C180 Overheating

[Arkonite]

My first Merc is a 1997 C180, had it about a week now and in general all is well with it, it's been a bit neglected previously and i have fixed a small number of minor faults.
I have covered about 500 miles in it and it cruises up the motorway just fine, temp gauge sits about 80 or just under/over, engine has not so much as missed a beat and runs like a well oiled clock. However once you get into the city centre the temp slowly rises. Car has air conditioning fitted as a factory fitted extra [its a basic 180 other than this] so the engine has an electric fan only and no viscous fan. I have ordered a new thermostat anyway as replacing it would do no harm.This evening i managed to pull out of the traffic [no mean feat in the centre of edinburgh trapped inside all the tramworks cones] and have discovered that the electric fan is not working when the temp warning light is on and the temp has risen to just below the 100 mark. Anyway could anyone help and give me a bit advice on how to and what to check and investigate to determine if it is the fan itself or a relay.
Any clues as to the most likely suspect ? and how i would go about checking

 

[Alex Crow]

have discovered that the electric fan is not working when the temp warning light is on and the temp has risen to just below the 100 mark.

which temp warning light is this then! please explain.

coolant just below 100 deg is absolutely fine, no need to worry at that temp at all.

 

[television]

Electric fans do not cut in below 100c

 

[Arkonite]

water temp warning light on instrument panel, one with the little radiator on it, it is slightly bothering as the coolant for the fridge will not be cooled in stationary traffic and this is noticable. At some point the fault needs fixed and i agree its not something to worry to much about, but any help in identifying why the fan does not operate would be greatly appreciated.

 

[Alex Crow]

that is the coolant level warning, not temp.

if there is an aircon fault stopping it refrigeration working, then the fan will only be triggered by engine temp. as mike TV says the fan will not run below 100 deg anyway.

worry about it when it is at 110 deg and still not running.

 

[Arkonite]

coolant to high perhaps

sorry i missed the last post on this.

would the coolant level warning light come on if the coolant level is to high?

Car is fine and runs at almost 80 degrees or just above, 99% of the time, i have noticed that the expansion tank is virtually full, so with the expansion of the coolant as it reaches a certain temp when stuck in traffic cue's [which is when the light illuminates] would it therefore follow that it triggers the warning light. ie to much coolant in the system?

 

[television]

The expansion tank will fill up with the engine hot, so that is normal,,there is no light to tell you that it is too full,,only maybe if it is too low.

How many fans do you have

 

[Arkonite]

i have aircon so only an electric fan, there is no viscous van, and i hate carrots.
As prev mentioned, temp sits fine for all driving, and hovers just above and just below 80 depending and i am quite happy with that, its just urban driving, keeping the interior fan on with aircon off keeps the temp down and light stays of.
I dont think this is a real major prob or something to greatly worry about but its one of those nippy little things that you just want to sort. Antifreeze/coolant level is high, expansion tank full to the brim nearly [to high] coolant mixture is 50%, no engine missfires, engine leaks, gasket leaks and motor does run like a proverbial watch, after having car for a bout a month, i withdraw my previous statement that i thought the car had been neglected, it has not, there are to many signs of regular maintinance, but i do think it has sat around unused for quite a few months.

Its not the greatest thing sitting in a que of traffic getting roasted alive cos your interior fan is on cooling the engine just to keep the idiot light of.

As always any pointers to a poss solution would be greatly appreciated.

 

[turbopete]

as far as im aware, ALL MB's have a viscous fan, engine side of the radiator, and an electric fan, sometimes 2, at the front side of the radiator. if your car has no viscous fan, perhaps this could be your problem?

 

[television]

as far as im aware, ALL MB's have a viscous fan, engine side of the radiator, and an electric fan, sometimes 2, at the front side of the radiator. if your car has no viscous fan, perhaps this could be your problem?

The 111 does have an engine fan in most cases

http://www.detali.ru/cat/oem_mb2.as....418&VIN=*&CT=M&cat=19K&SID=20&SGR=030&SGN=02

If you only have an electric one in the rad then this will not come on till over 100c

What are the first 6 Vin numbers, or after 202 what are the next 3

 

[Arkonite]

numbers

first 6 numbers are 202018

 

[Alex Crow]

so your only problem is the level warning light.

the sensors in the header tank do fail, could cause the light to go on when hot.

as said before, temp at 100deg in traffic is correct.

 

[Arkonite]

thanks very much for yor help, i agree i dont think its actually overheating because the temp gauge never really goes up by more than a certain point, if it was overheating it would keep rising, always supposing the temp gauge is not faulty. It's just something to keep my eye on. Also time to go on the hunt for a c180 owners manual so i can work out what all the idiot lights are.

once again thanks