1996 Chevrolet Lumina Base 6 Cyl 3.10L
I used some stop leak for a coolant leak. Now I have brown sludge in my oilpan.
I kept having to add antifreeze. I could not find where it was leaking at, so I used a bottle of stop leak in the radiator. Now I have some kind of brown sludge on the dipstick when I checked the oil and I still have to add antifreeze.
The brown sludge is not a good sign and it indicates the cylinder head gasket has a leak - it means the leak is large enough to allow the engine oil to mix with the coolant - causing the brown sludge. The cylinder head gasket must be replaced.