Hey Guys,

I have a 2010 W204 C3004M. Starting a few weeks ago the engine coolant gauge would display "unstable" temperature readings.

For example, once the car was fully warmed up to around ~90C

The following would happen:

1. Sometimes the temperature reading would drop to around 80
2. Sometimes it would go back up to around ~90C

This would happen multiple times during one single trip.

It NEVER goes above 90s though.

Anyone experiencing the same problem? Should I bring it to a service center?

Thanks!

 

Same exact thing happened to my 2010 E class. Except the temperature would sometimes go higher than 90!!! (scary, I know!) I brought the car into the dealer and they performed what they called an "ECU update" and after that, my temps stabilized.

I would just bring it into them

 

mine is around 80 - 90 also not too bad I dont think anythings wrong

 

can anyone help me figure out why is it that some c class have an extra part that attaches to the coolant tank. looks like a round plastic holder

 

How have you solved the problem?
This thing has happened to me a few days ago.
Coolant warning light come "ON" and "OFF", but the light is not always "On" and "Off". It might be ON today and disappear after a few min.. It may happen tomorrow again for 10 min. or so or may happen after a few days.
When the warning light is "ON", the coolant temperature is unstable, going lower than 80 sometimes or going higher than 100.

I brought my car in, but the diagnosis has not been completed.
They initially said the software update might resolve the problem when I dropped it off, but they just informed me that mine has the latest software and there is no software to update..