FR TDI with slight fog horn tendencies

[Greytop]

I have noticed over that last couple of weeks that my FR has started to make a slight but noticeable 'fog horn' noise (only way I could describe it ) when lifting off the throttle, its more noticeable when sat on the drive at tick-over or reversing into a parking space. Anybody else noticed this with their FR TDI or TDI

 

[MartH]

Yep mine starting doing it a couple of weeks ago. Its the N75 valve apparently, parts now in stock just got to book it in...Most noticable in slow moving traffic or just revving engine.

 

[Greytop]

Yep mine starting doing it a couple of weeks ago. Its the N75 valve apparently, parts now in stock just got to book it in...Most noticable in slow moving traffic or just revving engine.

Hi MartH, yes mine does exactly as you described....... an N75 valve, umm do you know what it does? Some kind of pop off valve on the turbo or something? Did your dealer diagnose it quickly?

 

[MartH]

Car was in for air bag switch, which is all sorted. Told them about the noise and they got the mechanic to come out and have a listen. Half an hour later switch replaced and noise diagnosed. Definately something to do with the turbo, but not too sure, is it the waste gate actuator?? Didn't have it in stock so they had to order it, it's in now so just got to book it in...

 

[richpaul]

Its the turbo vaccum solenoid. It vibrates when faulty. It controls the actuator to open and close the waste gate on the turbo. Mine has made this noise from only 6 miles on the clock, it now has 10k on it and its gettinig replaced on the 21st march. Nothing to worry about, just annoying.