Vw golf whistling sound?

Question

why as my vw golf mark 5 gt tdi got a whistling sound after the accelerator as been released coming from the engine? but it is far easier heard inside the car than at the engine?

Answer 1

whistling is normally a sign of a vacume leak check all your vacume pipes

Answer 2

the sound could be a intercooler leak as when accelerating high pressures are produced in the intercooler to cool the hot air.

The intercoolers are a common failure due to being mainly plastic.

Answer 3

Check out your air intake / vacuum hoses. also be aware that vw are b******s on dealer only parts from a cost point of view. Hoses are aproblem, as they are expanding and contracting with the heat of the engine at any given time.

Also, have the turbocharger gaskets/ seals checked out by a professional.... it may cost £30-70 to have them looked at, but could save you the price of a new turbo plus labour!

All this said, definitely a breathing problem.

Answer 4

Check the boost valve.

Answer 5

Could possibly be a slipping fanbelt.

Answer 6

could be vacuum seals or the turbo blow off has a leak near it. Also could be your fuel lines (most likely not but not unheard of!)  

Answer 7

Maybe it's happy about having the accelerator released.