If coolant is overflowing, its normal for it to leak out by passenger front tire as that is where the over flow hose runs into a container to catch the fluid, but your container must be full, thus it pouring out onto the ground. As far as overheating, start with simple stuff first that doesn't require you to throw parts at the car hoping to fix it. Viscous fan clutch not engaging, thermostat by water pump housing not working, or even air in the system. Search posts by ps2cho because I think he has the same year and model as you and see if he has encountered this problem.

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1990 190E 3.0L