ML63 Normal Operating Temperature
Thread Starter
Newbie
Joined: Feb 2024
Posts: 7
Likes: 2
2011 ML63
ML63 Normal Operating Temperature
HI, I have been driving 2011 ML63 for 6 years now and the temperature was always, essentially, constant 95 celsius. Never when up by 2 or down by 2. Over the past 6 months I noticed the temperature would slowly decrease so that driving in Miami in 90 degree (fahrenheit) the coolant temp would be 92 celcius for example. Turns out the thermostat was failing in the open position. I just had a new one put in and now when I drive the temp gauge is all over the place. It can now range from 85-120 celsius.
Today for example I was at a traffic light and the coolant temp hit 120 and then started to slowly decrease to 95. Another time I entered the freeway and the coolant temp dropped to 85.
The shop says this is normal for the M156, I checked the manual and that is correct. I, however, have never seen my gauge move like this while driving the car.
Can some other owners let me know your experiences, I pamper this car, its my daily driver and don't want to damage the engine obviously.
In the end I suppose I am looking for some reassurance and wonder why the gauge never acted in this manner for previous 6 years of ownership.
thanks in advance
Today for example I was at a traffic light and the coolant temp hit 120 and then started to slowly decrease to 95. Another time I entered the freeway and the coolant temp dropped to 85.
The shop says this is normal for the M156, I checked the manual and that is correct. I, however, have never seen my gauge move like this while driving the car.
Can some other owners let me know your experiences, I pamper this car, its my daily driver and don't want to damage the engine obviously.
In the end I suppose I am looking for some reassurance and wonder why the gauge never acted in this manner for previous 6 years of ownership.
thanks in advance
Senior Member
Joined: Oct 2023
Posts: 461
Likes: 235
From: Massachusetts
ML 63 AMG
Originally Posted by ML63 driver;[url=tel:8931988
8931988[/url]]HI, I have been driving 2011 ML63 for 6 years now and the temperature was always, essentially, constant 95 celsius. Never when up by 2 or down by 2. Over the past 6 months I noticed the temperature would slowly decrease so that driving in Miami in 90 degree (fahrenheit) the coolant temp would be 92 celcius for example. Turns out the thermostat was failing in the open position. I just had a new one put in and now when I drive the temp gauge is all over the place. It can now range from 85-120 celsius.
Today for example I was at a traffic light and the coolant temp hit 120 and then started to slowly decrease to 95. Another time I entered the freeway and the coolant temp dropped to 85.
The shop says this is normal for the M156, I checked the manual and that is correct. I, however, have never seen my gauge move like this while driving the car.
Can some other owners let me know your experiences, I pamper this car, its my daily driver and don't want to damage the engine obviously.
In the end I suppose I am looking for some reassurance and wonder why the gauge never acted in this manner for previous 6 years of ownership.
thanks in advance
Today for example I was at a traffic light and the coolant temp hit 120 and then started to slowly decrease to 95. Another time I entered the freeway and the coolant temp dropped to 85.
The shop says this is normal for the M156, I checked the manual and that is correct. I, however, have never seen my gauge move like this while driving the car.
Can some other owners let me know your experiences, I pamper this car, its my daily driver and don't want to damage the engine obviously.
In the end I suppose I am looking for some reassurance and wonder why the gauge never acted in this manner for previous 6 years of ownership.
thanks in advance
MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,084
Likes: 440
From: Melbourne, Australia
2010 ML550 VIN WDC1641722A564750, 2010 B180
Unfortunately, new parts arent a guarantee that they work. You don't want your temp at 120 (assuming its accurate) more for the tranmission than the engine.
There's a few posts in this forum that suggest the temp guage is "managed" by the ECU and that's why they don't vary much even in extreme conditions.
What brand was the thermostat? It might be worth testing the temperature sender unit as well. These cars are getting older and its possible that you've annoyed the temp sender unit when swapping the thermostat. Sorry it's not a definitive answer to your problem, but at least a few clues on what to consider.
There's a few posts in this forum that suggest the temp guage is "managed" by the ECU and that's why they don't vary much even in extreme conditions.
What brand was the thermostat? It might be worth testing the temperature sender unit as well. These cars are getting older and its possible that you've annoyed the temp sender unit when swapping the thermostat. Sorry it's not a definitive answer to your problem, but at least a few clues on what to consider.
Last edited by BlackML550; Mar 1, 2024 at 02:07 AM.
