i occasionally get a wierd hissing sound out of the turbo when no boost so checked it out and noticed a small chunk taken out of the front of the compressor wheel right next to the nut. im thinking that the sound is that when no boost the wheel slows to where airflow is messed up? what do yall think? should i replace the wheel?

 

Anything that spins at 100,000 plus rpm and has a chunk taken out of it is going to wobble badly.
Seems to me you would have more problems than you describe.

 

how hard is it to replace the compressor wheel? is it straight forward or a little more involved than i think?

 

ok but if it was a chunk where is it? i dont think the wheels are that hard to change i know a few here have done it im sure they will chime in.

 

its right up against the nut that holds the wheel on the shaft. its small. i would take a pic of it, but i killed the camera awhile back and haven gotten a new one yet

 

From what you describe, it sounds like the chunk they remove when balancing the wheel. There is another recent thread about this very same chunk with some great closeup pic detail...I just can't seem to find it to refer you! :-) Anyways, check the other forums, the thread was something like 'HTT compressor wheel' and see if it has the very same chunk missing next to the nut yours has, ok? <Here it is: https://www.dieseltruckresource.com/...d.php?t=159168 > Click on the pics to enlarge and compare. If yours doesn't look as nice and neat as the other, you may have a different problem, no? And BTW, exactly what condition are you describing when you say hissing with no boost? Do you mean when you shut off the motor, there is a hissing as the turbo spins down? That would be pretty normal I think. Good luck to you!

 

thanks for the info 92Dually what im discribing is at the same location as those pics. is it normal? i never took notice of it before. and the hissing sound is when your foot is off the go pedal and there is no boost. but it only happened 2 different times in last 4 days.

 

Gotcha! Those really are great pics in the other post, huh? I do believe those missing chunks are normal for balancing...I'm just guessing here(not being expert in turbo's at all), but the hissing you refer to could just be pent-up pressure with the closed throttle sort of 'seeping past' the wheel at speed(but no throttle), or could be a leaking intercooler boot or even gasket somewhere. Next thing I'd check if it recently appeared is all the clamps tight and visually/feel check all around the boots for a possible split/leak. Sorry, that's about the limit of my turbo knowledge!! Good luck!

 

The 'chunk' is from balancing the compressor wheel either from Holset, or a rebuilder if it's been rebuilt. No worry there, it's normal on all turbos.

As for the hissing sound, make sure you don't have any boost leaks at the intercooler piping, intake, air filter/inlet tube, line to boost gauge, etc. Also make sure that the compressor housing on the turbocharger is tight and that the clamp holding it is secure and snug.