24 GLS580 coolant smell
Thread Starter
Newbie
Joined: May 2025
Posts: 12
Likes: 2
2024 MB GLS580 , 2016 E63 S AMG Wagon, 2011 BMW M3 Sedan
24 GLS580 coolant smell
In March my wife and I picked up our first MB. A 2024 GLS 580 with 5k miles and CPO designation by MB.
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
MBWorld Fanatic!
Joined: Jan 2023
Posts: 3,135
Likes: 1,205
GLE 580
In March my wife and I picked up our first MB. A 2024 GLS 580 with 5k miles and CPO designation by MB.
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
Out Of Control!!
Joined: Sep 2018
Posts: 14,694
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
German brands including MB use small electric coolant pumps for various little tasks. MB uses low quality hoses (biodegradable over the long term) and clamps which do not properly seal the hoses they are attached to. The net result is coolant “sweating” out of the hose joint at the small electric coolant pump. Sweating can be perceived by way of coolant smell and by visual presence of dried coolant residue. It’s a feature on this $100k car.
SPONSOR
Joined: Apr 2021
Posts: 846
Likes: 559
From: San Jose, CA
11 E550, 16 AMG GTS, 13 S550
Mercedes are always venting coolant one way or the other. I kind of hate it but I've been told its the additives in the coolant that make it do this
__________________
Alpha European Autotech
Purchase Amsoil at 25% off from me
Chris Tran, Retired Alpha European Autotech Owner
Amsoil Independent Dealer #7236674
Alpha European Autotech
Purchase Amsoil at 25% off from me
Chris Tran, Retired Alpha European Autotech Owner
Amsoil Independent Dealer #7236674
MBWorld Fanatic!
Joined: Jun 2019
Posts: 2,184
Likes: 973
From: Costco
2025 AMG GT 63, 2023 S500, 2022 GLE53
I smell coolant from Mercedes’ new I-6 engine as well in my S Class. It’s not always, but occasionally I’ll smell it in the garage after I just drove.
Chassis is correct in that a lot of coolant components are plastic. I remember the model Audi I had was notorious for their cheap plastic coolant pumps failing and one of the telltale signs of that impending failure was coolant smell. I hope the smell from our car isn’t indicative of the same type of impending failure issue.
Chassis is correct in that a lot of coolant components are plastic. I remember the model Audi I had was notorious for their cheap plastic coolant pumps failing and one of the telltale signs of that impending failure was coolant smell. I hope the smell from our car isn’t indicative of the same type of impending failure issue.
MBWorld Fanatic!
Joined: Oct 2009
Posts: 7,018
Likes: 2,199
From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
Make sure your reservoir caps are fully tightened.
They can seem tight, but you might be feeling a false detent. When tightening the cap, there's another 1/16 of a turn past that first resistance, to be fully tightened.
They can seem tight, but you might be feeling a false detent. When tightening the cap, there's another 1/16 of a turn past that first resistance, to be fully tightened.
MBWorld Fanatic!
Joined: May 2023
Posts: 1,125
Likes: 310
'23 GLS450
Trending Topics
Thread Starter
Newbie
Joined: May 2025
Posts: 12
Likes: 2
2024 MB GLS580 , 2016 E63 S AMG Wagon, 2011 BMW M3 Sedan
Thanks all for the help. I have asked the dealer a couple times to assess but they have not “found anything”. The smell is so clearly concentrated on the drivers side…
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Newbie
Joined: May 2023
Posts: 9
Likes: 1
GLS580
Possible
In March my wife and I picked up our first MB. A 2024 GLS 580 with 5k miles and CPO designation by MB.
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
I didn’t worry too much about mechanical inspections/issues when buying due to having the CPO warranty until mid 2029. However, upon getting the car home to WA from NJ and adding more miles. I am noticing it seems to constantly smell like coolant from the engine bay. So much so that I smell it on the inside of the cabin unless the HVAC is set to recirculation. Visual inspection doesn’t indicate any clear leak, spraying or weaping. The coolant level in the main expansion tank appears stable. However I understand there may also be coolant in the non-translucent reservoir on the drivers side, under the engine cover. I have not yet checked the level of that.
Have not taken it yet to the dealer but I plan to ask them to inspect and perform a pressure test on the system.
is this normal? I sure hope not for a 100k used car in service for less than 9 months…
about two years ago now mine developed a leak at the starter generator. Minor leak 1200 dollar repair. One of the connectors for the cooling system was leaking, repair done on after market warranty
hope this helps
MBWorld Fanatic!
Joined: Oct 2009
Posts: 7,018
Likes: 2,199
From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
An important thing is to make sure that you report it on a work order. Even if they "Can not duplicate," it's on your record and will give the shop ammo to file a claim even after the warranty/Service Contract expires.
