I just put new plugs in my 04 Lariat Screw at 100k miles. About a month before that I started to get a vibration between 35-45 mph until it went into overdrive. After its in overdrive it does great. At a dead stop I can put it to the floor and there is no vibration. But if I drive casual it will vibrate between 35-45 EVERYTIME. I heard it could be a misfire.... My plugs were due so I changed them. Vibration still there. Im thinking coil packs. But which one??? I also have a Edge tuner. It does the vibration with and without it. Any ideas?


Thank you,
Chris in Texas

 

You didn't mention that the Check Engine Light Was on,Find someone/someplace that has a decent Scan Tool & have them look @ OBD 2 Mode 6 Data it should show info for each cylinder & if there are any misfire counts,A good scan tool will do much more than pull codes/data you just have to know the tool & where to look.

 

No, the engine light never came on. I was planning on taking it to a place that does a full engine scan. It tells you cylinder % the whole 9 yards.

 

I had the same problem over the summer...swore it was the overdrive.

Dealer installed a recorder for a week, and it didn't show anything. They finally found a misfire on cylinder 3 and replaced COP. Truck ran good until a few weeks ago...same problem. I bought one new COP, and am trying to figure it out. My ACTRON scanner doesn't show any codes, and no check engine light.

I started with cylinder 1. No more miss, but truck boggs down after shifting into overdrive...maybe multiple misfires?

Regards!

 

I guess when I have the extra money I'm going to replace ALL the COP's. I've put my programer on all 3 different settings and my truck still does the same thing. Thanks for all the input on this.