Engine fan at maximum speed all the time
Thread Starter
Newbie
Joined: Apr 2015
Posts: 5
Likes: 0
2003 C180 Kompressor
Engine fan at maximum speed all the time
Hi all,
I have a 2003 C180K w203 and from the second you turn the ignition the fan speeds up to the maximum speed and stays there. The temperature on the screen is working properly and all appears normal. It's so loud that for smaller trips i just unplug the fan so i don't have to hear the noise since the temperatures remain at around 80c which is normal. This has been the case for roughly 2 years and for some time before that the A/C would only blow warm air even when turned to the coolest setting. I'm not sure whether that is related to the fan problem but help on what this could be would be greatly appreciated.
Thanks
I have a 2003 C180K w203 and from the second you turn the ignition the fan speeds up to the maximum speed and stays there. The temperature on the screen is working properly and all appears normal. It's so loud that for smaller trips i just unplug the fan so i don't have to hear the noise since the temperatures remain at around 80c which is normal. This has been the case for roughly 2 years and for some time before that the A/C would only blow warm air even when turned to the coolest setting. I'm not sure whether that is related to the fan problem but help on what this could be would be greatly appreciated.
Thanks
Super Member
Joined: Oct 2013
Posts: 527
Likes: 20
From: Carolinas
2005 C230K SS
Good place to start is the coolant temp sensor...cheap to replace. When the signal from the ECT is unreliable or not present, the car assumes a worst case scenario, ie an overheat condition, and the fan runs full speed.
Also, get a obd scanner and look at the live data and see what the coolant temp sensor value is...when it's failed it will fluctuate or show a value of -40.
Other than that find an indy with DAS
Also, get a obd scanner and look at the live data and see what the coolant temp sensor value is...when it's failed it will fluctuate or show a value of -40.
Other than that find an indy with DAS
Last edited by RWDlifer; Apr 25, 2015 at 11:05 AM.
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
I concur with RWDlifer, start with coolant temperature sensor - it's like a $15-20 OEM part.
It be helpful to know the mileage & location of car. Also, sedan or coupe.
It be helpful to know the mileage & location of car. Also, sedan or coupe.
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
Unplugging the fan just to avoid hearing the noise for 2 years is NOT a good idea. During those 2 years, you likely been driving on the highway in the hot summer countless times,... where you need the front radiator fan to kick in to prevent damage to the engine.
If you have a crying baby, you don't tape the baby's mouth just because you don't want to hear the noise,... you need to find out why the baby is crying,... hungry, bored, in pain, sick, uncomfortable, need diaper change, etc,... and take care of the cause. Not just eliminate a problematic symptom. Yes, most of us here, baby our cars,... so this is a fair analogy.
If you have a crying baby, you don't tape the baby's mouth just because you don't want to hear the noise,... you need to find out why the baby is crying,... hungry, bored, in pain, sick, uncomfortable, need diaper change, etc,... and take care of the cause. Not just eliminate a problematic symptom. Yes, most of us here, baby our cars,... so this is a fair analogy.
