COIL "D" on a 1998 ford Expedition Eddie Bauer 5.4

[sonmisojos]

I have been having so many problems lately with my truck. Right now its driving rough, it shakes a little while im driving, once i get past 50mph the shaking settles a little. When it goes below 50 mph the shaking is worse. I took it to Advance Auto and Auto Zone and they tested it and the code came back as Coilpack D. Does anyone know what that means? The people at the auto store couldn't tell me. My dad worked on my truck and the check engine light went away so the mechanic can't check it to see what's wrong; he told my dad to drive it around until it messes it up again. I'm so aggrivated. It's still driving rough even without the check engine light on. Any suggestions? Thanks

 

[KWT2000]

coil d thats an obd 1 read out and i would try another parts store and see if you can get history codes my guess is coil #4 is bad and you may be due for tune up... keep us informed

 

[sonmisojos]

My dad doesn't want to replace the coils unless he knows which one it is. I thought it could be Coil 4 but I'm not good a mechanic. The check engine light still isn't on so they can't check it when it's off. They did check it at the mechanic shop and it read that the truck was fine. We have changed coil pack number 2, we put in all new spark plugs. The first problem was the switch on the transmission and that was replaced and worked fine. Now the ABS light is on, we replaced the brakes and got new tires; I think it needs a sensor but I was told that wouldn't cause the shaking.

 

[KWT2000]

have you checked the pcv line from the valve cover to the back of the intake.??? the rubber elbow at the intake wears a hole in its self and the rubber part at the pcv can crack...also clean the mass air flow sensor and idel air controller this may fix the problem. if it was a coil it would have caused a CEL by now... does the CEL come on when you turn the key from off to on?

 

[Stoned06]

If it's a coil and the CEL didn't trip, try accelerating fairly quickly. That will set it off if it is indeed bad. IAC, PCV, and any rubber elbow/line where unmetered air can enter the system or cause a vacuum leak can be the culprit as well.

 

[sonmisojos]

He has checked the PCV and we have cleaned the IAC, the EGR. The CEL is on now. He took the truck to the mechanic and he checked the Coils and said that they were all fine. My dad is going to check the plugs again this weekend to see if maybe they were put in wrong. There's nothing else we can think of right now. I will keep you guys posted. Thanks for your suggestions.

 

[Stoned06]

Get the new CEL code diagnosed and go from there. Without that, you're shooting blind.

 

[sonmisojos]

Well, its fixed! Thank goodness. It was the coil 1 and 2....my dad had them in wrong or something, all he had to do was switch them and it fixed the problem. Thanks everyone for your suggestions.

 

[Stoned06]

Good to hear. Must not have been seated all the way down on top of the plug as it doesn't matter which plug they go on. Glad it was an easy fix.