W205 C63S Coolant brown

[K44HNO]

Hi

I have a W205 2019 C63S AMG, over a period of 2 weeks the coolant low warning comes on and the coolant has turned brown. I did have a misfire recently on a cold start amd engine light would come on I replaced a couple of coil packs as this is what was coming up on the star machine. Still same issue with misfire but have also noticed the coolant turning brown. Any ideas what this issue could be or checks i could do? Thanks

 

[Trickythemerc]

Could be oil contamination. Early signs of head gasket failure, what does does the the oil look like ? Keep a close eye on coolant level and get the system pressure checked for leakage.

 

[Behindthebins]

Hi

I have a W205 2019 C63S AMG, over a period of 2 weeks the coolant low warning comes on and the coolant has turned brown. I did have a misfire recently on a cold start amd engine light would come on I replaced a couple of coil packs as this is what was coming up on the star machine. Still same issue with misfire but have also noticed the coolant turning brown. Any ideas what this issue could be or checks i could do? Thanks

If you look from the side of the expansion tank or directly into it, does it still look brown or is it pink from the a different view point? I had same issue and it looked pink from the correct angle. Doesnt explain loss though. Although the tank screw down lids do seem to let out coolant.