RobWigglezz

We have two 99' f250 7.3L that we use regularly for work. One seems to have a problem holding a constant rpm when idling or any constant speed. It sounds like the turbo keeps building pressure and releasing it making the ""woosh" sound. It only goes away when you accelerate. We've replaces all the rubber conectors for the turbo, but that didnt do anything. The only mods are a 4" exhaust. The other 99' has 50,000 less miles on it and runs like a champ. Any insight would be appreciated.

dale7637

There are two things here that could be a problem. If the wastegate was sticky the turbo will spool up until it opens the wastegate and then release. I dont know a whole bunch about the 7.3's but i would think that the wastegate is part of the turbo. At an idle the engine really should not be working hard enough to make any boost, which brings me to my next idea. It is possible that an injector is stuck open somehwhat. I am pretty sure that the 7.3l ford is a Heui engine, but i am not familiar with the injection oil system. I am sure that there is somebody else on this forum that is a lot more familiar with it than myself. I know the Caterpillar Heui system very well, but not sure about the ford.

RobWigglezz

thanks for your help. i'll relay this back to my boss and see what he thinks. He's getting fed up because everyone just tells him it's just the nature of the beast.