BMWs have weaknesses in their cooling systems that many owners like to address.

The complaint is the use of plastic in certain components, like the radiator, the water pump impeller and the thermostat housing. Those pieces can become brittle, break and cause a lot of trouble.

At about 80,000 miles I did a lot of work on the cooling system.

Here’s a video of the work I did.

I replaced the radiator on my (14 year old) 1997 M3. I also replaced the water pump with a Stewart High Performance unit and I upgraded to an aluminum thermostat housing. Of course, I replaced the thermostat while I was in there.