Hey Guys
Been lucky so far with easy fixes on my truck thanks to your help. Think ive finally run into something that is gonna be a little harder. Whenever my 01 7.3 is under a pull or acceleration the motor pulses like you were pushing the gas pedal up and down. It doesnt jerk and cant feel it in the truck much just mainly hear it. As soon as I get on a strait road and just keep the truck moving it has no problem. If anyone has any ideas i'd appreciate the help.
Thanks

 

It sound like turbo surge. What re you running for a turbo? Stock? if so a WW or an ATS housing will take care of that. With the WW you will loose 1-2 # of boost and she will smoke a little more. That is per my experience when I had installed one.

 

now that you say that is does kind of sound like the turbo. So what would cause this? It is a stock turbo. replacing it the only real fix?

 

No, just swap out the compressor wheel. You are noticing it more I would guess because of the load from your tire size. Have you re-geared?

 

Well this one is on my F550 work truck with a utility bed loaded down with tools. So when its accelerating its pulling a lot. What would you mean by the compressor wheel?

 

Compressor wheel is the side of the turbo that compresses the incoming air, visible with the intake tube out of the way on the drivers side of the turbo.

 

Aight thanks. I know which one your talking about now. Is that the one everyone does the wicked wheel conversion to? What is going bad on it that would cause it to do this?

 

There is nothing going bad on it that causes it, It is just how the compressor map is. The condition known as turbo surge or stall occurs under heavy load conditions where boost pressures are elevated. The root cause is generally an imbalance of essures between the turbine side and the compressor side of the turbo. When the forces on the turbine are no longer strong ough to drive the compressor side of the turbo adequately, stall occurs. Often on Powerstrokes the stall will manifest self as a surging and the boost pressure in the manifold will fluctuate as the vehicle surges and you can hear an audible cyclic sound which corresponds with the surge.

 

Is this similar to the sound you are hearing if so it is surge and at a minimum a wicked wheel is the first cure for most.
YouTube - 1999 Ford F350 7.3 Compressor Surge

 

Well it actually sounds nothing like that. If your referring to the fast cycling sound at the end. It cycles was slower than that and you can hear the lifter rattle go up and down with it. The cycles would last at least a sec or a little longer.