Turbo blow off valve

Viton

Well-known member
Is it possible to hear when the blow off valve is "Blowing-Off" on the 300Tdi ?
If so, what does it sound like? My engine is a stock LR repower kit, & the blow off valve has not been adjusted.

Here's my noise climbing a long grade.
My boost gauge is needle is right up against 15psi. I'm not floored on the accelerator, but if I push it a little more I can hear what I would say is the noise of a under-lubed bearing vibrating. It only take a small amount of throttle to hear this and I can start & stop the noise by pressing or backing off the throttle just slightly.

Thoughts.
 

AdamSanta85

Well-known member
There is no blow off valve on a diesel as there is no throttle body so it really isn't needed. Compressor surge is possible but on these small engines with small turbos (and low RPM which means less air flow) and no throttle body unlikely. I have never heard any surge running 16psi. The throttle peddling you are describing however could induce a surging effect as you are asking the engine for air (throttle down), then asking for less (throttle off), all the while the turbo is trying to react to your input but always lags behind what you are doing thus air backing up in the system causing some surging/noise

Can you take a video?
 

AdamSanta85

Well-known member
OK fine, are you OK with wastegate ?
Is the noise I'm describing, could it possibly be coming from the waste gate?

Sorry I didn't mean to come off arrogant, it's just that wastegates and blow off valves are different parts with different purposes.

Unlikely, when the wastegate opens up it just dumps more exhaust into the downpipe. Exhaust noise increases.

Does it sound like this? (fluttering noise)

<iframe width="560" height="315" src="https://www.youtube.com/embed/pKddHah07yw" frameborder="0" allowfullscreen></iframe>
 
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