Hello, I’ve had my 2018 C63S for about two months now almost. First issue that came up was a wheel bearing on the rear passenger side I had replaced. Now I’m fearing this coolant level issue which is bothering me. I had bought OEM coolant that’s recommended for the car and added to fill up the reservoir, bought a new cap for it as well. I checked about 2 weeks after and noticed the coolant went down a bit but not a crazy amount. I’m not sure whether it’s a leak , head gasket which is my biggest fear or something else. The car doesn’t smoke unless it’s cold outside and when it warms up after driving for a bit, the white Smokey condensation will disappear. I would add photos but I do not currently have any. Has anybody ever experienced this coolant issue? Or has anybody had any issues with their head gasket for this car? I’ll mention that the car does not overheat and runs fine.

 

First question is do you have a message that shows up when doing a cold start? Does it reappear when the engine is warm? Second Question, has temperature dropped by large amount recently?

 

it showed up once a couple weeks ago. Filled the reservoir since and hasn’t popped up. Temperature as in the weather outside has dropped by a large amount yes. Was 90f and now it’s about 40f outside.

 

I would say that its just a result of the cold weather, same thing happens with mine in the morning, and if you aren't getting the message now you have nothing to worry about. If you have to refill after your most recent reservoir fill something maybe wrong though.

 

This forum is dead but if you're losing coolant my money is on a puncture/leak in one of your front auxilliary coolers.

What's your transmission temperature saying?

 

My temps always sit at 183f

 

You're cool then. If you ever do see your trans temp shoot really high and stay there in just normal driving then that's a leak in your front coolers confirmed. But for now you seem good it's just a bit odd seeing your coolant warning come up unless the system was pretty dry.

Don't worry 👌

 

Thank you brotha. Appreciate the help very much. It’s just odd like you said for it to pop up without any issues. I’m having it pressure tested today to see what’s going on and if there’s any leaks at all. Other than that, the car runs great! My first Mercedes’ and I love it. You seem to be the go to guy in this forum!

 

Bro everyone else has disappeared. Not sure what happened!!

Congrats on your first Merc man what a start. I'm sure she'll be all clear with the pressure test 👍

Keep us posted!!

 

I haven’t been here long but I’ve noticed out of all the veterans, you’re the most active on here helping everybody out!

Thank you very much! Love this thing. It’s a bad *** car.

 

THIS FORUM IS DEAD!

 

*****It might get better.