https.ylli

hello to all… i’ve come here to ask about turbo noise on the om642 engine (Gl350.) I just want to confirm if this is normal or not… When in park, and giving it some revs, it sounds like the compressor of the turbo surging when i let off the throttle after giving it some gas… but when i do it again, it sounds like a blowoff valve… just releasing the pressure into the atmosphere, and won’t do compressor surge again… I notice the compressor surge alottt when driving low speeds and building boost for like 5 seconds, then letting off. To me, I don’t like the sound… I know it’s normal for some turbo cars, as i know why it does it, and how it works… but i bothers me sometimes because…
Questions:
1. Is the compressor surge normal on these…
2. What is the reason for it to sometimes surge, or blow off
3. And do these even have Blow Off Valves?

Ive attached a video of someone recreating the compressor surge sound when in parked. I can never get it to do it on camera. This is not my video and the credits go to wherever and whoever i got this from…

General Disturb

Hi, yeah I would check your turbo actuator. Little black box attached to turbo. It controls the waste gate which doesn't seem to be working in this video. Fairly easy fix, just replace it.
Cheers

https.ylli

Thanks for the reply. To be honest, i did think it was that, but that’s weird. I don’t think it causes damage, but i wonder… do you need to calibrate them? We had to replace the turbo and we got a junkyard turbo, good shape just had no actuator. We exchanged our actuator to the used turbo, and since then we have been hearing it wayy often

General Disturb

Sorry been busy, did not calibrate mine, don't think it's necessary or possible. I just bought a cheap one from China, works fine.

Don't think it does damage, the noise is from the air breaking the sound barrier as if forces its way backwards out around the turbine blading as it has nowhere to go IIRC.

Sallad

Personally, I think it sounds cool. Like a rally car or something (turbo flutter)

But how would a bad wastegate cause this sound? Sounds like the excess boost isn't venting properly. I'd look in that direction.