[foundyouoverhere]

I have a 2005 C230. About 30 secs after it starts until about 30 secs after it is turned off it sounds like a jet engine is in there.

It doesn't matter if it is cold or warm when it starts, or if the a/c is on or off. I have located the problem, which is the radiator fan. I have gone through the forums and tried a few things offered. The things I have tried are as follows:

reset the a/c by pushing the defrost and recirc air buttons until the led light quits blinking

moved the fan itself to see if it was stuck, which it wasn't, it turned easily

jiggled the fan back and forth to see if it was loose, it was on correctly

tapped the relay with a screwdriver while the car was running to see if it would adjust, didn't work

changed out the fuse, still didn't change anything

I amabout to pull out my hair, please help

 

[ryanmoney]

I have a 2007 c230 that would do the same thing but it also stopped running all together a couple times and caused the engine to start overheating. It ended up being a faulty fan assembly. The fan and fan module are sold as one unit and when the module fails you have to buy the fan assembly. There is no relay for the fan, it is contrlled by the cars electronics feeding information to the fan module. So you will need to have it checked to verify if the fan is actually the cause.

 

[Ryker13]

After mine sat for about two days, I have Indi's same problem.

VERY loud, I wondered what people were looking at, so I turned down the radio and it truly sounds like a jet.

 

[rudeney]

The new fans used on the M272 and M273 engines can be very loud. The one on my CLK sounds like a civil defense siren when it winds up. The control is smart - when the A/C system demands max cold, it will run the fan at full speed. It also runs at full speed when engine temp begins to climb and ambient temp is high. For example, in cooler ambient temps, my engine temp can climb above 90C and the fan just barely runs, but when it's 90F outside, the fan comes on full blast when the engine temp edges over 85C.

 

[Ryker13]

Sounds like mine is normal then!

It was our first 95-100 day around here and it had been sitting in the parking lot all day at the hospital.

 

[Mpho]

My mercedes C320 engine cooling fan runs immediately when the engine starts,what are the cause?

 

[rudeney]

This means that it is not getting a signal from the ECU. If the engine starts and runs normally, then it could be a bad temperature sensor, a bad fan control unit (built into the fan) or a wiring issue. You need to get a proper diagnosis bu pulling codes.

 

[C230ISTHEBEST]

I recently experienced the same issue with the radiator fan for my 2006 C230 as it was going full speed when the key was in the ignition alongside the engine being on as well. This occurred after seeing I had stretched my serpentine belt while driving and caused the alternator, power steering pump and all the other components the belt is in charge of from functioning in the moments of the drive. I replaced the belt within the the same hour of the old belt tearing and when I turned on the engine to see the belt run , I also heard the jet noise of a sound the radiator fan can make ! I simply unplugged the fan and drove the car in two different intervals of the day for 5 minutes each. The next morning , I plugged the radiator fan back in and everything was back to normal as I figured the computer would know what to do this time !

 

[rudeney]

It could also be bad temp sensor:

https://benzbits.com/M272/CoolantTempSensor.pdf