1995 E320: Coolant mixed w/ oil

[juribe2]

Hi,

My first post (sorry, a long one) and my first MB. I got my first MB about a year ago. It's a 1995 E320 Sedan and I have had lots of trouble with the cooling system. I already replaced the water pump, top radiator hose and heater hose. Recently I got a mayor damage and the coolant became mixed with motor oil. First I thought It was a head or head gasket problem but after checking the head and replacing the gasket, the workshop found a leak in the intercooler system (I'm not sure if that's the correct name. It's like a small aluminium radiator inside the oil filter housing). I replaced the intercooler but now I have all the cooling system contaminated with oil. I have changed the cooling fluid like 10 times since then (3 weeks) but I still get oil floating in the coolant.

I'm thinkig about doing a cooling system flush (been reading a lot in this forum), but I do have some fears and some questions about the procedure. The radiator is 11 years old now and has never been flushed. The previous owner used only tap water in the cooling system with no coolant at all. That's really comon in my country and most mechanics say coolant is a waste of money (no winter here). I think that's the root cause of all my problems because of the lack of corrosion protection.

I'd really appreciate your help on this one:

1. I bought a can of radiator cleaner but I think it will remove all calcium deposits in that 11 yr old radiator and maybe cause lots of leaks. The radiator has no leaks at all and I don't want to buy a new one now. I already spent a fortune on the water pump and intercooler. I have the idea that using chemicals to flush an old radiator for the first time, will "kill" the radiator and cause lots of leaks.

2. I think a deoil (detergent) flush could be a better solution. I don't want to remove corrosion but to remove the motor oil contamination. What do you think? What kind of detergent (deoil agent) should I use? Is it ok to use one of those general purpose liquid degreaser used to clean in the kitchen?

3. My termostat is working perfectly. Do I need to remove it before starting the flushing procedure to get a good flow?

4. If I open the termostat housing, do I need to replace any gasket or o-ring or something?

Thanks a lot guys,

Juan