I think I have narrowed this noise down to the downpipe/puck

[TType85]

From my thread on the regular tech sub forum:

I have narrowed it down to the downpipe/puck. It seems to happen when cold only. I start the car with the WG rod connected, kill the motor and get that sound. Disconnect the WG rod, no sound. Kill the engine, pop the rod off while it's making the noise and the sound stops right away.

WTF could make that sound? The puck looked good, the turbo looked like it had a decent sealing area around the puck.

 

[Pronto]

Boost actuator bad?

 

[TType85]

Boost actuator bad?

The actuator has plenty of tension on the puck and I disconnected the vac hose to it to see if was something in the actuator. What else can go bad with it?

 

[Pronto]

Borrow an actuator and see what happens.

 

[TType85]

Borrow an actuator and see what happens.

Will do that tonight. I think I have one in my "box-o-buick-crap".

 

[TurboBuRick]

Hmm, that's weird. How do you have the boost line to the actuator hooked up?

RL

 

[TType85]

Hmm, that's weird. How do you have the boost line to the actuator hooked up?

RL

Right now, I have the line disconnected. In the video I have an RJC boost controller hooked up so it is from the turbo fitting to the controller then to the actuator. The line right now goes from the turbo fitting to the boost controller then is capped off.

When it is making the sound you can feel the vibration through the turbo housing. I have had it apart and both the cold and hot side are perfect, no shaft play. You can also hear the turbo still spinning before and after that sound.

 

[TType85]

Ok, tried more tonight. It is not the actuator. I can feel the vibration in the turbo when it is happening. What would cause a DBB turbo to do this? I probably should call PTE tomorrow...

 

[Phoneguy]

Do you have good oil pressure at the turbo?

Bryan

 

[TType85]

70+psi cold. I have a TR Custom Filter/Turbo Saver. I know it's getting oil; when I primed the pump I forgot to hook the line up and made a mess.

 

[Phoneguy]

Is the drain hose kinked?

Bryan

 

[Phoneguy]

What oil are you using?

Bryan

 

[TType85]

What oil are you using?

Bryan

Stock drain, actually on my 2nd one, the first kept leaking. Oil is VR1 20-50. New cover/pump from TA performance.

 

[Phoneguy]

Is there a restrictor in the turbo? Sounds like too much pressure while cold. Try 1040 oil.

Bryan

 

[TType85]

The restictor is there, -4 an line too. I will change the oil. (ack 8 more quarts since I have a deep pan)

 

[Phoneguy]

Remove the restrictor and fire it up cold, I bet the noise goes away.

Bryan

 

[TType85]

Remove the restrictor and fire it up cold, I bet the noise goes away.

Bryan

Is it safe to remove the restrictor?

 

[Phoneguy]

Not suggested. Some run without it. Im just saying to remove for testing instead of dropping the oil. Someone will chime in about the restrictor with more knowledge than I have...

Bryan

 

[Pronto]

Sounds like the ball bearings are failing.

 

[TType85]

Sounds like the ball bearings are failing.

What would cause a failure after under 500 miles? It was always fed clean oil.