lumpdog
Member
- Joined
- March 29, 2005
- Messages
- 12
- Reaction score
- 0
- City, State
- Mountain Home,ID
- Year, Model & Trim Level
- 94 Explorer
Ok, better start off with some background here. I have constantly had issues with my girlfriend's 4.0 running, ummm, weird. It used to have this cold engine surge that was really annoying. I spent hours chasing it, scanning it, and testing everything. BTW, I am a certified tech, just don't have much experience with Ford systems (I am a GM trained, and that's what I own, and I find it a little difficult to understand why the Ford diagnostics are so crappy??) So, I have a lot of friends in the business, and one of my good friends is a Ford driveability tech who has been working at the local dealer for almost 20 years. We spent almost an entire weekend and came up with nothing. Tested and inspected everything, and finally replaced the MAF, and if made it a little better, at least livable. It is a kick in the ass to have access to all the Ford tools and a tech for free, but I sure wish I could figure out why this thing is being stupid.
And now to the ongoing problem. It started missing again, and I found the inside electrode insulator on the #4 spark plug cracked (first time with the cracked insulator). The insided part around the electrode was split perfectly in half, still intact, and causing the miss. The plugs I pulled out were Motorcraft replacements. I constantly have issues with the plugs. #3 and #4 are always the ones giving me issues. They always come out really hard, even though I always antisieze the threads. There is always a extremely foul smelling soot that is in the threads of those two plugs. Also, those two plugs always seem to look brand new, like they are running lean compared to the others. The other 4 plugs always spin out freely, and always look like the should. I have tried different plugs like NGK, Bosch, AC Delco, Autolite(hate those plugs, but gave em a shot anyways), and Motorcraft. I have even tried platinum and non types. I am a technician and have never seen or smelt the nasty "soot" only on the threads of anything before, and neither has my buddy. We have called Ford Technical Assistance with no luck. The plugs that are having the problems are in the same port of each head, and I am wondering if there is some sort of casting problem with the cylinder heads that has the exhaust baking the spark plug threads. I know everyone is going to say that I have a plugged injector, but we have switched injectors with neighboring cylinders and the problem persists. And we always run a good grade of only Chevron fuel in it.
Emissions tests always come out clean, and I have compression tested all the cylinders with no problems there.
Has anyone else noticed that the #3 and #4 spark plugs are having problems??
And now to the ongoing problem. It started missing again, and I found the inside electrode insulator on the #4 spark plug cracked (first time with the cracked insulator). The insided part around the electrode was split perfectly in half, still intact, and causing the miss. The plugs I pulled out were Motorcraft replacements. I constantly have issues with the plugs. #3 and #4 are always the ones giving me issues. They always come out really hard, even though I always antisieze the threads. There is always a extremely foul smelling soot that is in the threads of those two plugs. Also, those two plugs always seem to look brand new, like they are running lean compared to the others. The other 4 plugs always spin out freely, and always look like the should. I have tried different plugs like NGK, Bosch, AC Delco, Autolite(hate those plugs, but gave em a shot anyways), and Motorcraft. I have even tried platinum and non types. I am a technician and have never seen or smelt the nasty "soot" only on the threads of anything before, and neither has my buddy. We have called Ford Technical Assistance with no luck. The plugs that are having the problems are in the same port of each head, and I am wondering if there is some sort of casting problem with the cylinder heads that has the exhaust baking the spark plug threads. I know everyone is going to say that I have a plugged injector, but we have switched injectors with neighboring cylinders and the problem persists. And we always run a good grade of only Chevron fuel in it.
Emissions tests always come out clean, and I have compression tested all the cylinders with no problems there.
Has anyone else noticed that the #3 and #4 spark plugs are having problems??
