A very loud problem--Fan??
 

Hey guys, when I start my R500 something under the hood(fan i think) becomes very loud(like a propeller plane taking off). This noise is very loud but goes away if i turn off the air(South Florida+summer=AIR CONDITIONING!! Is there anything i can do to fix it or should I take it to the MB dealer?:confused:

air pump
 

Are you sure its not the air pump, the air pump will be activated when the engine is started to warm up the cat.

Believe its normal with the A/C on in very hot weather. My ML500 and my E class does it also. Can't hear it though inside with the windows closed.

I have two 2-car garages on either side of house and i can hear it from my library on the other side of the house which is not a short walk:(

Thats normal with the aux fan on. Mine in both of my MB's are quite loud. In cooler weather when it does not come om its much quieter.

:zoom: Mine sounds like full engine run up on a aircraft just prior to take off. :rolleyes: Can't hear it much inside though. But outside:eek:

Jim

Very normal, MB wants as much air as possible passing over the a/c condensor at idle so that the a/c does not lose its cooling ability. As you pick up speed in the car the fan will slow down. I agree though, on my '06 E when outside of the car it sounds like a jet engine.

The cooling fan in my '06 C280 sounds more like a jet turbine. I agree that this is probably normal. I once had a VW Passat that did the same thing as does my wife's Volvo. I think it's a European thing.