Pulled new bass boat (3500 lbs) from Iowa to S Texas. About half way here I noticed a surging sound in the exhast and seemed to feel it also. I was on flat highway and not moving the throttle. Ay ideas? Coil, fuel filter etc??
Thanks
Dave

 

Possibly the EGR ? A bad EGR or whatever that thing is that controlls it will make it open and close at the wrong time. Very noticeable when cruising at a constant speed on the freeway. Sorta like a pulsing/surging thing. (When ford egr systems act up they don't nessessarily throw a code and light up the check engine light.)

To check and see if it is the egr system, just disconnect the vacume line that runs to it and cap it off. Take truck for test drive with boat to see if it still does it. Check engine light will come on..... but don't worry about it. All your trying to do is see if it's still surging/pulsing.

Hope that helps, give you at least one thing to check anyhow.

 

Got one for 27 bucks @ Autozone. We'll see if it works. If the tranny throws a code will it set the CEL or just store it. Disconnected all the COPs one at a time while engine was running and noticed a miss each time. Probably #3 going again. If it is a bad coil; do I have to change the plug as well? I wish I could find some one who wanted to trade for a F250 diesel!
Thanks
Dave