Can anyone tell me what the hunning noise is that comes from under the bonnet when you switch off your engine ..it normally runs for about 25 seconds
or is it just my spooky van
ps its a 07 plate t28
I was lead to believe that the noise is a pump which circulates water around the engine and also part of the turbo to prevent the oil in the potentially red hot turbo from burning or damaging the turbo bearings ( a problem on a lot of early turbo cars ).
Some of the highly tuned Jap turbo cars have auto engine run on's to do the same job..
So Its the water pup cooling the turbo and its ok to leave or is it the turbo valve sticking they are both feasible and if its the valve does anyone know how much they cost to fix
just like to say feedback has been excellent from everyone and great to know mine isnt the only one doing it cheers everyone*<>
This valve is responsible for controlling the movement of the pneumatic actuator which drives the wastegate. The wastegate is an internal valve in the turbo-charger which controls the amount of exhaust gas that flows over the turbo impeller generating boost. Under normal operating conditions the engine's ECU sends signals to the N75 valve asking it to open or close which adds or reduces pressure on the wastegate actuator which results in more or less boost. The question is, is the valve faulty or is it receiving a signal from the ECU when it shouldn't. Either way, I can't see it doing any damage, especially when the engine isn't running. I would try and get it on VAGCOM to see what fault codes it throws.