Coolant, here we go again
Thread Starter
MBWorld Fanatic!
Joined: Jun 2021
Posts: 3,123
Likes: 1,357
From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
Took it to my "Master Mechanic" already...Crazy freaking day with Mercedes Mechanics!
Said that I have a loose band clamp....so, now I get to tell stories about how when I got messing around with band clamp.....that one time.
So, shall cut it off and replace it with a screw type clamp.
All the while MB of Gainsville had called one of our clinics and let one of my staff members know they are sending a tech to replace an airbag in one of my cars (I have been ignoring the recall). I dont let them do is just because of how pushy they are. Hell, 9,000 post cards and on and on. Then they "Google" me (his words) and find one of my offices and talk to staff? Um, hard no.
Said that I have a loose band clamp....so, now I get to tell stories about how when I got messing around with band clamp.....that one time.
So, shall cut it off and replace it with a screw type clamp.
All the while MB of Gainsville had called one of our clinics and let one of my staff members know they are sending a tech to replace an airbag in one of my cars (I have been ignoring the recall). I dont let them do is just because of how pushy they are. Hell, 9,000 post cards and on and on. Then they "Google" me (his words) and find one of my offices and talk to staff? Um, hard no.
Senior Member
Joined: Jul 2022
Posts: 464
Likes: 99
2014 E63 / 2017 CLS 63 / 2015 G63
Took it to my "Master Mechanic" already...Crazy freaking day with Mercedes Mechanics!
Said that I have a loose band clamp....so, now I get to tell stories about how when I got messing around with band clamp.....that one time.
So, shall cut it off and replace it with a screw type clamp.
All the while MB of Gainsville had called one of our clinics and let one of my staff members know they are sending a tech to replace an airbag in one of my cars (I have been ignoring the recall). I dont let them do is just because of how pushy they are. Hell, 9,000 post cards and on and on. Then they "Google" me (his words) and find one of my offices and talk to staff? Um, hard no.
Said that I have a loose band clamp....so, now I get to tell stories about how when I got messing around with band clamp.....that one time.
So, shall cut it off and replace it with a screw type clamp.
All the while MB of Gainsville had called one of our clinics and let one of my staff members know they are sending a tech to replace an airbag in one of my cars (I have been ignoring the recall). I dont let them do is just because of how pushy they are. Hell, 9,000 post cards and on and on. Then they "Google" me (his words) and find one of my offices and talk to staff? Um, hard no.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2021
Posts: 3,123
Likes: 1,357
From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
Out Of Control!!
Joined: Apr 2019
Posts: 12,002
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
EVIDENCE OF RELIEF
-- A: shows cap venting pressure over the top instead of thru the vent discharge -- B: shows signs of pressure relief
Q: How much coolant is this engine loosing over a time period ?
Is this qualified discharge from multiple locations?
I used to be plagued by this feature under warranty but no longer have to deal with uncontrolled heat.
This pressure relief is the result of accumulated heat causing repeated heat soaks at engine stop.
> REALITY BASED OPINIONS...
Fixing pressure relief does not need to be an up hill battle.
Leaks evidence relief, applicable to both OIL & COOLANT leaks.
--> Oil leaks "may be" related to pressure.
--> Coolant leaks "may be" related to uncontrolled accumulated heat.
I find both issues are enabled by limited oiling setup.
HK Style: MB A-250
Last edited by CaliBenzDriver; Nov 22, 2025 at 10:03 PM.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2021
Posts: 3,123
Likes: 1,357
From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
@CaliBenzDriver That makes the most sense...happening in the garage parked. When I shut down my other E or our GLS I can hear water pumps a pumping. Never heard that in the E63. Might be sitting there baking....
So - there is or is not a water pump that runs on the battery when the car is shut down????
So - there is or is not a water pump that runs on the battery when the car is shut down????
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Out Of Control!!
Joined: Apr 2019
Posts: 12,002
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Accumulated Pistons Heat
@CaliBenzDriver That makes the most sense...happening in the garage parked.
When I shut down my other E or our GLS I can hear water pumps a pumping. Never heard that in the E63. Might be sitting there baking....
So - there is or is not a water pump that runs on the battery when the car is shut down????
When I shut down my other E or our GLS I can hear water pumps a pumping. Never heard that in the E63. Might be sitting there baking....
So - there is or is not a water pump that runs on the battery when the car is shut down????
You can experiment running pmp to see if heat soaks overboils stop.
Beyond that the main source of accumulated heat expressed after engine stop are the 8x pistons left ineffectively spray cooled at normal driving Rpm.
During Florida cold-snap you can pay attention to engine FAN RUNNING non-stop with same heatsoak overboil regardless of cold. That will evidence inability to cool regardless of cold weather.
The opposite is effective cooling without heat soaks overboil regardless of 100°F weather.
HK Style: luxury S-320 economical power
Last edited by CaliBenzDriver; Nov 24, 2025 at 02:17 AM.
