Brown Sludge in Radiator ??????

[Chris McDade]

I took my radiator cap off and there was this dark brown sludge
(spelling?) on the botton of my radiator cap. I stuck my finger the the radiator and it's stuck to all sides of the radiator also. I run distilled water and RMI 25 with a little anitifreeze. Can some tell me it this normal when running RMI25? Is it a coating? It looks pretty nasty. It doesn't look normal to me. I don't have any problems with the car running hot. NO it's not milky like a blown head gasket.

Please help

Thanks in advance

 

[Steve Wood]

yeah, that is stuff that the RMI has cut loose and is keeping in suspension...it will rise to the top so you can overfill it and remove it

 

[Chris McDade]

Thanks Steve,
I will try to keep it clean. That stuff look pretty nasty.