I have a 2008 BMW 328xi and was just doing a basic drain / fill of the coolant today. Draining and filling the coolant is about the same on the xi it seems as the regular rear drive models, but one thing I noticed while I was down there was the front subframe on the xi model is very different. It seems like the front subframe completely blocks access to the water pump and thermostat. Has anyone changed these on their xi and can comment? Does it require dropping the whole subframe if they go bad?
No they are not to bad you just have to squeeze them out of a the tight spot by removing the thermostat first then the water pump. No need to drop the subframe but if it is out then the job is very easy. So if you had a oil pan gasket to change do the pump at the same time.
I have a Z4 - E85 and the dealer wanted over $1K to change the water pump. So, i did it and it involved loosening the driver side engine mount, jacking up the engine to squeeze out the water pump. It's the only way to do it. Not sure about your car but the process is not as bad as it sounds - took me about 5 hours for the whole job - pump, thermostat, and hoses.
