Engine "whooshing" Sound

[redwoody]

hey guys, a friend of mine just bought a totally stock 2001 7.3, AT, 133k miles. it starts fine, seems to have good power for a stocker, but it has an intermittent "whooshing" or "shushing" sound. when idling cold or when driving it, we can hear a sound similar to if you were to put kitty litter in a steel pan and shake it back and forth. it seems to get a bit better/quieter when hot but will do it intermittently all the time but mostly just under load. any thoughts? have not pulled any codes yet - don't have a scan tool. the sounds does seem to be coming from near the turbo or exhaust. (I think I know what you're going to tell me but wanted to hear your ideas.) thanks.

[bigcountrysg]

I think you are talking about the Turbo. The sound you are describing is most likely the Wastegate releasing the excess boost from the Turbo. I never heard it when idling though. Also if you listen closely when you shut the truck down you can hear the turbo still spining and pushing air when you walk by the exhuast it sounds cool.

[vitalidle]

Could also be the exhaust back pressure valve sticking. I was reading that they can stick if they get sooted up.

[Turbodude]

EBPV sticking...slightly...tell him to really get after it one day...that might blow the carbon out.

[redwoody]

Originally Posted by Turbodude

EBPV sticking...slightly...tell him to really get after it one day...that might blow the carbon out.

that's about what we figured. we looked to disconnect it but was too dang cold to mess with it too much. funny how the sound is so intermittent. is very loud at idle when cold. fairly loud in the cab when driving too. can you tell me where the sensor is located? we'll try disconnecting it.
thanks.

I dont worry about it. It is for helping to warm your truck up in the cold.

[redwoody]

Originally Posted by Stroketechintraining

I dont worry about it. It is for helping to warm your truck up in the cold.

it's NOT normal for it (EBPV) to back up the exhaust when engine is hot/hauling arse down the road. the valve must be stuck partially closed or the sensor is acting up intermittently. funny thing, power is pretty good for a stock stroker.

[dkmunns]

yup, my '02 does the same thing when its cold. I bump the throttle and it quits.

[samiam]

if it's not quitting, could it be a bad torque converter?

[special_ed1977]

tighten turbo manifold boots and coller tube boots that should do it.