I get this code about once a year. I pull the number 3 plug out and it looks and smells (yes I sniff it) good. I normally change it with a new plug, and change the plug wire with an old one that I can't seem to get rid of, and it's good for another year or in my case about 30k miles. Could the coil be going bad? I bought another set of plugs and wires (Motorcraft) and will put them on tomorrow, but just wondered if this recurring problem is something else. This has been by far the best work truck I have ever had. It has simply been a great truck.

Back to the sniffing. Yes, every good mechanic has his own way of checking for problems. Mine is sniffing, looking, touching, feeling, tasting, smacking, shocking.....you understand.

1997 F150 supercab, XL, LWB Auto 4.6 with a whop-ping 315K miles and climbing. Runs like a scalded ape. Uses about 1 quart of oil between changes. In other words, I install 1/2 quart at 1500. I believe in Christ, good maintenance and Duralube every 4th oil change, 93 octane if your gonna pull something and those new flourescent light bulbs on the outside of my garage door. Works for me.

 

Smell your EGR and see if it needs cleaning. I have seen the EGR cause a misfire on #3.

 

 

EGR and TB passages are clean.

 

.....new motorcraft platinum plug and a new wire....back to normal. I checked the old plug for any form of moisture, checked for any smell of antifreeze, oil, nothing. Course, when the check engine light starts flashing, and it runs awful, enough gas has flooded the cylinder, it has washed away the culprit. Plug looks like a normal 30k mile plug. It looks like it should work. I guess when it finally goes, I'll find the problem. Checked radiator fluid for signs of fuel, none..............Mystery.....

 

I just had a recurring miss issue in #3 on my V6 - a new coil pack fixed it.

 

GLC, I think I might need to do the same. It is too consistant. I think I am going to replace both of them. They've probably done their share.

 

At 315k miles, those coil packs don't owe you a cent.