Phaeton/Spartin Unusual Wooshing Noise at Idle

[phishphair]

I have been though three visits to the shop that began with a coolant leak, then an oil pressure warning (sensor bad) then a coolant leak into the intercooler. What a last few months. Thank goodness for extended warranties.

My question in now that it appears to be running ok, at Idle I am getting a loud wooshing noise when at idle, I never heard it before all the problems. Any ideas?

[Skip426]

Questions .
Year of coach ? Cummins ? ISB , ISC?
Side or rear radiator?
Coolant leak into the inter-cooler , is a real puzzle , most turbo diesel inter-coolers are air-to-air coolers not air-to-water. Do you have copies of the invoice saying what part was replaced?
If the coach radiator was replaced then there is a chance that it came with new ( or different ) rad fan control sensors , and the noise your hearing is the rad cooling fan , on at idle when it was not on before.