benz_addict

My V12TT developed a whining sound coming from the left (driver's) side of the engine. It happens ONLY after letting go of the accelerator and whines down the the engine RPM's. If I floor it the whine goes away completely.

I am also having a boost problem. It doesn't feel as fast as it used to be.

Here is the video of the sound:

Can it be the diverter air valves?

xabo

"This video does not exist"

benz_addict

LINK fixed

xabo

What was the problem?

kamilclk430

I think he meant that he fixed the video to show up.

That is a weird problem you sure its not coming from the rear end?

xabo

Okay….thanks

benz_addict

I mean I fixed the link to the video.
Problem still persists. DEF from the front driver side
I did change the deceleration divert valve with new spring but no changes, no vacuum leaks either and no pinching lines. Whining is still there. I'm wondering if it could be the ABC pump, but why does it only whine if I build boost then let off the throttle?

alx

Belt or pulley bearing. Or water pump or alternator. Something rpm related.

Or gears. Check tranny for metal particles/ dust.

benz_addict

Boost fixed, new pump and proper bled.
Noise fixed, was the ABC pump.
Thanks for the help!

Dr Matt

So what fixed the low boost problem?

Ekselent

You mean a new circulation IC pump?

radride

His IC pump crapped the bed.

R.K.

JRockey

My '08 is making a whining noise at 2500 rpm. It happens in neutral so that eliminates the driveline. It is more pronounced on deceleration like the OP but it is downright irritating to drive on the hwy at 75 mph. I had it at the dealer yesterday for an unrelated problem that they couldn't fix so I had them take a listen to the whining. Their recommendation - "keep driving it". That's right - they know there is a whining and its irritating as hell but want me to keep driving it. I think I will just take it to another dealer