on the knees and chest working inside the engine bay.

Over all I saved about $400 in labour doing this myself.