Have a 2001 7.3. Somewhat low on power and fuel mileage, so I built a fancy boost leak detector. When I used it, there was air coming out of the dipstick tube. No real boost leaks, but I'm just wondering if this is something I should worry about. Thanks, y'all!

 

Did you disconnect the CCV (tube connected to dog house)? I think you are supposed to pressurize straight to the turbo, otherwise you will pressurize your case I believe. I have heard about people bending something on their HPOP when it has too much pressure.

 

I don't know about air coming out of the oil dipstick tube, the only ways the air could get in there is if it is going thru the CCV if your test rig is connected before it, or past the rings of the piston with intake valves open. check blow-by (place oil cap upside down on oil filler neck and see if it blows of) (don't freak if it vibrates off). If that is all good I just had the same complaint with my 2001 7.3. One of the problems was a rather large exhaust leak where the stock up-pipes went into the Y-collector (replaced with international bellowed up-pipes) (the stock pipes fell right out of the y-collector without removing the bolts!). The other problem my dad suggested from experience with his '97. The throttle pedal position sensor was not operating properly but did not throw a CEL. When I changed it the truck went like new!