turbocharger vacuum modulator has a buzz in it. Does that mean it is going bad and needs replaced? I get a code that says i have low boost and the check engine light is on. It seems to be running fine.

My son's buzzed for a while and then quit. If it continues you may need to replace the solenoid. Also see if the dangling filter is dirty.

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Low boost could be a problem with the vacuum solenoid to stuck vanes in the turbo.
Replace the buzzing solenoid and check that the vacuum actuator lever on the turbo moves.
At idle, vacuum to the turbo actuator should be high. Disconnect the vacuum line and watch the lever drop. Re connect the vacuum line and the lever should pull up again.

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U.S. Army Retired

ok

I think it's excessive carbon buildup around the exhaust side of the turbo.

When was the last time you did a WOT?

Performing a wide open throttle (WOT) while the engine is at optimal operating temperature. got rid of the code.

Open her up on the highway for 5 minutes or more when the engine is Hot. Burns off the stuck on carbon that is preventing the vanes from spinning, which in turn will set off an engine code.

I had the same noise and besides performing the (WOT), ...... an engine flush with an oil change got rid of it.

Before performing the WOT, check the turbo for shaft play. If the turbo has excessive shaft play then the turbo is on its way out and needs replacement.

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2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster"
2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket"
1982 Fiat 124 Spider Convertible. "Fiona"

You can also fill the exhaust side of the turbo with foaming oven cleaner, wait ten minutes I think, and that can help. Don't do the WOT if the turbo shaft has a bunch of play in it. It should have "barely perceivable" play that you can barely feel with your fingers. When you feel 1/16" or so of play, it's past it's prime, and I would avoid high boost, high RPM's.

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