I have a 91 318is that is M52B28 swapped. A couple weeks ago the fan stopped working while the car was idling unattended causing it to overheat and blow the heater core. At this point the heater core is fixed and I'm still working on diagnosing the fan. My concern is that white smoke/vapor is billowing from the exhaust and seems to get progressively worse as the car heats up. As I mentioned it's white smoke so I assume it's not oil smoke but it really doesn't smell like coolant. Like at all. There is a significant amount of water in the exhaust but it seems like to much smoke and even though I haven't let the car run for to long as I'm still working on bleeding the radiator I feel like the car has ran plenty long enough to burn water vapor out. My buddy says the motors toast but I'm holding out hope that it is just the vapor. Any ideas on what it may be would be much appreciated. FYI no coolant in oil.