Faulty Viscous Fan??

[nismo786]

Hi again,

The viscous fan in my Mercedes CLk 320 runs very fast all the time, and while doing a carrot test, when car was switched of i turned the fan by hand and it turned very easily and freely.

Does this mean that it is faulty?, if so what is the best procedure to take it out and replace it, do i need to buy the entire fan or just the coupling.

Please, your advise will be much appreciated.

Regards

QC

 

[television]

Not to clear here, you did the carrot test with engine at 85 c + did it chop the carrot or stop.

Yes the fan is easy to turn with the engine off, thats normal, and yes it turns all of the time when the engine is running, thats normal.

Did it chop the carrot ??????

Malcolm

 

[nismo786]

Hi

Yes carrot was chopped off easily, but fans runs very fast even when i start the engine cold, it starts immediatly and runs very fast and loud like it is going to take off!.

Any ideas??

Cheers

QC

 

[television]

Its normal,dont worry about it,yes they are noisy, if it turns when engine is off,its OK.

malcolm

 

[Hibbo]

If you are convinced it is knacked, do the carrot test with the engine cold. It should stop the fan.

 

[nismo786]

How to remove

Hi

Another question, is the viscous fan normally belt driven as mine is not belt driven, but has electric switch on top of it next to radiator.

Even if i turn the ignition to on (without starting the car) the fan comes on loud and quick.

How do i take the fan off without removing the radiator?.

Thanks for your help on this.

Cheers

QC

 

[Ultymate]

Here is a picture of your fan http://www.detali.ru/cat/oem_mb2.as...GA=722.618&CT=M&cat=19Y&SID=20&SGR=030&SGN=02 it will be situated behind your radiator and is deffinately belt driven the viscous unit that fails is item No.5 I think the electric fan you're looking at is the air-con fan which sits right in front of the radiator and if it runs as soon as you switch on your ignition has a fault.

P.S. If your car has a fan behind the rad ie between the rad and engine then it may have been modified
Heres another picture http://www.detali.ru/cat/oem_mb2.as...GA=722.607&CT=F&cat=45Y&SID=50&SGR=015&SGN=01 by the looks of it there maybe an option of one or two electric fans for the air-con but either way the engine cooling fan is still a viscous coupled belt driven one

 

[television]

OK I am with you now, there are 2 types of fan fitted, your is not the viscous fan but the electic clutch coupled fan, as you say one of the wires goes to the front water temperture sensor. Take the wire off the top of the sensor and the fan should stop. This wire grounds the - wire and completes the circuit. If the fan stops with the wire off,it is the sensor at fault, it it continues to run it will be a internal short within the fan unit.


Malcolm

 

[Ultymate]

Morning Malcolm so the large single electric fan has a viscous coupling? I live and learn I've not come across that previously.

 

[television]

Morning Malcolm so the large single electric fan has a viscous coupling? I live and learn I've not come across that previously.

Hello, there are two types of fan,they both look the same from the outside,but if you look close on one of them,there are two wires comming out of the top, one wire goes too the + feed, and the other is grounded when the sensor drops to Zero Ω . this way the fan can run on when the engine is off and hot.

We had some threads on this last year, but as sods law cant find one, will find one on computer 3 tonight.

malcolm

 

[nismo786]

Thank you Malcom

Mine is this one:

http://www.detali.ru/cat/oem_mb2.asp...SGR=015&SGN=01

Is the temp sensitive switch on the radiator or next to the water pump, when i disconnected the wire next to water pump, fan goes off and comes on when i reconnect it.

Thanks to you guys i am becomming a sort a mechanic when it come to my car.


Cheers

QC

 

[C220GJS]

This thread sounds similar to your problem;http://forums.mercedesclub.org.uk/showthread.php?t=24161.

 

[television]

Ooooooops must be getting old, I know that we dealt with one, alas only two weeks back, I thought it was last year. when the first one came up I thought ahha thats a water problem and it did nlt reggister on this one,maybe it was the way it started off.

The little sweet shop come post office gets ever nearer. thank you C220GJS
Malcolm