GL63 AMG and GLS63 (X166, X167) 2014 - present (Two generations)

2015 GL63 AMG coolant tank overflowing for no reason

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Apr 18, 2024 | 04:44 PM
  #1  
MX Junky's Avatar
Thread Starter
Newbie
 
Joined: Dec 2011
Posts: 4
Likes: 0
From: Huntington Beach, CA
2015 GL63 AMG and 2009 SL550
2015 GL63 AMG coolant tank overflowing for no reason

Hello, I have fixed many leaks and had the water pump replaces a year ago. Ever since the water pump got replaced, my coolant tank will randomly empty out one liter of coolant out of the over flow hole (no tube) on the the front right tire. I will fill it and it will stay dry for a day or two. Then I drive it for 5 miles and the low coolant light came on and the entire wheel well is wet and I'm down one liter of coolant. After cooling down, I will top it off and it will stay full for many miles and a few days and then randomly do it again in a short amount of miles. I will fill it again and it will last a day or to again. My mechanic can't seem to solve the mystery. I'm hoping some here has seen this before. Note, no leaks anywhere else. Sorry for the large photos.

Leaking off the wheel to ground and all down the side of the vehicle while driving

Leaking off the tire to wheel once parked

Spraying onto the wheel Well from tire while driving

Last edited by MX Junky; Apr 18, 2024 at 04:50 PM.
Reply
Old Apr 18, 2024 | 08:06 PM
  #2  
BlownV8's Avatar
MBWorld Fanatic!
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2003
Posts: 8,882
Likes: 1,212
From: In my garage
E55, GLS450, GL63, GLE350
Sounds like a failed coolant cap.
Reply
Old Apr 18, 2024 | 08:59 PM
  #3  
MX Junky's Avatar
Thread Starter
Newbie
 
Joined: Dec 2011
Posts: 4
Likes: 0
From: Huntington Beach, CA
2015 GL63 AMG and 2009 SL550
We have changed the tank and cap twice.
Reply
Old Apr 19, 2024 | 08:55 AM
  #4  
BlownV8's Avatar
MBWorld Fanatic!
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2003
Posts: 8,882
Likes: 1,212
From: In my garage
E55, GLS450, GL63, GLE350
Make sure you are using an OEM cap.
Reply
Old Apr 19, 2024 | 01:46 PM
  #5  
MX Junky's Avatar
Thread Starter
Newbie
 
Joined: Dec 2011
Posts: 4
Likes: 0
From: Huntington Beach, CA
2015 GL63 AMG and 2009 SL550
The new tank came with an OEM cap.
Reply
Old May 6, 2024 | 11:37 PM
  #6  
MX Junky's Avatar
Thread Starter
Newbie
 
Joined: Dec 2011
Posts: 4
Likes: 0
From: Huntington Beach, CA
2015 GL63 AMG and 2009 SL550
Well, My mechanic change the temperature sensor and $600 dollars later no change. Now we come to find out there is three radiators on this vehicle and an expert MB tech instructor believes that the system must be blead and it won't self bleed. I sure hope this it the case since I'm already $1,500 into this.
Reply
Old May 8, 2024 | 11:42 PM
  #7  
BlownV8's Avatar
MBWorld Fanatic!
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2003
Posts: 8,882
Likes: 1,212
From: In my garage
E55, GLS450, GL63, GLE350
I had no issues other than it being a total PIA changing the radiator on my 63. The system bled itself. If you do it, make sure you buy the right one. Like they said, there are three and multiple types and parts revisions. Figured the MB unit sucked so I purchased the cheapest one I could find on Ebay. Seems to be as good or better than the OE. Can't get worse than what they put in the car since they all seem to fail around 100k miles. The radiator for coolant is behind the fan and in front of the condenser. The condenser rides piggyback on the radiator, so it is a two-person job to get everything to line up.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 07:14 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE