Just did intake/EGR clean out: now have new sound

I just used deafbug's how-to to clean out my intake manifold and EGR. Things went smoothly and I estimate things were 60% clogged with residue.

First, let me say I am shocked by how much more responsive the car is. Whe I step on it coming from a dead start, it is at 4,000 rpms in a heartbeat. I actually have to pay attention now to not burn out.

The reason for the post is this... There is now a new sound that I get about mid-way through a sustained acceleration. Could be described as either almost a belt squeal type sound, but not really. Maybe a whine? Or, like someone sipping/blowing air through a straw. If I back off, it immediately goes away.

Is this the turbo spooling up? People say you can hear the turbo spool up, but I had never been able to hear anything before.

When I cleaned out the EGR, there was so much crap around the valve, I'm not sure it could actually close. Now that it's able to close, would this possibly create more suction or something that would be causing the noise?

There is no MIL/CEL

Thanks!

Fauvay, I had the same experience after cleaning my intake!

You have done a good deed for your engine and it is thanking you, maybe?

I can hear my turbo only in 1st gear with my window open - a distinct turbine whine that changes in pitch with RPM.

You could eliminate the serp. belt as the cause by disconnecting it (briefly, as you'll have no alternator) and running the same test.

Another possible sound source could be the idler roller or tensioner (Timing Belt system), but you'll want to eliminate the serp. belt first.

Yet another is a boost leak in the intercooler piping, which should show up as a gap between requested & delivered boost when looking at a VAG-COM/VCDS graph.