6.4L engine noise

[jonathanrayce]

I have a 2008 6.4L powerstroke that had a radiator leak. I replaced it, but another problem I noticed was a sound coming from behind the radio. It is like a blowing noise. I did a search on here and have not found my problem yet. It sounds like gurgling under heavy load and then a blowing noise if I stay in the throttle. Under normal load there is no noise. No soot around the up pipe, no soot around the turbos, and no soot around exhaust. Anyone seen this?