w123 230ce overheating fan problem?

w123crazy

New Member
Joined
Apr 1, 2012
Messages
4
Reaction score
0
Location
uk
Your Mercedes
mercedes w123 230ce 1985
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=XQAG...DvjVQa1PpcFP7kLGFnGVCpRMtFHlbOAN6wl4N6rmzulA=


Thanks for your time
 

fr05ty

Active Member
Joined
Sep 25, 2011
Messages
40
Reaction score
0
Location
lincoln uk
Your Mercedes
450 slc
viscous coupling is shot...duct tape is a bodge but will do the job temporarily
 

busters the boy!

Senior Member
Joined
Mar 19, 2004
Messages
126
Reaction score
0
Location
Argyll & Bute
Your Mercedes
1989 W124 230e
How does one tell if the fan is electro-magnetic or viscous? Can you tell just by looking?

I have the same problem on my 124 (but mine is caused by temperature sensor not working, so not making the fan switch on).
 

lwbnick

Senior Member
Joined
Mar 4, 2010
Messages
1,288
Reaction score
0
Location
wales
Website
euromerc.tumblr.com
Your Mercedes
expedition
How does one tell if the fan is electro-magnetic or viscous? Can you tell just by looking?

I have the same problem on my 124 (but mine is caused by temperature sensor not working, so not making the fan switch on).

By the shape of it, viscous is aluminum finned, magnetic a smooth engarged pulley.

Generally 230E's be they 123 or 124 have magnetic fan clutches.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Yes electric fans have a pair of small wires going up to the front top of the head, the sensor is the front one with 2 connections, short these out and the fan should start if OK
 

star

Forum Supporter
Authorised Forum Supporter
Joined
Oct 6, 2004
Messages
6,209
Reaction score
1,874
Location
Reading
Your Mercedes
Smart + others :)
As above, 200/230's are electro magnetic, early switches have a single pole switch and later versions have 2 poles. If twin pole, bridge plug terminals to activate. If a single pole, bridge to earth to activate.
 
Last edited:

stwat

Senior Member
Joined
Jul 20, 2004
Messages
1,663
Reaction score
75
Age
51
Location
Sheffield
Your Mercedes
1989 300SE
Hi. I have replied to you on the other forum but I'l post my reply here too.

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.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Another snag is that rads can get blocked ion the centers, and many times this is the reason that the visco fans cannot cut in
 

stwat

Senior Member
Joined
Jul 20, 2004
Messages
1,663
Reaction score
75
Age
51
Location
Sheffield
Your Mercedes
1989 300SE
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.
6BF90670C074E46DC048E9DDDAC5D121.gif

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
FireShotScreenCapture004-W123230cefanproblem-YouTube-www_youtube_com_watch_vXQAGmxPY8LQ.png


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.
 
OP
W

w123crazy

New Member
Joined
Apr 1, 2012
Messages
4
Reaction score
0
Location
uk
Your Mercedes
mercedes w123 230ce 1985
  • Thread Starter
  • Thread starter
  • #11
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? :confused:

Thanks again.
 
OP
W

w123crazy

New Member
Joined
Apr 1, 2012
Messages
4
Reaction score
0
Location
uk
Your Mercedes
mercedes w123 230ce 1985
  • Thread Starter
  • Thread starter
  • #12
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
 
Top Bottom