Hi 2003 T4 Transporter 2.5 @ 220,000kms here. I have developed a loud hissing noise in the cabin over the last couple of journeys which goes completely when I apply the brakes but returns once off the brakes? It sounds like a leaking air hose. No loss of braking effect or any obvious cause or leak....

Hi guys i noticed today for the 1st time that when i get on the throttle that my turbo starts making a real distinct hissing sound and that the car is way down on power , sounds to me like it has a boost leak somewhere . What are the main reasons that cause boost leaks also are there any easy fixes...

Hi All,

I have a mysterious hissing/suction sound coming from inside when accelerating in my T4 V6 Caravelle. It seems to be related to the Climate control because when it happens, the air flow cuts out.

It only ever happens on acceleration and it does not matter how small...