MB18436572

What you see here in photos is coolant is “seeping” from the corner of my rad at the location where the top rad support “holds” the radiator. No, it’s not residual from the hose rather I WATCHED the coolant seep slowly out of the top rad; dry it up and more flows…see photos. Was wondering if you folks have had this same issue? I have evidence of a leak in that area because there has always been a white lime look in that area. I let the car run and that’s the source. Need help is this a problem or can I drive it more before I decide to save up and pay a dealer to replace the rad. Let me know if it’s safe like that??

MB18436572

It turns out this rad leak (after searching and thanks to this forum) is a repetitive (quality) issue with the radiator. The failure is the radiator leaks coolant, out of the top driver side support post. It’s not definitive if the root cause of the problem is “manufacturer defect” per a particular supplier for the OEM. That is, I’m unaware if Mahle or Behr are the OEM supplier culprits for Mercedes and as such I lack knowledge whether data exists to show that the defect occurred while under the standard warranty period. In the latter case, the Mercedes Benz company would work with the radiator manufacturer to resolve the defect. What I do know is many owners on this forum have complained of the same exact (defect) radiator leak. My vehicle has just 57000 miles and I began to notice coolant puddle and the dreaded “low coolant” pop up on the center display. I’m unaware of whether Mercedes have voluntarily extended warranty on any vehicles for this issue. To search for other owners with same issue simply type “radiator leak” in our forum and you will find many examples of the exact same issue. Most customers on this forum reported replacing the radiator at their own expense while “breaking” certain fasteners or tabs, dealing with hardship of (a PITA “to quote one comment or”) repair. I’m most certainly going to contact Mercedes and determine whether the extent of the problem is planned to be covered. My concern that I will ask is whether a so-called Mercedes parts “replacement radiator” (resolves) or may still exhibit the same failure mode and or whether the replacement current art radiator has resolved said prior art failure. Remember, if you allow a normally closed loop system to “not” maintain pressure you lower it’s boiling point and essentially many of the catastrophic problems we see with these all aluminum engines (head gasket failures - misfire) often times are attributed to overheating - whether it’s a sudden loss of coolant, or compounded by a coolant leak condition that does not get resolved soon enough.

MB18436572

Attached are photos of same issue…obviously a vendor problem with design of radiator. Should be recalled….problem being closed loop systems that leak (are not intended to be that way result in lower boiling point and low coolant means overheating and blown head gaskets and resultant engine misfire conditions). Replacing a head gasket in these engines last I looked was “must pull
motor”. Root cause?

MB18436572

Tired of having coolant leak on my garage floor I elected to stop the rad defect (leak) using some JB weld. Now, you might ask why not replace the rad? Are you kidding me? If there’s a known issue based on the number of complaints and Mercedes “doesn’t have a recall I’m not going to install another defective rad!”. I “am looking for” an all metal (performance radiator) and at such time when I find one… I’ll install that one. Not worth replacing it with another rad prone to same defect as before. I say that because “no one” at the dealership or Mercedes corporate was able to confirm there a “resolution to the rad leak at the top mount”


.

Aldrich Chan

Hi @MB18436572
Which JB weld product did you use?
How did it hold?

WaveyKat

i had this same issue on my X166 and the JB weld Worked!

BourkevsGL63

Which JB Weld did you use? I was thinking of using their marine weld formula.

WaveyKat

the one i used was JB Weld Radiator & Plastic Tank Repair Kit