I replaced my coolant twice, but after 3,000 miles it turns from green to light brown. When tested, it is still good, but the color has me concerned.

__________________
Jacob Wissler Jr., Houston, Texas, 1984 300 SD

Do you flush the system? How much do you remove/add each time?

Even on an iron head engine many folks prefer MB brand coolant to anything that's green.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sounds like some oil is leaking in there. If you've changed it repeatedly, it's not the coolant.

...my coolant was brown, then I realized I had a busted head gasket and oil was leaking.

It sucks, but as Mr. Bill would say: "It's just money."

I know, that's easy for me to say since I got mine back this week. It's a little less painful when you've survived.

Good luck finding out what it is buddy. I hope it is NOT a head gasket, but not many things can cause your coolant to be brown; especially after repeated changes.

I didn't even think of oil. I thought it was brown from rust.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

It is very, very light brown, almost clear.

__________________
Jacob Wissler Jr., Houston, Texas, 1984 300 SD

Our coolant was contaminated with a brown sludge on top, when we had a head gasket problem. Because it was oil, it floated on top in the resevoir, and coated everything. If yours is light and in suspension, it sounds more like rust.

Oil contamination also caused 'weeping' coolant hoses. If yours are dry and look in good shape after a hot drive, it is probably not oil, or has not been a problem for long, anyway.

Steve