Hey all,

The other night my 01 f250 SD threw a #4 Misfire code. Got under the hood and proceeded to try and diagnose the problem. In getting under the hood I figured I would change the spark plugs while I was under there. A little background info.... the misfire started after a heavy rain storm with my truck parked in my driveway which is probably a -30 degree grade. I assumed the misfire was due to water getting into the hole where the boot and plug sit. I took the boot out and not to my surprise there was moisture on the boot and COP. I switched the COP with another cylinder (#1) and the code did not move so I was pretty set on the plug being the actual problem. I blew the hole out using an air compressor and used a little carb cleaner. I took the plug out, cleaned it up a little bit and placed it back in the threads, attached the COP and proceeded to get a Ignition Coil Circuit code (P0354 I think?) on that same cylinder. I figured I would change the plug out with another plug to make sure it wasnt the actual plug itself. I went to remove the #1 Spark plug but my spark plug socket wouldnt fit! I was dumbfounded and I just quit for the night. Im dying to fix this and tune this thing up any help would be greatly appreciated. Thanks in advance!!

 

The COP isn't plugged in so as to make an electrical connection. Check for damage to both sides of the connector.

Your spark plug socket go on a diet or shrink? Check the hole for anything dropped down there. Check it to see if it's been replaced with a "wrong" sized plug, perhaps from a spark plug from a thread repair kit.

 

The socket wont fit in the hole, or the socket wont seat onto the plug?

If the socket wont fit in the hole, use a thinner-walled socket.

If the socket wont seat on the plug, take the rubber out of the socket and see if you can get it to fit that way. If you can then just put the rubber back in and give it a bit of spit so it slides down over the plug.

 

Im going to take it apart tonight again, I will shoot some pictures. When I looked down at the plug it appeared as if the hexagonal "nut" looked more like a circle with 2 little "nipples" on either end

 

It feels as if the socket wont fit into the hole. Going to try the thinner wall idea as well

 

A standard 15 mm 0r 5/8" deep well socket should fit the stock-sized plugs.