Rum, rum, rum@ 3,500 RPM
My E450 with V10 has a slight surging of RPMs at 3,500 and climbiing hills. Normal or something out of balance? New 8 months old 2015 chassis.
Forum Discussion
His "rum rum rum" title to me points to a harmonic vibration rather than a surge. A surge would be an uneven power delivery from the engine-slight change in power output when throttle is steady.
Just from what I read here, I'd say driveshaft vibration.
I will say on mine it has a very slight driveshaft vibration that it passes through at about 62 mph. I am *very* sensitive to driveline vibrations, and I dislike them. However I've chased enough of them to know when to ignore. This can be an expensive wild goose chase that resists solving. In the RV with the long driveshaft, the 4.56 axle which spins them fast, and the coach house box which can set up a harmonic vibration it can be a lost cause if you want pure perfection.
If it is under warranty take it back to Ford and ask them to check it. Maybe yours is so out of kilter they'll do something about it. Don't count on much if it is minor. JD who posted above me always has good useful suggestions.
Just from what I read here, I'd say driveshaft vibration.
I will say on mine it has a very slight driveshaft vibration that it passes through at about 62 mph. I am *very* sensitive to driveline vibrations, and I dislike them. However I've chased enough of them to know when to ignore. This can be an expensive wild goose chase that resists solving. In the RV with the long driveshaft, the 4.56 axle which spins them fast, and the coach house box which can set up a harmonic vibration it can be a lost cause if you want pure perfection.
If it is under warranty take it back to Ford and ask them to check it. Maybe yours is so out of kilter they'll do something about it. Don't count on much if it is minor. JD who posted above me always has good useful suggestions.
