Hi,

My '84 280SL with M110.990 is mixing coolant and oil. Is this likely a cracked block or just a bad head gasket?

Has anyone experienced this on the M110?

Whatever the case, I think I'm going to have to pull the engine and do a complete rebuild. I've had problems with overheating in the past and I've replaced the thermostat and flushed the cooling system per the MB protocol in the past. I'm thinking that the worst case scenario is a cracked block.

My car only has about 60k on the odometer. It's likely been sitting too long.

Regards