I haven't change my coolant for ever since I got the car (a year ago). The coolant was very light green in the beginning almost water like. Then after about a year, it's now a very light brown. I don't see oil floating to the top, but it looks brown.

I did overheat maybe 4 months ago, but it was due to the fan not coming on (fixed). What could this be? I am not loosing any coolant at all. Temp stays fine. Gonna change it out and see what happens, but what could it be?

 

It needs to be changed....it is just dirty...change it and you should be fine.

 

Clean system... check every week for color change in your fresh coolant... if it still turns brown... it might be your headgasket is leaking... on the other hand does your engine smoke white ? Coolant leaking in your combustion chamber... ?

 

exactly what i was thinking too

 

No smoking. It's just the coolant. The coolant level seems to be the same and I am not loosing coolant. Although I am loosing oil, maybe a quart every 3000 or so, but I commute and the car is getting old. I'll check after a week from when I change it. Maybe just getting dirty like what the guy said above? Maybe Headgasket? Engine bay is really dirty though, so I need to clean it out anyway.

 

Maybe you had more water then coolant that recommended? Does it look like a rust color brown?