Temp Gauge W124

[jon_viola]

Hi, could anyone tell me the "normal" position for the temp gauge in traffic around this time of year. Should it stay in one place or does it vary? My fan seems to stay at the same speed no matter what is this right?

Cheers
Jon

ps its a 300-24 ce

 

[jaymanek]

Your fan is viscous i would think...

You would expect temperature to rise up to close to 100 in stationary traffic when its hot, this would drop t 80-90 as soon as you pickup some speed...

 

[Ian B Walker]

Your fan kicks in at 94-104 degrees according to the documentation I have

 

[janner]

Under normal driving it should stay at whatever temperature your thermostat is, probably 87 degrees.

 

[jon_viola]

Thanks for all this, it does as you say stay around 85ish in normal driving but yesterday it went above the halfway line in traffic and that worried me as on my previous W123 280ce the needle didn't ever move...

 

[grober]

Do the"carrot test" to check your viscous fan is cutting in OK. If the temp gauge going no higher than 50% deflection in heavy traffic you probably dont have anything to worry about. Remember if you have aircon there are one/two electric fans in front of the radiator to check also.

 

[jon_viola]

The "carrot test"? Can you explain!
Thanks

 

[grober]

carrot test

The "carrot test"? Can you explain!
Thanks

see this post http://mbclub.co.uk/forums/showthread.php?t=35892&highlight=carrot+test
and others just put carrot test into the search box.

The fan will free wheel when its cold and give the impression its being driven-its not. when it reaches its cut in temperature the viscous coupling engages and the fan is then driven- [tends to run faster and louder]. to check whether its free wheeling or being driven you try to stop it by impeding the blades with an object. something soft or pliable which wont damage the fan but provide enough resistance to stop it rotating if its freewheeling. If the clutch is engaged it will hit the object with force and break it. hence the carrot which is ideal. then check your engine temperature to see when the fan cuts in.

 

[janner]

Alternative carrot test.
Pop a sliced carrot in the radiator header tank.
Drive for 10 minutes.
If carrots are Al Dente then radiator too cool.
If carrots disappear and are replaced with carrot soup then radiator too hot.








NO, don't try it

 

[Ade B]

I was wondering about this recently - my CE gets up to 110 when crawling along a queue with the AC on - between 80-90 for normal driving around 100 London stop start.

Tried carrot test and the viscous fan seems fine, not sure if the secondary (AC) fan is working as typically last time I tested it stationary it didn't get over 100... as I havn't had chance to poke about enough in the last week..

Am going to change the coolant this weekend and see if that makes a difference.

Ade

 

[andy_k]

that sounds right, I think the fans switch on at about 105, in heavy traffic you'll see the temperature going up and down quite a lot

Andy