1999 psd loss of boost and loud hissing sound ????

[tnhotrod]

My Truck Is A 1999 Psd And I Can Be Driving Down The Road And Feel The Loss Of Power Then Look At My Boost Gauge And I Have No Boost... Then I Noticed A Loud Hissing Sound Any Help Or Suggestions...thanks

[sldghamr]

i have a 96, when at 65mph i have only 5 psi of boost. if i were to let off the throttle, i have no boost. it might not be ur turbo. check codes if u can. what r u doing when this happens??? towing,cruising etc..........

[Turbodude]

hey man that sounds like the classic closure of your Exhaust back pressure valve. If you go into the 7.3 tech files and read the winter what to expect from your truck it explains this device. If you have no codes or anything i wouldn't be worried about it.

[SCUFFY828]

sounds to me like you blew off an intercooler tube possibly ,would be very ow on power and no boost

[kefier2001]

Check you intercooler tubes, clamps. Do you have boost at all?? Or does it just do this every now and then, or when it is cold?? If that is the case, it is probably the EBPV, closing up on you to keep the truck warm. You could disconnect it if you want, or take off the turbo and remove it totally! Just my two cents!!

[tnhotrod]

It Has Only Done This When Cold So Far... Where Is This Line At I Need To Disconnect? Thanks

[SCUFFY828]

now you tell us, just kidding , definitly ebp valve shutting off

[kefier2001]

There is a connector at the bottom of your turbo. If you have a Haynes or Chiltons manual, you can look it up. There should be some other threads on this site with the pic of the connector. Good luck with it!

[dereku]

I have a 96 7.3 and im not too familiar with the 99 but im sure their all about the same, i had that problem once and i noticed on the outlet side of the intercooler just before the tube reaches the engine there is what looks to be a vacume hose running to a sensor and if that fell off that could be it