Brisk335

Alright so, i put 1 gallon of coolant into my resevoir tank.. Light went away but after a short drive it came back again, and i brought it to the dealer, they topped it off and it was all good. (no lights or warning)

After driving around today the warning came back on, and i had to add another gallon of coolant!. Went for a drive and again the light has come on i havent checked how much but the light has come on.

From the spots where i park my car through the day and my garage, there is no visible leaks anywhere on the ground.

Does the car really juss need this much coolant or where is it going? Im going to try again in the morning but if nothing comes of it, im gonna have to dealer it and the worst might be the coolant is leaking into the oil/tranny or something.

saziz

I'm having this same problem and have done everything to get it resolved. I'm seriously concerned since I have no warranty left. What did the members here experience in terms of Mercedes fixing the issue?
Thanks

vvrjrlaw

If you must consistently top off the coolant start looking for these signs: white smoke, oil in the coolant, coolant in the oil, pressure in the reservoir. All are symptoms of head gasket failure. Sounds like you must consider that possibility until it can be eliminated. Head gasket failure left unchecked will cause a catastrophic failure of the engine so check it out right away. And I hope it's just some errant hose that is dripping along the transmission and running to a puddle not directly under the engine. Good luck.

red60R

I had a similar issue with mine, found it was a leak on the radiator seam on the bottom of the radiator. Run your hand under the radiator and feel for fluid.
I would top off and within a few days the light would be on again. Ended up having to totally replace the radiator but no issues since.

ML63 AMG

If your motor is consuming a lot of coolant, I am sorry to say it but your but your head bolts have broken. In order to fix them you will have to completely disassemble the whole top end of the motor, take the heads off, replace all the head bolts with the updated design and new head gaskets and calve cover gaskets. You are easily looking at $3-5k minimum for the job.

Hope that helps

AMG893

Does sound like the head bolt issue to me.

Had the same on my old E63

saziz

Yes confirmed to be head bolt issue. - 4K