hi i am new to this but i have read some of the messages and this seems like a very good site i have a 1997 ford f-250 heavy duty 7.3 powerstroke automatic extra cab 4x4 i love the power of this truck runs and pulls real strong it has 166,000 miles on her i bought it in july 05 from texas had it shipped to new york i have noticed maybe coincidence but it seems in cold weather i have a loud wooshing under hood while driving say 25-30 mph in traffic and also when this noise occurs it fells like it bogs down push to go pedal and it seems to stop the noise for a minute and stop bogging i could be driving for hours on highway and come into town and it does it i run 5/40 mobil one formulated for power stroke cummins duramax etc. for diesels i don't know if that has something to do with it but it didn't seem to do it in warmer weather any advise would be greatly appreciated
thanks al73z28

That is the ebv exhaust brake valve that ford uses for cold weather warm ups when the weather is lower then around 38 degrees the computer will turn close a butterfly in the exhaust to aid in quicker warms ups. You probly have noticed that this goes away when the engine is warmed up. this valve also works very well for an exhaust brake. a wiring harness can be purshased or one can be made as I did with a toggle switch and a micro switch on the throttle pedal. If this is a problem and you do not want this to turn on when the engine is cold it can be unplugged and the engine seems to warm up as fast as with it plugged in. the plug in is located under the intake hose clamp for the turbo inlet near the left cylinder head.

this happens even when i drive the truck for a couple of hours what do you think?

I didn't think the 97's had the EBPV on them.

All 7.3 powerstrokes got a ebpv. Try unplugging it and see if your problem goes away. Its a two wire plug at the front right side of the turbo peditstal.

thanks for the advise i'll try unpluging and see what happens

yeah my 97 does it too I wired mine up to a switch and unhooked it from the factory wiring harness, it works really well for an exhaust brake and I can turn it on and off as I want to.