Just needing confirmation. I'm not mechanic and I'm getting mixed opinions from people I've asked.
1996 C220 with the 2.2l. Engine oil on the dipstick is clean, no coolant anywhere on it. BUT the coolant in the reservoir is brownish, and looks oily and some tiny chunks.
Car does not overheat, as far as I know, it has only ever reached about 90c on the temp gauge and stays there. I drove it to work (20 miles there, 40 miles total) to clean it the other day and it ran fine. Doesnt smoke either. Is this just dirty *** coolant? Or am I staring at a blown head?

Like I said, not a mechanic, worked on my own Lexus's though, but Ive never seen this before. Bit of a learning curve. Thanks in advance.