w123 230ce overheating fan problem?

[jerkinamerk]

Hi there,

A big hello to everyone on this forum.

Ive got a 230ce 1985 w123, lovely beast but has been giving me some overheating problems since I bought it.

On the motorway she's fine, stays at around 80 degrees or under. However as soon as I'm in traffic she lets me down! almost hit 120degrees yesterday.

A few points

1. I opened the thermostat container to find there's no thermostat! So previous owner must have taken it out due to the overheating.

2. When I open the engine after long distant drives, there's coolant all over the air filter spewing out from the radiator cap I think.

3. I don't have another Fan to compare this to, but have a look at the youtube video, is this normal? The fan is barely rotating and I can even stop it with my hand. This was at 80degrees. I was thinking of duct Taping the fan to the main body which is rotating ,bad idea?

4. There's a switch which has fallen out from somewhere, again it's on the youtube video, any ideas what this is for? Should I tape it down?


http://www.youtube.com/watch?v=XQAGm...N6wl4N6rmzulA=


Thanks for your time

 

[stwat]

Hi, your video isn't working. Your fan has an electromagnetic clutch that should cut the fan in at around 95/100. It is controlled by a fan switch at the front of the engine next to the thermostat. 9 times out of 10 it is this switch that is at fault. The fan will spin freely and be easy to stop when the clutch isn't engaged.

An old and weak header tank cap will allow the engine to boil over at a much lower temp so replace that along with the thermostat and fan switch.

 

[jerkinamerk]

Cheers

Sorry about that, it's meant to be

W123 230ce fan problem - YouTube

 

[stwat]

Ah right. That switch is the thrust cut off switch and should be attached to the throttle linkage as shown in this pic. It's number 56.

When you fully lift off the accelerator the moving part of the linkage should click the switch to cut off the fuel supply.

Info taken from here. PARTSCATALOG.RU

The fan switch is the two pin connector behind the orange sensor in this pic

To test if your electromagnetic fan clutch is working, unplug the connector and bridge it together with a piece of wire or even a paper clip. Now switch on the ignition and you should hear the fan clutch clunk. It will now be locked.
If that happens all you need is a new fan switch. If not then you may have to test the wiring to see if you have a break somewhere.

 

[jerkinamerk]

Thanks to all for your help.

Got some time this weekend so decided to give it a go. Started with the fan because I think this is the reason the car is overheating. Or maybe wrong, how important is the fan? Is the connector a loose connector behind the 2 pin connection you mentioned?

Because I shorted the 2 pin connector which is on the main engine and no joy. the connector looked oiled up so I ended up cutting it, stripping the cables bare and shorting it and started the engine with no joy.

There is a loose connector which is just behind, sitting underneath the air filter. a black connector, there are again 2 wires being connected and the cable runs near the fan so not sure if this was what I was supposed to connect?

Thanks again.

 

[Will]

Starting with the basics - have you checked the fuse for the fan clutch?

 

[grober]

You need to also check that you are getting a 12v supply to the electromagnetic clutch. Check all your fuses carefully ---- depending on the age of the car and extra equipment --there may also be a relay involved in the supply side.

snap -Will!

 

[jerkinamerk]

FUSE!

Dhuh why not the simple things first!

Thanks I will be checking it later today. Any ideas to the black horizontal connector which is just behind the fan clutch. It's not attached to the engine, it's just a loose connector under the air filter?

Is a thermostat necessary? I know they're only a couple quid, but how important is it?
Without it the water runs anyway. I guess more important in winter?

 

[jerkinamerk]

Hi there,

Im still having a problem with the fan on my w123.

http://www.mbclub.co.uk/forums/attac...ing-switch.jpg

Had a look at this picture, can someone tell me what no3 is on this picture, still haven't managed to find out what it is.

I pulled the switch (position number 2). there's 2 cables in there, I've shorted it and the fan does not clutch. Someone mentioned they grounded this. How did you do this? as you have 2 cables?

Hope someone can help. oh btw i checked the fuse and replaced them all, so that rules that out.

hope someone can help

 

[grober]

You need to check the wiring that leads to actual electromagnetic clutch. Sounds as if it may have burnt out causing the overheating in traffic. Perhaps the previous owner erroneously blamed the thermo stat and removed it??

 

[jerkinamerk]

Cheers Grober,

Do you know what 1,2 & 3 are in the pic above?

 

[grober]

Have a look at the connections to the coupling.

 

[jerkinamerk]

aah, thanks alot grober

I just realised the link i had was broken!

http://www.mbclub.co.uk/forums/attachments/engine/22897d1301993450-w123-fan-clutch-overheating-switch.jpg

 

[jaymanek]

as far as remember, the single pole is for the temp display in the car, the double pole switch is the fan switch.. not sure about the connector..